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BMW Tech Letters

Mar 19, 2004

Function Over Form 101
I have a 2001 325i sport wagon with Hamann HM2 18-inch wheels, 3.0-liter Supersprint exhaust, Racing Dynamics R35 front fender/bumper, and clear tail/front/side lights. I'm thinking about Dinan cold air/wide throttle body upgrades.
1. I have this crazy desire to have the M3 like quad exhaust system even if it means having a dummy pair of tips. This is a real challenge but perhaps by having the right two tips not active it might still be possible. OK stop laughing. I prefer the closely spaced M3 style quad over the widely spaced 5 series effect although the latter may be easier to achieve on this car.
2. An easier mod I hope would be to install the E46 M3 side grilles on this car. How big a deal would it be for a body-shop to do this on my current fenders? Is it possible to retrofit M3 fenders on the sport wagon? Would the wider flares look too weird?
3. Do any tuners such as Hartge, AC Schnitzer, Racing Dynamics, etc., have 3-litre conversion kits for the 325i? Cheers,
Ciaran O'Byrne
Houston, Texas

Ciaran, I am about to save your soul. There are people out there--evil people--who place form over function. These are the people who bring us fake hood scoops, show with no go, 20-inch wheels on cars with the rest of the suspension falling out, flashing neon lighting--the list goes nauseatingly on. And it's not just limited to cars, either. The most obvious example is fake boobs, which have zero function. If anything, they inhibit function. This whole form over function business is denigrating the overall function of the human race. It is E-V-I-L. And yes, even BMW has engaged in it. 1. The M car quad tailpipes, at least in regards to the E46 M3, have been shown by Dinan Engineering to actually reduce horsepower. Visit and go to whitepapers/e46m3exhaust. In the course of extensive research to construct a power-enhancing aftermarket exhaust system for the E46 M3, the factory quad tailpipe arrangement was revealed to be counterproductive. Steve Dinan's E46 M3 muffler eliminates one opening, but they too indulge the nonfunctional by including your dummy tailpipes. Thus, they are not only nonfunctional even on the M3, they inhibit function just like fake boobs. The only thing cornier than four tailpipes that reduce horsepower would be four tailpipes where two are fake. Sorry Dinan, but we have to call 'em as we see 'em. Personally, I wouldn't be able to sleep at night if I had fake tailpipes on my Bimmer. My best advice is, stick with your Supersprint muffler. My second best advice is, contact Dinan Engineering, which, in addition to their many accolades, now holds the distinction of being the world's foremost expert in fake BMW tailpipes. 2. The fender part numbers are different from the coupe to the sedan and wagon. In fact, the wagons have two different sets of fenders, one up to 09/01 production, and one set after. I have no idea what the differences are, but I'm going to speculate that the M3 fenders and not interchangeable with the sport wagon fenders. Yes, the flares would look weird only on the front. With enough money, anything is possible, so it a highly skilled custom bodyman could graft the vents onto your existing fenders. However, the fenders would surely have to be removed. This is my rust belt conscience speaking: It would be a shame to break the factory fender corrosion protection seals just for something like this. Veterans of the Rust Wars think that way. 3. No one we know of has a conversion kit to make a 2.5-liter engine into a 3.0-liter engine, but you don't need one. Just get a 3.0-liter engine, harness, ECU, and front exhaust. Now, go and sin no more.
Best regards,
Mike Miller

2017 BMW 3-Series
$33,450 Base Model (MSRP) 23/35 MPG Fuel Economy

Bienvenue au France. Zee American Headlights Must Go!
I tranported my 1998 318ti to France, and a garage is telling me that I have to make a lot of expensive modifications to my headlights and rear lights. I understand that certain modifications are necessary, but how do I know that this garage is not taking me for a ride? What are the real rules for making changes to lights to conform to European standards? After all, it is a German car. Thanks.
K. Ducassou
via the Internet

The shop is correct. Unfortunately, automotive lighting regulations are not standardized throughout the world, and U.S. lighting does not comply with French law. You will need to replace the complete headlight and tail light assemblies. In the rear, you'll get rear fog lights integrated into the assemblies. You may also have to remove the side marker lights, but I'm not sure France requires that. Germany does. On the bright side (Ha!) you'll wind up with superior lighting. Contrary to popular legend, very few shops actually create work. Most legitimately have more work than they can do.

Double VANOS S50?
I would like to know if it is possible to convert a U.S. version 1995 M3 to double VANOS from the European version. What would it take to do so? Can it be done without swapping the head also? Is it really expensive? Please if you can give me all the details, even if it's not possible. I really appreciate your help.
Tomas Gnther
via the Internet

I don't know of anyone who has attempted this work, but I can tell you that you would need the European version cylinder head, plus many other parts. The bottom end isn't identical to the U.S. version either. This would be a trial and error process, most likely heavy on the "error" part. Tomas, I think it would be easier and less expensive to install a complete European specification S50 engine, assuming you can find one. Of course, you'd also need the intake system, all the engine ancillaries, engine wiring harness, and the ECU. But what is it exactly that you're trying to accomplish here? If it's more power you're after, you might want to consider a supercharger on your existing engine.
Best regards,
Mike Miller

Swapski of the Dayski
Hi great mag! I own a 1994 BMW E36 320i. My engine has pretty high km. A local shop has informed me that they have a 1996 low km 2.8-liter M52 engine block. Is this type of engine block swap possible or even worth trying?
Raphael Jimenez
via the Internet

Thanks Raphael! You don't say what country you're writing from, but since you mention km and have an E36 320i, I'm going to assume you are not in the US. If not, there's no problem with this swap. But it is also unclear whether you're proposing swapping an entire engine -- block and cylinder head, or just the engine block. The 2.0 and 2.8-liter heads may be different, but without knowing your country I can't say for sure. Moreover, if your 2.0-liter head has very high km it is probably in need of a valve job so I wouldn't bolt it onto a fresh engine even if it would work.
Best regards,
Mike Miller

Your Typical Idle Control Valve Problem With a Relay Chaser
I have a 1993 325is with a problem and no one knows what to do. At start up sometimes the rpm's shoot up and down from 1,000 to 2,000 for about ten seconds and the check engine light will come on and then go out. After that the car will drive fine. Also the car will shut off at anytime, but this doesn't happen often.
Kevin Mejia

Your surging idle at startup is most likely the idle control valve, which is located under the intake manifold. Sometimes it will continue to work for a while if you remove it and clean it out, but eventually you'll need a new part. And for what it takes to get at it on this engine, I'd just replace it. The shut off problem is probably a faulty main relay or fuel pump relay -- another common problem at high mileages. I recommend preventative replacement of these relays every 120,000 miles.

But, But, But...
I have had a weird no start condition with a 1995 M3 automatic. I took it to the dealer and independant mechanic they could not duplicate it. If you put the key in the normal lights come on and an audible click is heard from the solenoid but nothing else happens. Out of curiosity I tried to jump start it and it started right away. So battery right? I took the battery to my battery dealer (it is a red top Optima), and they said it checked out fine. I removed the aftermarket alarm and valet box it came with. The valet had water damage on it but it was under the air conditioning duct so I think the ECU is fine. Any thoughts?
James X.D.

James, you didn't tell us if the car starts without the aftermarket alarm system installed! If so, then I think you've found your problem. Aftermarket alarm systems, audio systems, and cell phones often wreak havoc on BMW electrical systems if installed by a hack. If the car still doesn't start with the alarm removed (in which case it would be an intermittent problem because the techs couldn't reproduce it), then I would suspect the starter. However, you also haven't told us how many miles are on the car so we can't tell if your in the lane for starter replacement mileage-wise, which would be over 150,000 miles.
Best regards,
Mike Miller

Every Car is Different
I drive a 1992 E36 318i Saloon with the M40 engine. I recently upgraded to AC Schnitzer 17-inch alloy wheels for my Goodyear Eagle F1 GSD3 225/45/ZR17. I use Boge monotube gas absorbers (stock). All was well with this setup untill I lowered the ride a few days ago. I used B+G lowering springs (Sweden company) because Eibach's ride is a little too hard for me. The spring was supposed to give a lowering of 30mm front and 15mm rear. The car looked perfect except the left rear tire (physical orientation) scrapes the fender. Visual inspection showed the camber might probably be way off. I brougnt to the tire shop and he said the following (also my question):
1. Lowered BMW will cause extreme negative camber in front and rear.
2. there is nothing that can be done for this
3. In some cases the front suspension need to be pumped to allow proper fitting.
4. Fender rolling is A MUST when fitting 225/45-17.
5. I should have fitted 225/40-17 to avoid fender rolling.
6. The front left wheel is also a bit too negative camber, but it doesnt matter as long as I dont mind increased wear and rotated more.
7. I should have put 215/45-17 in front to avoid scraping the front fender (my front right does this when parking in tight spaces)
I really thought lowering was a no brainer. Now there is a whole new issue of negative cambering. The ride is also "feeling" soft and I will be getting front and rear suspension mounted strut bars (not sure of type and make). Also, waiting eagerly on the next installation of project 325. Its taking you guys too long!
Kuala Lumpur, Malaysia

Wayne, every car is different, and re-engineering BMW engineering is never a no-brainer. You need to either know what you're doing or, preferrably, use a technician that knows what he's doing with these cars. That may or may not be possible where you live. I'm not familiar with B+G springs, nor do I know what your ride height was like with the stock springs -- BMW uses different coil springs in nearly every market place. With that said, lets take your questions in order:
1. Any car with independent suspension will have increased negative camber when lowered -- it is a geometric certainty. With increased negative camber comes better cornering, increased tire wear on the inside tread, and, depending upon the degree of increased negative camber, sometimes an increase in straight line braking time and sometimes inside rubbing problems. Each car has to be taken individually. When we recommend a suspension set up, it is with the knowledge provided by having seen, tested, or installed the same set up on US cars.
2. On some cars camber can be adjusted, on others it cannot be adjusted. Some cars require special parts to adjust camber -- yours is one.
3. I don't know what they mean by "pumped."
4. I disagree, at least not on any E36 I've ever seen lowered with the springs we commonly use in the US. BMW actually approves fitment of 225/45-17 tires on the E36, at all four corners (assuming you follow their direction for wheel sizes and upgrading the suspension to M Technic parts and alignment specs).
5. See 4.
6. I agree generally, but you didn't provide the actual camber specs on the car so I don't know whether it's excessive.
7. See 4.
I see only two possible explanations for your problems. First, it is possible that the springs you used lowered the car too much. Second, it is possible that the wheels you installed have the incorrect offset or their width is too great for this application. For an E36 3 Series with 225/45-17 tires, you want 17x7 or 17x7.5" wheels with, ideally, a 41mm offset. You didn't tell us your wheel specs. Another unrelated issue is that your stock BOGE shock absorbers are totally overwhelmed by this combination of low height/high rate coil springs and heavy wheels and tires, and the stock shocks are also probably worn out at this age. I'd recommend you use Bilstein Sport shocks ideally with such a combination of parts. Also, replace the rear shock mounts with E46 parts using Z3 reinforcement plates, and install 1996-1999 front upper strut mount reinforcement plates. You're greatly taxing the front and rear control arm bushings, and I'd recommend you replace them with E36 M3 parts in the front and E46 M3 parts in the rear. In the rear, the bolts must be torqued with the suspension in normal operating position, not full droop. Not sure if your tech knows this, but it's important. Now, damage control. First, figure out what size and offset wheels you are using. Second, speak with someone locally who has used the springs you used in a similar car, and see what their experience has been. Proceed from there. Now, if you want to adjust rear camber (bearing in mind that once you lower an E36 you should be using M3 alignment specs), you can buy adjustable rear trailing arms from BMP Design ( in the U.S. I hope this helps you out somewhat. The key to your letter was that you thought this would be a no-brainer. There are a lot of people out there who have very little idea what they're doing trying to modify BMW suspensions, and that's not a good thing. They rely on Internet legend and often reluctant technicians who've never done the work and don't know the tricks -- also not good. Folks, e-mail us BEFORE you buy parts!
Best regards,
Mike Miller

STX 328i Mods
I love the magazine; it is one of my favorite reads. I am campaigning my E36 328is in SCCA STX class and I was wondering a few things before I spent the money on upgrades:
1) The rules for STX say that I am able to install any type of seat with padding as long as it weighs at least 15 lbs. From your experience, what seat would you recommend for this type of driving. Keep in mind that this car is my daily driver, but I am only 20 so I don't need all the comfort in the world. 2) I am also trying to find a way to turn the open differential into a limited slip unit. I would love to stick a 3.15 in for the 2.93, but the rules say that it has to be the original gear. To be honest with you, I am a little stumped on how to do this upgrade cost effectively. Do you have any suggestions on what to do, that are not too expensive College students don't have too much money, you know. Thanks in advance.
Bryce Merideth

For decent performance seating at bargain prices, I've always preferred Corbeau seats. Check them out at Cobra seats are also very good -- However, there is absolutely no denying the quality, fit, and durability of higher-end seating like MOMO, Recaro, and Sparco. BMW dispensed with the limited slip differential starting in 1996 except for M cars. This travesty went totally unnoticed by the elite automotive press. Apparently, not many of today's BMW buyers know or care what a limited slip differential is -- or was. Enthusiasts simply swap in M-car diffs, but racing rules sometimes leave us spinning our wheels -- literally. Unfortunately, your only option with the E36 2.93 is custom installation of a Quaife automatic torque biasing differential unit. I'm not sure this is SCCA legal in STX, so check that out. Also, you can forget about Spring Break 2004, because this job is going to cost you well into the four-digit range.

I own a 1993 325is 5-speed. I have Turner Motorsport's M3 cam kit with the custom chip. What BMW specialty tools will I need to install the camshafts? Do you guys know where I can buy these tools for a good price? Thanks for your time.

This is a job for a professional BMW technician, Eugene. According to our service information, two special tools are required -- an enormous camshaft fixture and a tool to secure the hydraulic valve lifters. The only place I know you can get these tools is your local BMW dealership. I'd estimate cost to be about $1,500. One reason head work costs so much on these cars is because the shop has to pay for the tools.
Best regards,
Mike Miller

E30 318i: Money to be Saved
I have a 1984 318i automatic. What is my best bet for swapping in a newer motor? The current motor is leaking badly and I would like to get some life back into this car I picked up for $300 at auction. Or would you recommend a place to find the same motor but in better condition. Thanks!
Nathen Markus

Well, it really depends upon what you want to do with this car, Nathen. If this is a $300 beater to you and the engine is in otherwise serviceable condition, replace the leaking gaskets and seals, tune it up, and drive it. It doesn't owe you anything for the price. If you've got a VISA card burning it's way out of your wallet, the versatile E30 chassis can accept and handle almost any BMW engine. However these swaps often necessarily entail entire drivetrain transplants along with brake, suspension, and tire upgrades. The sky is the limit on pricing, and the hardest part is finding a technician willing to take on the project. It is difficult to find a used M10 318i engine in good condition, as the newest one is now 20 years old unless you totally luck out and find one that's been rebuilt. Moreover, the cars are so underpowered that we had to beat the ever living snot out the engines to make them accelerate in the same week we needed to get there. But hey, for three hundred bucks it's hard to go wrong.
Best regards,
Mike Miller

Superfly Wheels
I have a 2000 323Ci. A store employee told me that Nito NT-555s will be able to fit 20-inch wheels. I would like to know if you have heard anything about that and what you would reccomend regarding 20-inch wheels
LCPL Donald L. Horne, USMC

The Nitto NT-55 Extreme ZR is available in some 20-inch sizes, but the largest E46 3 Series fitment we've seen so far is 19x8.5/9.5-inch wheels with 235/35-19 front tires and 245/35-19 rear tires. Even then, there is no guarantee and plenty of likelihood that you would have to roll the fender and quarter panel lips for added body clearance. Tires and wheels this big and heavy would also totally overwhelm your stock shock absorbers, so an upgrade there would be highly advisable. If you lowered the car with shorter, stiffer sport springs at the same time, the tire clearance issue would become more pronounced. You would also want to upgrade front and rear control arm bushings to M3 parts, and align the car to M3 specs. Lance Corporal, in my opinion "Superfly" wheels are more grief than they are worth. Performance-wise, a 323Ci with 17-inch wheels and four 225/45-17 serious performance tires has more rubber than it knows what to do with. Anything larger than that is mainly a styling statement.
Best regards,
Mike Miller (JO2 USNR)

323i vs 325i
What is the difference between the E46 BMW 323i and the E46 BMW 325i? Both have 2.5-litre engines. I am baffled. Can you please explain? In your opinion, which is the better vehicle?

Good question. The E46 323i/Ci was sold in America in 1999 and 2000. From 2001-on, BMW brought us the 325i/Ci. Both engines displace 2.5-liters, but that's where the similarity ends; these are completely different power plants. Vice the previous M52 engine, the 2001-on M54 2.5-liter engine employs a fully electronic throttle system replacing an electromechanical throttle. It is "drive-by-wire." This allows closer control over throttle input by electronic driving aids such as DSC and ASC, as well as the top speed limiter. Throttle-on/throttle-off transitions are also more closely regulated. Cruise control, ASC, and DSC, are now integrated into the engine management computer (ECU). This reduces complexity, but also gives the ECU more ways to fail. The M54 also has a dual resonance intake manifold for improved low-end torque, along with increased valve lift for better top end torque. A steel liner sleeved aluminum engine block reduces weight, and double VANOS further enhances available torque. The thermostat is now electronic, controlled in response to coolant and outside temperature, engine loads and engine speed rather than coolant temperature alone. On the road, this adds up to 14 more horsepower and 6 lb-fit LESS torque (184 hp @6,000 rpm, 175 lb-ft torque @ 3,500 rpm). The engine is a bit more peaky, but double VANOS distributes torque so well you won't notice it. The essential benefits of the M54 engine over the M52 engine were benefits to BMW, not the driver. Further electronic management means BMW can more closely monitor and control engine operation, which benefits the company in four ways: 1. Risk management in litigious America, 2. Emissions, 3. Fuel economy, and 4. Reduced production costs. I don't know that one of these engines is preferable over the other. I think the M52 is the simpler of the two and will be less expensive to repair as the cars age. Whether that's a factor in your decision really depends on you more than these two engines.
Best regards,
Mike Miller

Engine Swap Question Number 1,000,000
Hey guys! I enjoy reading your technical letters and appreciate your knowledge of the BMW. Apparently my knowledge isn't that advanced yet. I have a few questions. I have a 1993 BMW 318i four-door five-speed, obviously with the M42 engine. I have an M50 engine from a 1992 BMW 325i waiting in the garage. I know I will need to change the engine wiring harness and D.M.E, engine mounts, and exhaust. I am a little unclear as to what else I need to change in order to make the swap a sucessful one. Help me out guys, I'm tired of the wimpy 1.8 liter.
Harrisburg, Oregon

Congratulations, Trace -- you're our one millionth engine swap question! You win a free singed copy of the New York Times Best Seller, Why Not Just Buy an M3? by I.P. Money. One nice thing about the E36 M3 is that BMW sold a gergillion of them in the U.S., and thanks to the E46 M3 prices are now falling faster than panties at an NBA party. However, since you already have your M50 (and a cool one at that -- 1992 with the good cams, hot vavle springs, and no VANOS), you might as well slide it on in there. It sounds like you have the under hood part covered, except you'll need the radiator, hoses, and engine ancillaries such as the alternator, power steering pump, air conditioning compressor, and associated parts. You're going to need front springs and strut assemblies for an E36 325i as well, but that's about it as far as I can tell.

E36 Ball Joint Replacement
I have a 1993 325i and I need to replace a ball joint. How do I remove the old one so I can install the new one?

E36 ball joints are pressed into the control arms. The factory procedure for replacing them is to simply replace the entire control arm, with both ball joints for that side already installed. However, aftermarket ball joints are available individually for less money but you'll need a hydraulic press to use them. Aftermarket ball joints are attractive for the E36 because, well, these parts don't last very long no matter where you buy them -- factory BMW or otherwise. We do note that Meyle aftermarket replacement ball joints for the E36 employ a different design that is hoped to be more durable, and they are approved by TUV. Check them out: The problem is finding them for sale in the US.
Best regards,
Mike Miller

Professional Service?
I live in Italy and I have a 1990 520i. I want to know if this car is similar to the 525i because I just bought parts for my 520i going off a parts list for a 525i, same year of course. The parts are for the ignition sytem, normal "tune-up" parts. wires, cap, rotor and plugs. I also was able to get an oil filter here in Italy for the car, I was draining the oil and wanted to change the oil filter but I cannot find it. I was wondering if you could let me know where it goes. This is the first Bimmer I've owned and dont know much about it. Pretty sad for somone that built a hemi!
Jason Fitch

A 1990 520i or 525i, ECE version, could have either an M20 or M50 engine, which are completely different. Essentially, if you have an aluminum valve cover and a cap and rotor, you have an M20 engine. If you have a black steel valve cover with one coil per cylinder and no cap and rotor, you have an M50. I suspect you have an M50, because the M20 spin-on oil filter location would be obvious to a domestic car person -- right under the exhaust manifold. The M50 engine uses a nice canister insert filter on the left front of the engine. These same things lead me to believe you bought parts for an M20, none of which will work on an M50. Jason, you might consider professional service on this car. An E34 5 Series is not a good BMW to cut your teeth on without direct supervision from a knowledgeable enthusiast. If you're going to work on it yourself, get a Bentley E34 5 Series Service Manual ( It doesn't deal directly with European versions, but it will be better than nothing and most items are very similar.
Best regards,
Mike Miller

HFM Works, But...
I have a 1989 325ix and have been desiring a bit more performance lately. I have installed a Bavarian Autosport Tri-Flow exhaust and a performance chip. Lately I've been trying to come up with a relatively inexpensive way to improve the intake effiency. I noticed my stock air flow meter has about a two square inch opening. Even with little tuner experience, I can tell this is very inefficient. My question is, is it possible to take the old AFM out and cut/splice in an HFM from an E36 or even E46 considering both use four prong connectors? I'm not too concerend about the space, thats always managable. I'm just wondering about the ECUs abiltiy to recognize it.
Adam R.

Anything is possible for an electronics engineer, Adam, but for the rest of us it's not nearly that simple. The HFM systems on modern Bimmers do not operate by themselves. They work in conjuction with many electronic components including the control module. You can't just bolt it on, splice it up and make it work. Howerver, you have correctly isolated the air flow meter as the most restrictive part of your intake system. There are aftermarket HFM systems out there that do work, however they take a great deal of fine tuning and even them they are not nearly as durable as the factory AFM. And even after you've spent all that time and money, you're not going to turn this engine into an S54 M3 plant. Unfortunately, you're limited by the technology BMW used to build your engine in this model year. You've basically already done the things you can do to increase performance on this engine without an internal rebuilt including European-specification high compression pistons, some head work, and a Schrick camshaft, not to mention some exhaust manifold porting.

Hypoxic M3 Seeks Flatland Fix
I have a newly aquired 1995 M3 with 62,000 miles. I live at 7,000 ft. I was wondering how to best tune this car for power to bring it closer to sea level figures. Do you think I will get more power than usual out of a high flow cold-intake system and free flow exhaust compared to someone at sea level. I have heard this is true with forced induction but would it also be true for this cheaper alternative? Any other ideas for tuning at altitude would be greatl appreciated. Also, what are the best snow tires for this car?
Robert Miller

Robert, I can tell you how to get some more power, which is fairly easy, but the basic problem of less oxygen is always going to be there with one exception. The standard modifications on any modern BMW engine are a performance ECU chip or software download and a free flow exhaust system. If you are ready for the exacting maintenance required by a cone-type open element oiled cotton gauze air filter, that can help, too. Supercharging is always going to make more power, but it can't create oxygen. While you'll get more zoot than you have now, none of these mods are going to make as much power at 7,000 feet as they would at sea level -- that's just the way it is. Now, turbocharging is another matter, because turobchargers loose less performance at high altitudes. See, an engine compresses the air-to-fuel mixture in the combustion chamber to a given proportion, in the case of the S50 engine that would be 10.5:1. This is the compression ratio with the piston at the top of the compression stroke. Now, if you start with thiner air the compressed air will also be thinner -- there is simply less oxygen. This means your compression ratio is effectively lower, which is essentially why the engine makes less power -- that and the ECU is now leaning out the mixture to prevent the engine from running rich. However, a turbocharger works against the atmospheric pressure (it is barometric instead of volumetric). So, while a turbocharger would also have thiner air to compress it can compress it better relative to ambient pressure, yielding the same amount of oxygen regardless of altitude. This is why piston aircraft engines are often turbocharged. I hope this explanation makes sense. I'm not an engineer; I see this stuff in my head. But if you think you have it bad, try driving an old Bavaria up there with triple Weber side draft carburetors and a box full of jets in the trunk next to your Unisyn. Every few miles you can pull over, rejet your carbs, and pretend you're Dennis Wilson in Two Lane Blacktop! Now, where to get a turbo kit for the S50 engine? Visit Active Autowerke at While it is theoretically a "kit", installation is a major undertaking. Expect to pay between $7,000 and $11,000 just for parts, depending upon how much power you want.

False Warnings
I have a 1992 BMW 325is with an automatic transmission. Sometimes when the engine is cold, I get a warning message that the electro-hydraulic shift control has failed (the symbol looks like an exclaimation mark). What causes this and do I need a whole new transmission?
Jonathan Talbain

If the transmission is shifting normally, the problem is most likely an electronic anomoly or brought about by low voltage, which can wreak havoc on electronic cars. Check battery voltage using a digital voltmeter under static and loaded conditions, as well as alternator function, pursuant to the procedures set forth in the Bentley E36 Service Manual ( Unfortunately, a warning light in a BMW more often signals a problem with the warning system itself than with the system it was designed to protect. If the transmission is malfunctioning and not shifting normally, then yes, you most likely need a new unit. We tend to see a service life of 80,000 to 120,000 miles from BMW automatics. BMW manual gearboxes can last much longer if maintained with lubricant changes.
Best regards,
Mike Miller

Do you know of any web sites where I can find wide body kits for the BMW E30 3 Series?
It seems like the "wide body" styling fad was always largely confined to Asian marque enthusiasts. There was some spillover into the BMW world, but the only manufacturer that had a product line broad enough to reach back to the E30 was Erebuni, which is now out of business. Korman Autoworks ( had and may still have a fiberglass E30 M3 lookalike kit -- everything but the roof. BMP Design ( has some nice pieces they make inhouse -- front air dam, rear spoiler, side skirts, but it's not a "wide body." Similarly, Bavarian Autosport ( has about the largest selection of BMW aerodynamics available in the US, but no "wide bodies." First, you should probably visit
Best regards,
Mike Miller

Strange E30 Instrument Cluster Problem
I own a 1989 325i that I bought a few months ago. At the time the speedometer was not working. After replacing several fuses it began to work again. A few weeks later it stopped and then was followed quickly by the tachometer. The tach reads about 1,000 rpm when the key is at position 1, and it stays there. I checked the SI board, which I learned was the cause of many such problems but is still good. My brother has a 1991 318i with the same problem.
Aaron Thomas

I suspect your problem is the instrument cluster motherboard, which is actually pretty rare on the robust E30 -- it's even weirder that your brother's car has the same issue. This requires hands-on disassembly and diagnosis, which I recommend you have performed by a professional BMW technician, dealer or independent, BEFORE buying parts.

Would you please recommend some web sites for companies with good performance upgrade parts for the 1985 325e?
Ian, a Brit

Ah, an easy questions! Here you go:

This is just a smattering. Check the advertisements in European Car for more.
Best regards,
Mike Miller

E34 525i Computer Reset
Can you help with procedures on how to reset the oil/service computer on the E34 525i BMW 1988/89 models with 2.5-liter M20 engine?
Brisbane, Australia

You need a tool for this, Carlos. I have no idea where you'd find one in Australia, but many of our advertisers do sell them. Check out,, and
Best regards,
Mike Miller

Engine Swaps: Sometimes More Grief Than They're Worth
I was wondering if it was feasible to put a 1993 M5 S38 engine into a 1990 525i. The engine will come with a Getrag 280/5 gearbox a Bosch Motronic ECU, oil cooler, headers, alternator, pumps, and AC compressor. Would it be too much trouble to get it to work, or would it work without any trouble? Thank you.

Engine swaps never work without any trouble. But before you even get there, let's talk about the rest of the parts and work you'll need, and this is by no means an all-inclusive list: Radiator, coolant hoses, fuel hoses, engine wiring harness, shifter parts, differential, exhaust system front to back, instrument cluster, brake upgrade, wheels and tires that fit over the bigger brakes, four wheels suspension upgrade including shocks, springs, bushings, and sway bars to handle the extra power, and a four-wheel alignment. There's more, no doubt. The hardest part would be finding a technician willing and qualified to do the work. This is a lot of grief to go through when you could just buy an E34 M5 already built by BMW. The only advantages I can see to this conversion over buying an M5 would be insurance cost and tax avoidance, both of which would arguably involve fraud. It's certainly not going to cost less than selling the 525i and buying an M5. And you'd wind up with the cool M5 interior and aerodynamics as well.
Best regards,
Mike Miller

Some Things You Can't Do South of the Border
I just bought a 1996 328is manual with just 20,000 miles. It is in perfect condition and I'm going to use it as my second car. Because this car is Mexican-specification, is rated at 194 hp insted of the U.S. 190 hp. I guess there are exhaust restrictions in the U.S. I'm looking at getting a Conforti chip and wondering if it'll work on my car, and, if I change back the program later on, would it return to 194 hp or would it change to 190 output? If I change the chip, would it make a difference between bolting a Conforti cold air intake or a Racing Dynamics? Also I would like to know if I can get any hp by removing the catalytic converter, and bolting after it either a Borla cat back or the original muffler, and if there will be problems with the oxigen sensors. Thanks. Great work with your magazine I read it every month.
Ruperto Garza
Monterrey, Mexico

Thanks for writing in, Ruperto. We're glad you like EC! We discussed your question with Doug Mahar at Turner Motorsport Unfortunately, Mr. Conforti's chips and software programming devices only work on U.S.-specification BMWs, which yours is not. The ECU program is blind to the type of air intake on the car, so it wouldn't matter which one you chose. There's not really much to be gained by just removing the catalytic converter alone unless it's clogged, which it probably isn't at only 20,000 miles unless someone fed the car leaded gasoline. However, you can free up some power by installing Supersprint racing headers in place of the exhaust manifolds and downpipes. That's where the restriction is located. You will have to retain the oxygen sensors. The headers have fittings for them.
Best regards,
Mike Miller



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