Are you guys afraid to drive our car really hard? How long will the engine last?

[m3cowboy]

Hey guys. Recently i've been pushing the car really hard everytime i drive it. Basically going up to 6000/rpm on first and second... at least 7 or 8 times a day... just flooring the thing. Damn its really really fun but i'm thinking maybe its probably gonna stress out the engine pretty badly. How do you guys drive? and do you think its really bad for the car or am i just thinking too much?

[xeler8]

Dont worry about it man... with good preventive maintence your engine should last a long long long time

Jason

[DrLivingston]

I'm no BMW tech, but I heard somewhere that if a Bimmer is NOT drivin hard for any period of time (because they were meant for 100+ mph cruises in Germany) thats actually counter productive on the engine. So go rip it up, just make sure your not fryin cluthes and killing your tranny ;)

[Zaks]

i take mine up to redline 1-2-3 on average i think every other day, sometimes it's like 3-4 times in one day. i don't think 6000 is bad but i wouldn't do it 7-8 times every day. your car though, do whatever you want, as long as it's fun haha

[M52 POWER!]

I drive my car very hard and have owned it for 3 years. It somehow puts down more power than it should (for the mods I have) and compression test I got very good very high psi results (220-225)!

Driving the car hard blows the buildup of carbon and other gunk out of the engine.

[bimbum]

You'll see that at the dyno too first couple of runs a lot of cars blow crap out the back then all clean runs after that. Make sure the car is warm before you start stomping on it. Also I think cruising all day at 100+ is way less stressful on a car than doing 0-100-0 start and stops.

[morerevsm3]

my car has revlimiter at 7500 soft cut, 7800 hard cut, this is how I always drive it, 50 passes at drags, 2 hillclimbs, 8 track days, and 8 autox days, + 27000 miles hard road driving in last 12 months, car seems to thrive on it
http://www.e36fanatics.net/media/video/deca/DECA_morebeer.mov
http://www.burnoutsunlimited.net/video/as/Picture199.MOV
http://www.burnoutsunlimited.net/video/as/Picture200.MOV
http://www.burnoutsunlimited.net/video/as/Picture202.MOV

[korto]

Well, the engine feels very balanced at 3000+ RPMs... Also, my feel is that it should not be driven crusing around in high gear and low RPMs...
Make sure the engine (oil) is fully warmed up.
The KEY is your OIL temperature - My coolant temperature gage is at the middle within 10 minutes, but OIL needs at least 15-20 minutes if not more - with outside temperatures around 0 celzius now.

[beatniks325]

Make sure the engine (oil) is fully warmed up.


the most important thing right there.

[Trackout]

M3Cowboy dude. Just like any other engine, the more often you hammer and rev high, the more stress your applying to the engine. Are you going to do it anyway, hell yeah, we all are. Will it shorten it's life, yes most likely. How much? That probably depends on how smart you are about driving it hard. Here are a few suggestions to drive it as we all want to while still having some hope that it will last a while. First off, never drive it hard, like over 3500 rpm's until the engine is fully warmed up. I won't hammer mine until I've driven aboout 8 miles in warm weather and say 12 miles in cold weather. Secondly, keep the oil clean and use a quality oil. Synthetics are your best bet if you can afford it. I've been using Mobil 1 and changing it every 5000 miles or 4 Months, which ever comes first. Watch out for mis-shifts and over-rev's, they can be quite bad. These are just my suggestions. I think most would agree that these are pretty reasonable suggestions. Do I drive mine hard? Oh yeah, 20 track events or so each year, where the engine is in the high rpm's 70 percent of the time. I do short shift at 6k rpm,s 70 percent of the time, just to baby it a bit. I know quite a few guys who have put probably around 80 to 100 track days on there e36's without any problems. It a good strong engine. Play it safe on the street -take it to the track.

[deilenberger]

Hey guys. Recently i've been pushing the car really hard everytime i drive it. Basically going up to 6000/rpm on first and second... at least 7 or 8 times a day... just flooring the thing. Damn its really really fun but i'm thinking maybe its probably gonna stress out the engine pretty badly. How do you guys drive? and do you think its really bad for the car or am i just thinking too much?Well.. you just heard a lot of interesting Internet myths...


Gunk and carbon? Not likely with modern gasolines, and very unlikely unless you are lugging the engine (driving it at too low an RPM) - so that's a non-issue.


Not driven hard bad for the engine? Wrong. Driven normally the engine will be just fine.


If you think about it - engine wear is pretty simple - more RPM's = more wear since the mechanical components are moving/rubbing faster. You got some good advice on maintaining the engine for long life - and I'll pass on some more (which you can accept or just figure on more Internet BS..)

Abuse is different than spirited driving. Sprited driving may on occassion take engine RPMs to or near red-line. Abuse is running along bouncing the engine off the rev limiter. Spirited driving may involve fast shifts at optimal shift points (which is NOT usually max RPM) in each gear. Abuse is dumping the clutch in the next gear while holding the engine against the rev limiter.

I see lots of posts here that are about problems I'd consider symptoms of abuse of the car:


Radiator failures - I suspect most of them are caused by "launches" of the car or dumping the clutch at high RPMs. The failure mode is consistant with engine movement that stresses the upper radiator hose. The engine movement is probably caused by the shock load of clutch-dumps or bad engine mounts - or both.


Cooling fan blades coming off - same scenerio. The only way I can see this happening is if the fan blades hit the fan shroud due to engine movement. The only way I see engine movement happening to that degree is by forces beyond the design limits being put on the engine mounts, ie - dumps/launches.


Differential forward mounting bolt - same thing. The force of a clutch dump or launch is going to try to make the differential rotate around the axles. What is there to stop the rotation from happening? That bolt. What happens if a bolt is over-stressed too many times - it breaks.

As others have suggested - keeping your oil reasonably clean (changing it every 6,000 miles with a good synthetic) is a good thing. Not bouncing off the rev-limiter is a good thing. Not dumping the clutch is a good thing.

Treated well - the S52 engine probably has a projected rebuild life of well in excess of 150,000-200,000 miles. Abused - lots less.

Long - sorry - but you asked.. :cool

[BrandonM3]

^^^^^:buttrock

[hinzm3]

there are people that are using their stock motors as race motors and already have around 15k track miles on a 100k motor.......
Keep your maintenance up, wait for temps to be at an acceptable level before you take the motor into high rpms and you'll be fine.

[jasonknezo]

we just pulled apart an s50 for an e30 swap at 147k and it still has the hatch markings on the cylinder walls-!!!!! my s52 has 90k on it and i just had it compression and leakdown tested and it was the same as it was at 40k! properly warmed up and properly maintained with the right engine oils and weights and 200k isnt out of the ordinary. The highest mileage m3 i have ever seen is a 95 daytona violet at the shop i take my car to here in west chester with 255k on it and it was just in for an oil change, tune up, and a clutch-the first clutch.

[JETninja]

Just note on pre 10/95 Build Date M3's (like mine) you'll want to watch how many times you go to redline. The valve retainers are suspect and prone to failure at some point. At what point I don't know. I've not bumped th limiter yet, I'm pretty careful and I tend to shift more by feel anyways....

[xjeeper]

redline mine almost daily for the past 4 years.

[PALELLA]

redline mine almost daily for the past 4 years.


Me too!! I intentionally beat on it because I know it can handle it.

[PrestoMB]

As said before just let the motor warm up, then you can drive it "spiritedly":evil2 . Question for guys with extra gauges- At what temp is the car at when warmed up? water? oil?

[Vbp6us]

Engine temp does not mean oil temp.

[danp412]

Just note on pre 10/95 Build Date M3's (like mine) you'll want to watch how many times you go to redline. The valve retainers are suspect and prone to failure at some point. At what point I don't know. I've not bumped th limiter yet, I'm pretty careful and I tend to shift more by feel anyways....


Im pretty sure its more like pre 10/94 build date. I think the 95 M3's with the tilt steering wheel are the earlier production models, and those are the ones with the retainer problems.

[macavant]

Make sure the engine (oil) is fully warmed up.
The KEY is your OIL temperature - My coolant temperature gage is at the middle within 10 minutes, but OIL needs at least 15-20 minutes if not more - with outside temperatures around 0 celzius now.
+1 on driving hard @ the right temperature.
besides, I wouldn't want my car "adapting" to a less agressive driving style :)

[Verruckt]

To be honest, I've seen FAR more issues with bimmers that aren't driven hard compared to ones that are.

Carbon buildup is a huge issue in these cars and your car is made to be driven very very hard, so treat it as such.

[bloxsom]

hey my car has 235,000 miles on the same motor and i drive threw the empty vally for about 1-2 hour's in third with the tack at 5,000-6,0000 rpm.
the temp guage dosent move and the car just loves to scream!!
just take care of the oil, and yea....

[methodryder]

I'd like to take a moment to throw in my two cents on the whole topic of engine life, maintenence and abuse. I used to be one of those annoying guys (i might still be annoying, but i belong to a different catagory of annoying now)...but when I say annoying, I mean the guys that buy a nice performance car, polish it up, throw a bunch of mods on it, polish it some more and then drive around carefully, always worrying about the next big bump I was going to hit or the next part that might break down...in any case, no matter what vehicle I ever bought, drove or modded, I just never really had any fun...why, you might ask??? Because I was always worried about damaging or breaking something...well you might get 200,000 miles out of your motor driving it with a limp wrist, but you're going to put 0 miles on with a smile on your face. Change your oil, fix stuff when it breaks down and do that preventative maintenence that makes sense and has to be done...but other than that...drive the hell outta it...now I dont mean head out there and be wreckless...but have some fun and forget about worrying about that next big part that might go bye bye next week...drive it how you wanna drive it and it wont hurt so much when something does break down because no matter how careful and half assed you drive, something's gonna break anyways. Might as well get your money's worth...lol

[NLR]

I drive my car very hard and have owned it for 3 years. It somehow puts down more power than it should (for the mods I have) and compression test I got very good very high psi results (220-225)!

Driving the car hard blows the buildup of carbon and other gunk out of the engine.

Those compression #'s seem rather high for a 328. Even if it were an S52 engine, it would still be high. I'm pretty sure M3 engines have higher compression than the standard 3 series ones. Higher doesn't always mean better. Carbon buildup in the combustion chamber can give you excessively high readings.

[bimbum]

ok, I drove it hard tonight and the radiator gave up the ghost. yay for crappy radiator design!

LOL

ps. the car has only 48k fwiw and no I was not clutch dropping it, no need to do BMW axle testing at night in the rain :P

[BMWManiac]

As said before just let the motor warm up, then you can drive it "spiritedly":evil2 . Question for guys with extra gauges- At what temp is the car at when warmed up? water? oil?

180 oil, 210 water for me

[WytLytnyn]

I drove mine like a wuss the first six months I had it. I could count on one hand how many times I took it above 4500 rpms for fear of damaging something. Having come from a Jeep where all of your torque is down low in the rpm range and never having owned a high performance car, I continued to drive the car around town in the 2K range and short shifted on the highway.

As time went on, I noticed that the motor kind of sputtered when warming up and sometimes stalled in cold weather. When I took it to the shop that I religiously have do my work, the owner chastized me for not driving it harder and told me to take it near redline everytime I hit a highway entrance ramp. I remember him saying that it was "meant to be driven 150mph" everyday.:buttrock :buttrock :buttrock

They did a carbon cleaning on the motor and I started really laying into it on a regular basis which the motor became super smooth, especially after a hard day's mountain run. I also noticed that my mileage increased slightly as well on the highway. Now the motor "lives" above 3K rpms most of the time.

I've also noticed that when I go out of town for a week or two, the motor kind of stumbles a bit at first when warming up. After a good highway run (several trips to 6000rpms before upshifting), its gets right back in the groove. A friend of mine also has experienced this (and applied the same remedy) with his Dinan E39 M5.

I also agree with the regular oil change intervals noted in this discussion regardless of what type of oil you run. Also check the dipstick regularly and keep your oil filled near the top mark on the dipstick.

[JETninja]

Im pretty sure its more like pre 10/94 build date. I think the 95 M3's with the tilt steering wheel are the earlier production models, and those are the ones with the retainer problems.

Nope, 10/'95. Been covered in here many times. I wish Pre- 10/'94....my car is a 10/'94. :D

[GGray]

I am the epitomie of driving it hard...I have driven every car I have owned the last twenty years HARD, race tracks, autocross, street...I also worked in a shop and have done BMW service work for years on the side. the WORST cars we use to see were the ones the owners babied and drove like grandma. One of my mechanic buddies use to tell me to go give it an "italian tune up" AKA: run the donky shit out of it a few minutes to clean the carbon out....Worked every time...I have had motors apart that were "taken care of" aka: Not driven hard...They looked like the carbon monster took a dump in them horrible looking...The motors that I have pulled apart, including mine, that were driven. Clean.

You can get carbon with modern fuel, fuel has nothing to do with it. Its the lack of high rpm and heat that cause the deposits.

And as far as breaking radiators from abuse..thats a good one...The plastic in the radiators of MOST german cars are recyceld. Per the German governments requirment that auto manufacture's use a percentage of recycled plastic in their cars. AKA radiators, plastic body panels etc...Same with the breaking fan blades.

So go drive the piss out of your car and enjoy it for what it was build to do.
And keep your maintance up to date.

[MasterM3]

has anyone else noticed that M3cowboy has been posting some really inane threads lately?

[deilenberger]

ok, I drove it hard tonight and the radiator gave up the ghost. yay for crappy radiator design!

LOL

ps. the car has only 48k fwiw and no I was not clutch dropping it, no need to do BMW axle testing at night in the rain :Pit isn't necessarily going to happen exactly at the time you are doing a "clutch drop" - the effect is cumulative - repeated stressing of the same component will tend to weaken it over time.

Example - E39 BMWs - the V8 series is imfamous for having the same problem the M3 has with radiators - it eats/cracks the upper hose fitting. The I6 engined cars - the problem is unknown. The different - the V8 makes LOTS more torque, which causes more twisting action on the engine... which bends the upper radiator fitting every time you get on it.

The last design for the E39 radiator uses an interesting design - it has a pivot point in the upper hose fitting where it meets the radiator tank, which allows the fitting to move without bending.

I suspect new engine mounts would be a worthwhile investment for anyone who has had a radiator go out on them - and just a FWIW - I think the Nissens design (which does not have grooves in the radiator neck) is a better design - stronger.

[deilenberger]

Blah-blah snipped..


I have had motors apart that were "taken care of" aka: Not driven hard...They looked like the carbon monster took a dump in them horrible looking...The motors that I have pulled apart, including mine, that were driven. Clean.

You can get carbon with modern fuel, fuel has nothing to do with it. Its the lack of high rpm and heat that cause the deposits.
Do you have any data to back up this claim? I'm sure BMW and most gasoline companies would be surprised at this.. BMW used to have a problem with carbon buildup on the intake valves - they came up with a specification for gasoline that would avoid this. ALL modern gasolines sold in the US now meet the BMW specifications. Carbon is not a problem with BMW engines driven "normally"..

And explain how running an engine hard lowers the "heat"... I'd like to hear that one..


And as far as breaking radiators from abuse..thats a good one...The plastic in the radiators of MOST german cars are recyceld. Per the German governments requirment that auto manufacture's use a percentage of recycled plastic in their cars. AKA radiators, plastic body panels etc...Same with the breaking fan blades.
Do you have data on the use of recycled plastics in BMWs?

Last I saw from BMW on the topic - the dashboards on the newer cars (starting with the E39 series) are recycled, the bumpers are made TO be recycled, but no mention is made of engine or cooling components.

It sounds as if you don't understand the concept of repetitive stress failure (same thing that causes airplane wings to fall off once in a while..).


So go drive the piss out of your car and enjoy it for what it was build to do.
And keep your maintance up to date.

Whatever - YMMV and do whatever you want. I certainly wouldn't want to buy a car that had been driven that way.

[m3cowboy]

has anyone else noticed that M3cowboy has been posting some really inane threads lately?


Uhh no.. but if so, why u reading it??

[m3ntalmn]

deilenberger: carbon buildup in modern gasoline engines is still an issue, especially in bmw's. if i could hook up a camera to the boroscope i used today to look at a 540 combustion chamber you would immediatley retract your statement. carbon buildup may not be a problem under continually optimal conditions but how often are running conditions optimal. gasoline quality is a factor but it is most certainly not the only factor affecting carbon buildup. what about cold start injector pulse-width, spark timing and temperature, fuel pressure, intake air temp, ambient temp. engine oil and coolant temp. fortunately for most an "italian tune-up" is the cure if the carbon buildup isn't too severe. but don't take my word for it, i just fix them for a living.

[Roadwarrior1956]

Every car and bike I have had, saw redline everyday I drove them and they all worked great or are working great with no ill affects.

Let the dog EAT!

[Ohtwo]

Italian tune ups are great. They usually work best in the higher gears, especialy when going up hills.

Before I had my car in good tune, it required constant italian tune ups to keep the plugs and combustion chamber clean. Lugging is said to be hard on the bottom end of the engine.

Where can I get a boro scope, and how much do they cost?

[m3ntalmn]

any major tool manufacturer should have them. around $300. sorry it is a borescope i spelled it wrong

[deilenberger]

deilenberger: carbon buildup in modern gasoline engines is still an issue, especially in bmw's. if i could hook up a camera to the boroscope i used today to look at a 540 combustion chamber you would immediatley retract your statement. carbon buildup may not be a problem under continually optimal conditions but how often are running conditions optimal. gasoline quality is a factor but it is most certainly not the only factor affecting carbon buildup. what about cold start injector pulse-width, spark timing and temperature, fuel pressure, intake air temp, ambient temp. engine oil and coolant temp. fortunately for most an "italian tune-up" is the cure if the carbon buildup isn't too severe. but don't take my word for it, i just fix them for a living.I can believe you will have some carbon buildup - (I take a lot more BMW bikes apart than the cars - the cars never need it..) - but it has to be severe before it causes problems (raising compression or causing localized pinging..) A certain amount of carbon on top of the pistons is considered normal.

The carbon problems BMW *used* to have were on the intake valves - the backside of the intake valves. They would get coatings of carbon on them 1/2" thick. This obviously caused problems since the carbon would become gasoline saturated and upset the mixture, plus it restricted intake flow. Getting a BMW to idle decent was a real challenge when that was a problem.

What BMW did is several fold:

1. Came up with ways of removing the carbon on the valves - the infamous walnut shell blaster was given to the dealers to tackle bad cases.. Not so bad cases were dosed with something like Techron or BG44(?). The goal being to get clean valve backs.

2. Revised the injector tips so they didn't coke up (carbon up) which made the spray uneven and contributed to the valve-carbon problem.

3. Made their own gasoline specification, and tested all the major brands - and issued the results. This was very effective - since all FI cars of the era were having driveability problems - the "BMW spec" became the standard, and the fuel companies quickly hussled to met the spec.

Point being - carbon is no longer the major cause of bad running that it used to be. Can you have a carbon problem? I guess in the case of a 2-mile railroad station commuter car - sure - it never gets hot enough to run at a normal mixture so you will have some carboning up. Will the average car owned by people here have a carbon problem? I think not.. I've only owned about 10 BMW's now - some back when carbon was a problem, and I took care of it with Techron. I have had no carbon problems (indeed - NO engine problems at all) on any of the post 1991 BMW's I've owned (which is probably about 600,000 miles on them now) - and some have had well over 100k miles on them when I sold them.

BTW - there are camera's that can be used with a boroscope - you might even try sticking your digital one up to the eyepiece..

BTW-II - as a mechanic - you should remember - you see the problem cars. You don't really see cars that are running perfectly - except for normal maintenance issues. It tends to skew your view..

[bimmerdriver99]

I drive mine hard pretty much everywhere, even to get groceries. :) But I do make sure I give it plenty of time to warm up.

PS: Im looking to get some gauges this spring, most likely the 3 ones that goes right where the sunglass holder is. What are some good recommendations. I like the angle ones that Mpact sells, any other suggestions are welcome.

[MasterM3]

Uhh no.. but if so, why u reading it??

it's a public forum. thats why. you got anymore stupid questions to ask? if so, feel free to start a new thread!:rolleyes

[mobil1]

WOW, my god that guy was right. It is the same person starting all these useless threads.

[Verruckt]

I can believe you will have some carbon buildup - (I take a lot more BMW bikes apart than the cars - the cars never need it..) - but it has to be severe before it causes problems (raising compression or causing localized pinging..) A certain amount of carbon on top of the pistons is considered normal.

The carbon problems BMW *used* to have were on the intake valves - the backside of the intake valves. They would get coatings of carbon on them 1/2" thick. This obviously caused problems since the carbon would become gasoline saturated and upset the mixture, plus it restricted intake flow. Getting a BMW to idle decent was a real challenge when that was a problem.

What BMW did is several fold:

1. Came up with ways of removing the carbon on the valves - the infamous walnut shell blaster was given to the dealers to tackle bad cases.. Not so bad cases were dosed with something like Techron or BG44(?). The goal being to get clean valve backs.

2. Revised the injector tips so they didn't coke up (carbon up) which made the spray uneven and contributed to the valve-carbon problem.

3. Made their own gasoline specification, and tested all the major brands - and issued the results. This was very effective - since all FI cars of the era were having driveability problems - the "BMW spec" became the standard, and the fuel companies quickly hussled to met the spec.

Point being - carbon is no longer the major cause of bad running that it used to be. Can you have a carbon problem? I guess in the case of a 2-mile railroad station commuter car - sure - it never gets hot enough to run at a normal mixture so you will have some carboning up. Will the average car owned by people here have a carbon problem? I think not.. I've only owned about 10 BMW's now - some back when carbon was a problem, and I took care of it with Techron. I have had no carbon problems (indeed - NO engine problems at all) on any of the post 1991 BMW's I've owned (which is probably about 600,000 miles on them now) - and some have had well over 100k miles on them when I sold them.

BTW - there are camera's that can be used with a boroscope - you might even try sticking your digital one up to the eyepiece..

BTW-II - as a mechanic - you should remember - you see the problem cars. You don't really see cars that are running perfectly - except for normal maintenance issues. It tends to skew your view..


You sir are WRONG.

The carbon buildup is still an issue on E39s (especially M5s), E53s, and pretty much most BMW V8s. Also it is not on the intake valves but on the exhaust valves, and has to do with emissions and can be very very serious. As we speak my shop has the heads off of one right now being cleaned like crazy. It's actually so common that BMW has a special tool kit to clean these and it is a well known procedure.

I can tell you, cars driven at lower RPMs, and for less time get FAR more buildup than cars driven hard.

I don't know where you seem to get your information but you need to get some cold hard facts before making such statements.

[BrandonM3]

WOW, my god that guy was right. It is the same person starting all these useless threads.

Hey now, this thread can't be that useless if it's getting this much attention; plus, you seem to be reading and following along too. Who cares if someone posts, what you may think to be, a useless thread. If you don't like it, don't read it, there are plenty of other threads for you to give your input on. Let's just settle down now eh? :)

[Trackout]

Actually I think it's a pretty useful thread for those not in the know. I have a pretty good idea how to drive hard while still protecting my engine now, but I didn't 30 years ago when I was a young pup driving my first few hot rods.

[deilenberger]

You sir are WRONG.

The carbon buildup is still an issue on E39s (especially M5s), E53s, and pretty much most BMW V8s. Also it is not on the intake valves but on the exhaust valves, and has to do with emissions and can be very very serious. As we speak my shop has the heads off of one right now being cleaned like crazy. It's actually so common that BMW has a special tool kit to clean these and it is a well known procedure.

I can tell you, cars driven at lower RPMs, and for less time get FAR more buildup than cars driven hard.

I don't know where you seem to get your information but you need to get some cold hard facts before making such statements.
Interesting.

I run a group for the E39 series on Yahoo.

Currently we have over 1,300 members from all over the world, and lots of models that never made it here to the USA.

With a group that size - common problems quickly become known. Failing cat converters on the V8's, radiators on the V8's, leaking valve cover gaskets on the V8 - all are known problems that have occurred to a number of E39 cars owned by members of the group.

What I have not seen - and the group has been in existence for over 4 years now - is a SINGLE instance of a carbon buildup problem.

Not one. Nada. Zilch.

Please reference the BMW SI# that covers the topic - I have some access to the on-line TIS service and I'd like to read it (if there is a special tool - there should be a SI referring to it.)

There is an old saying - If someone has a hammer most things look like a nail.

Not that I doubt that you've seen this problem - but it is an unusual one based on my experience with 1,300 E39 owners. A goodly number of my Yahoo group have M5's (a surprising number to me actually) and a goodly number have the V8 540 series (and a few euro 535i V8's).

If it is a "common" problem - it seems to be bypassing all these people which I find unlikely.

As you may know (or not) - a mailing list, newsgroup, forum or Yahoo group tends to be a "concentrator" of problems. People don't write to tell everyone they are NOT having problems with say carbon buildup on exhaust valves. People will write when they do have a problem. The number of people in the group having the problem may be low - but the appearance of the problem will seem high unless you consider all the people who haven't bothered to say they hadn't experienced the problem. It's the same problem any tech person has - falling into the "they all do that" syndrome once you see enough of the same problem. Thing is - you're not seeing the ones that don't have the problem so the view is skewed.

A question - have you seen any correlation with the carbon buildup on the exhaust valves and failed catalytic converters?

I can see a mechanism where increased back pressure due to failing cats could cause carbon buildup on exhaust valves. I actually can't see any other way this could happen if the DME feedback (O2 sensors/mixture) is working properly.

If this is the case - the problem isn't fuel related, it isn't mixture related - it is back pressure related and caused by the cat converters. And using something like Techron is unlikely to have much effect on it at all.

BTW - if you'd like to join the E39 group - and search the archives (we have a wonderful tool made by one of the members that does an excellent job for searching) the URL is:

http://autos.groups.yahoo.com/group/bmwe39/

When you go to subscribe - just reference this message in the M3 forum and I'll approve you for membership (membership is by approval only..) I always welcome tech expertise to the group (and there are a surprising number of very well known tech-savy people who are members..)

Meanwhile, I'll copy a bit of your message (removing your name of course) to my group and see if anyone has ever experienced a carbon buildup problem on their V8 engine. I'll pass back the answer if anyone has..

[mobil1]

Hey now, this thread can't be that useless if it's getting this much attention; plus, you seem to be reading and following along too. Who cares if someone posts, what you may think to be, a useless thread. If you don't like it, don't read it, there are plenty of other threads for you to give your input on. Let's just settle down now eh? :)


It gets a lot of attention because everyone can post an opinion on the topic. Im surprised any of the techs are even posting.

Everyone drives their M3's hard. If not, then why did you buy it? Cause its pretty to look at? Waste of money imo.

If you wanted to drive slow, any car will do. If you really liked the e36 models, then save a bundle on insurance and cost by going to a 328.

I noticed someone touched on the carbon build up...It does say a few things in the owners manual about letting the car idle for too long and getting carbon build up that way, not by driving it slow. However, I think I recall some older porsches suffering from carbon build up..that and having to tweak the cams all the time. Anyways, good times.

[Verruckt]

Meh won't quote all that but,

I can find the SIB # tommorow and get back to you via PM on that.

[MasterM3]

I'm calling this thread inane simply because the questions posted by M3cowboy are so ridiculously stupid that I'm suprised people contribute their opinions.

Read what he is asking one more time. Can you answer his questions? I for one have no idea how long his engine is going to last, and I really can't say whether or not redlining his car is "bad" for it. I don't know if he performs all the maintinence regularly, I don't know whether he tracks his car at all of if he just daily drives it, etc etc.

How do I drive? I drive pretty normally, usually letting off the gas, engaging the clutch and shifting sequentially. But if you wanna know a secret and promise you won't tell ANNYONE, sometimes I skip gears. Gasp! Yes I do mean 3-5.

Seriously, WTF kind of post is this? lol Why not ask this questions first before the thread becomes an argument on carbon buildup? Either that, or we need a new forum for all the newbs to ask their basic questions. I think this thread would fit nicely with "difference between coupe/sedan", "obdI v. obdII", and "what are the best mods for my M3" threads.

[deilenberger]

Meh won't quote all that but,

I can find the SIB # tommorow and get back to you via PM on that.As I mentioned - I asked my E39 Yahoo group, and one person did get back to me with a link to a carbon buildup problem in the E39 M5 series. It seemed (from the thread) to be limited to 2000-2001 model year, and there weren't a lot of reports of the problem.

It also seemed BMW was a bit baffled as to the cause - since it didn't happen on euro cars (if this sounds familiar - think of the Nikasil engine problem with the early V8's, and the carbon problem with the M30 series engines..) They apparently are covering at least some of the costs for some of the people - on a case by case basis.

The carbon problem in question is with the secondary air system - and has no effect on how the car runs - but it does toss a CEL and will be grounds for failing emissions inspection.

Sorry - I wuz wrong - it happens..

Best,

[bmxcm]

Sorry - I wuz wrong - it happens..
Best,
o my, deilenberger is wrong?!? what is this world/forum coming to:help



j/k, happens to the best of us, some more often than not...

[GasNSteering]

There is a section in the M3 manual stating that after being driven in city traffic that the rpm's should be kept over 3k for a period of time. I assume it was to prevent carbon buildup.

[clumpymold]

If you're not gonna drive the car hard, why even buy an M3? :dunno

I drive it like it's stolen. :devillook

[NLR]

There is a section in the M3 manual stating that after being driven in city traffic that the rpm's should be kept over 3k for a period of time. I assume it was to prevent carbon buildup.

I remember reading that also. My question is... what is so different about these engines that this would even be required or recommended? The way the M3 is geared, its practically impossible to not be turning over 3k rpms on the highway anyhow, while alot of other cars are cruising along lazily at 2500 rpms or so and I doubt that they say to run the engine over 3k rpms periodically.

Regardless, I heed the manufacturer's advice. I was just wondering.