Cold natured 540...is this normal

[dbals]

I just purchased a 95 540 and it is unbelievably cold natured. When I go out and start it in the morning you have to let it warm up to half way on the temp gage before it will run right......it spits and sputters and then once its warm it runs fine. Is this normal for a 540???? Should I be concerned?
-Drew

[digitaldragon03]

Mine has to warm up a bit too, or else it runs rough. I dont let it warm to half temp though, i just rev it to around 800 for a minute and then leave. The transmission is also slow to shift gear when its cold. My passenger side door wouldnt lock in the mornings either, but that seems to have gone away.

[tim]

Until the o2 sensors warm up and start to signal, the engine runs in sports mode, which is basically rich. Since it's fine once it warms up, I doubt there's a real problem.

Possible solutions are:
*replacing the o2 sensors (perhaps the new ones will warm up faster.)
*checking the AFM Boot carefully for cracks and any possible unmetered air.
while you have it off, spray some carb cleaner or the like onto a clean rag and clean out the inside of the throttle intake and ICV valve.
*Do a reset on the computer by disconnecting the battery and touching the (car, not battery) terminals together for awhile-couldn't hurt and often is all that's needed.
*Do an Italian tune up by getting some techron, running in the last 2 gallons of gas in the tank, and then drive it hard! After, change the oil.

P.S., mine runs like **** too until it warms up.

[digitaldragon03]

Haha, the slow shifting reminded me of sports mode and up until now i didnt know it really was sports mode.

[SharkmanBMW]

Mine ran rough before warmup until I fixed the PCV plate... common V8 problem.
Once fixed it is perfect,
you guys with rough idle while cold... it is NOT normal, doing the PCV plate on back of intake manifold should fix you up.

If it was an air leak somewhere, would it not be rough after warmup as well?

Be careful doing the reset, it is NOT the battery terminals you touch, but the car's terminals :p

[dbals]

Mine ran rough before warmup until I fixed the PCV plate... common V8 problem.
Once fixed it is perfect,
you guys with rough idle while cold... it is NOT normal, doing the PCV plate on back of intake manifold should fix you up.

If it was an air leak somewhere, would it not be rough after warmup as well?

Be careful doing the reset, it is NOT the battery terminals you touch, but the car's terminals :p
Ok....help me out. Whats a PCV plate and whats it do? And could you clarify the reset process. My car does have an ESS S/C kit on it with different mass air flow and injectors.......

[tim]

Good point about the terminals sharky- I edited the post.

I think you're right about the pcv too. I'll give you $50 if you come and do mine. I find that job to be a real pain, so I'm waiting for a few good excuses to take the intake manifold off and do it right.

Also, as regards unmetered air. The car is most sensitive to it at low throttle, and especially before the o2 loop starts firing. At higher throttles, the o2 sensors detect the lean condition from the exhaust and compensate by increasing lambda to full rich. At low rpm's they get confused and the lambda jumps around. When cold, you're running super rich anyway, but a leak in the boot can mess around with the icv valve- But you're right, it would basically be the same problem before or after warm up.


Mine ran rough before warmup until I fixed the PCV plate... common V8 problem.
Once fixed it is perfect,
you guys with rough idle while cold... it is NOT normal, doing the PCV plate on back of intake manifold should fix you up.

If it was an air leak somewhere, would it not be rough after warmup as well?

Be careful doing the reset, it is NOT the battery terminals you touch, but the car's terminals :p

[SharkmanBMW]

Tim,
You are on your own with the PCV plate!
I paid my indy a ton of loot to do mine... No access for my clumsy hands!

But I promise you it's worth the time and/or $$$!!!

[dbals]

Tim,
You are on your own with the PCV plate!
I paid my indy a ton of loot to do mine... No access for my clumsy hands!

But I promise you it's worth the time and/or $$$!!!
Please explain what this does and what it is.....call me stupid, just trying to learn.....
thx

[tim]

Definition:
The Positive Crankcase Ventilation valve is a device that routes unburned crankcase blowby gases back into the intake manifold where they can be reburned. The constant recirculation of air through the crankcase helps remove moisture which otherwise would cause sludge to form. Thus the PCV valve extends the life of the oil and engine. The PCV valve requires no maintenance. Eventually it will gum up and cease to function properly. When it does it often messes with the vacuum pressure and creates other hard to isolate glitches in idling, and with the o2 sensors as well. On the old ones from both america and germany, you could just soak it in gas awhile, but the BMW ones on the m60 are more or less sealed elements.

The location is directly under the coolant reservoir, on the back of the block, under the coolant pipes, right where you can't get to it or see it, unless you take off the intake manifold/fuel rail assembly. Let's face it though, the m60 is a big badass, in a pretty tight space, so you can't expect everything to be right where you can get at it.

The reset process is not an official deal, but was discovered by one our own here on the board. Many of the computer engine control elements like the adaptive shifting on the automatic use a stored charge in an eeprom chip to control threir values. A quick way to make sure that all values are being reset, is by holding the car's battery leads together for awhile (not shorting a live battery of course!). Then when you start up again you put in your radio code and reset the clock and you're back to square one as far as the motronic is concerned.


Please explain what this does and what it is.....call me stupid, just trying to learn.....
thx

[SharkmanBMW]

Definition:
The Positive Crankcase Ventilation valve is a device that routes unburned crankcase blowby gases back into the intake manifold where they can be reburned. The constant recirculation of air through the crankcase helps remove moisture which otherwise would cause sludge to form. Thus the PCV valve extends the life of the oil and engine. The PCV valve requires no maintenance. Eventually it will gum up and cease to function properly. When it does it often messes with the vacuum pressure and creates other hard to isolate glitches in idling, and with the o2 sensors as well. On the old ones from both america and germany, you could just soak it in gas awhile, but the BMW ones on the m60 are more or less sealed elements.

The location is directly under the coolant reservoir, on the back of the block, under the coolant pipes, right where you can't get to it or see it, unless you take off the intake manifold/fuel rail assembly. Let's face it though, the m60 is a big badass, in a pretty tight space, so you can't expect everything to be right where you can get at it.

The reset process is not an official deal, but was discovered by one our own here on the board. Many of the computer engine control elements like the adaptive shifting on the automatic use a stored charge in an eeprom chip to control threir values. A quick way to make sure that all values are being reset, is by holding the car's battery leads together for awhile (not shorting a live battery of course!). Then when you start up again you put in your radio code and reset the clock and you're back to square one as far as the motronic is concerned.


when you do the reset, key has to be in position 2 i believe, and car's terminals, not battery's!!!

[infinity5]

I think they derseve what happens if they think resetting the car involves touching battery leads together ;)

[632 Regal]

I doubt the battery would be much good after that game!


I think they derseve what happens if they think resetting the car involves touching battery leads together ;)

[632 Regal]

The pcv is part of the potential problem, the V8 engines also tend to require new intake gaskets time to time and when the weather turns colder you will see a butt load of V8 owners having problems.

The job isnt very hard with some mechanical experience but might be a challance for someone with little mechanical experience.

Definetly check all tubing and hoses in the intake system before tearing it down.

I did the pcv and intake gaskets (going real slow and cautious cause the intake slipped a bugle) in about 3.5 hours...eastern standard time.

lol


Ok....help me out. Whats a PCV plate and whats it do? And could you clarify the reset process. My car does have an ESS S/C kit on it with different mass air flow and injectors.......

[dbals]

Thanks guys on the education. So does the problem I am describing sound like the PCV plate to you? Does any one have a write up on what eactly needs to be done to fix it?
thx

[632 Regal]

remove the old one from the back of the intake and bolt the new one on. Still think you should do the intake gaskets, I mean you will sooner or later and winters coming soon.

[MBXB]

dbals,
Sent you an email with some pics. If you do a search with 'M60' and 'PCV" you'll pull up several threads on that cover the PCV/Cyclonic valve(that's what the stealer called it).

[540Dave]

After reading this thread I went out to the driveway to look at my intake boot and elbow for cracks etc. I also checked clamps with a screwdriver. One was loose. I suspect that once we go through a significant temp. change the metal intake elbow must contract more than to boot did as I never had this problem in warm weather. Once the engine warmed up it must have been just enough to take up the slack either by affecting the boot or the elbow....who knows. Believe it or not, a quick tightening of the clamp at the elbow smoothed out my cold idle and so far I have had no return of the dreaded 'check engine' light. At least for now!

[motuman]

Mine ran rough before warmup until I fixed the PCV plate... common V8 problem.
Once fixed it is perfect,
you guys with rough idle while cold... it is NOT normal, doing the PCV plate on back of intake manifold should fix you up. :p

I have had (2) 540's and they both run perfect when cold. I honestly can't tell any difference between hot and cold. Of course I have never pushed it till it warms up, but the idle and low rpm driving are the same.

[winfred]

the intake manifold gaskets and throttle body gasket can leak when the motor is cold but seal up as the motor warms up, fun to diagnose if you don't know what to look for. and the pcv plate is a major issue

[mattyb]

damn eh! I just get in mine and go, no probs ever. warm up for 2 secs, gentle for 5 mins then 150km/h for 2 hours no worries.