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

[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

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

[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