Friend has a older BMW 7 series with the V8. He notices a puff of white smoke only on start up. He is using synthetic oil in this car with high miles. He asked if 'blue smoke' means oil burning does 'white smoke' mean synthetic oil burning? I said it could mean coolant is getting into the cylinders and burning. However a puff of smoke on start up generally means the valve stem seals are worn and leaking oil into the cylinders and burning. What does white smoke on start up indicate?
BMW 7 series puff of white smoke only at start up?
- Thread starter Jim Spahr
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I would not try and guess what is wrong with an engine just from the colour of the smoke. With an older engine there might be both a small coolant leak, a broken ring and a dodgy injector causing fluids to enter the cylinder and the resulting smoke colour will not indicate the cause.
Best idea is to get a compression check done and/or send off a used engine oil sample to a fast lab like Blackstones. It will show up if the rings or valves are bad and will identify coolant leaks in addition to fuel injector trouble.
What does the oil on the dipstick look like?? If there is any trace of a non black colour like brown if the oil is old, then stop using the car until you get it sorted, because by the time you notice a dubious oil colour, you are already damaging the engine in a big way. If the UOA is good then it might be a turbo seal leak, although I would guess bad valve guides, rings or a coolant leak.
Best idea is to get a compression check done and/or send off a used engine oil sample to a fast lab like Blackstones. It will show up if the rings or valves are bad and will identify coolant leaks in addition to fuel injector trouble.
What does the oil on the dipstick look like?? If there is any trace of a non black colour like brown if the oil is old, then stop using the car until you get it sorted, because by the time you notice a dubious oil colour, you are already damaging the engine in a big way. If the UOA is good then it might be a turbo seal leak, although I would guess bad valve guides, rings or a coolant leak.
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Is the car short tripped a lot?
When I tried a OCI using PP, I got White smoke on start-ups (and only the oil level was going down). Switching back to VWB caused the smoke to stop...
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I would say 80% short trips and 20% highway miles. I already have an inquiry as to what yr. and model and total miles this & series is. It isn't a turbo on this V8. I see on many new BMW's they have gone to turbo's on smaller engines.
Coolant, pull an oil sample and report back.
If it wasn't for the color mentioned, bad valve seals would be the problem. Ask your friend if its really white, or light blue.
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Originally Posted By: Jim Spahr
I would say 80% short trips and 20% highway miles. I already have an inquiry as to what yr. and model and total miles this & series is. It isn't a turbo on this V8. I see on many new BMW's they have gone to turbo's on smaller engines.
The 80% short trips could simply mean condensation in the exhaust system as well.
I would say 80% short trips and 20% highway miles. I already have an inquiry as to what yr. and model and total miles this & series is. It isn't a turbo on this V8. I see on many new BMW's they have gone to turbo's on smaller engines.
The 80% short trips could simply mean condensation in the exhaust system as well.
My friend drives a 2001, 740iL, with 139k miles on it. Uses synthetic oil.
No, he is not the original owner of the BMW.
With no coolant loss, it is probably valve guides/seals.
Maybe normal water that is not hot enough to turn to gas when at normal operating temps.
Maybe normal water that is not hot enough to turn to gas when at normal operating temps.
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Originally Posted By: Jim Spahr
My friend drives a 2001, 740iL, with 139k miles on it. Uses synthetic oil.
What oil? Should be the BMW 5w30, GC 0w30, M1 0w40...etc.
The M62 isn't known for head gasket issues AFAIK, but it does have a huge honkin' resonator and large mufflers which could accumulate moisture from short trips and lead to water vapour on start-up.
It is essentially a less high-strung version of the S62 in the E39 M5.
My friend drives a 2001, 740iL, with 139k miles on it. Uses synthetic oil.
What oil? Should be the BMW 5w30, GC 0w30, M1 0w40...etc.
The M62 isn't known for head gasket issues AFAIK, but it does have a huge honkin' resonator and large mufflers which could accumulate moisture from short trips and lead to water vapour on start-up.
It is essentially a less high-strung version of the S62 in the E39 M5.
It depends on WHEN... see the smoke at actual ignition? Then it's usually oil.
Need to wait a few minutes? Figure moisture.
If that engine has very many miles it'll have a ton of oil and residues in the intake manifold. This can mimic valve seal issues.
Don't be fooled.
Need to wait a few minutes? Figure moisture.
If that engine has very many miles it'll have a ton of oil and residues in the intake manifold. This can mimic valve seal issues.
Don't be fooled.
OP says: My friend this morning took his BMW 740iL to an independent shop and the mechanic says he thinks it is a bad PCV valve. I was thinking -for my GM cars $10-12 for the part and labor--maybe one half hour. Maybe $50.00? The mechanic says many with this engine have had oil burning problems and taken it to a mechanic and were told it would take a new engine for $8,000.00. They would then take it to him and find it was only a sticking PCV valve for $300.00. I am glad it is something simple, but $300 for a PCV R&R sounds high? To continue, the mechanic says the combination of synthetic oil and the bad PCV causes the white smoke in BMW V8's.
More info on this particular car. Oil is Valvoline synthetic: 5w/40 and the OCI is 10k. Wow, that is some PCV valve.
More info on this particular car. Oil is Valvoline synthetic: 5w/40 and the OCI is 10k. Wow, that is some PCV valve.
Originally Posted By: SteveSRT8
It depends on WHEN... see the smoke at actual ignition? Then it's usually oil.
Need to wait a few minutes? Figure moisture.
If that engine has very many miles it'll have a ton of oil and residues in the intake manifold. This can mimic valve seal issues.
Don't be fooled.
Interesting point about oil in the manifold [common], but this would flow and burn all the time, not just at start up.
It depends on WHEN... see the smoke at actual ignition? Then it's usually oil.
Need to wait a few minutes? Figure moisture.
If that engine has very many miles it'll have a ton of oil and residues in the intake manifold. This can mimic valve seal issues.
Don't be fooled.
Interesting point about oil in the manifold [common], but this would flow and burn all the time, not just at start up.
This is most likely oil burning...not a head gasket. The oil is probably coming from either the valve guide seals or the crankcase vent system that the mechanic believes.
Almost all late model BMW v8s share this issue....let car idle for 15 minutes or so, then rev it up a bit...I'll bet it'll blow blue oil smoke for a second or two.
I'd do the vent system overhaul and leave it at that.
Almost all late model BMW v8s share this issue....let car idle for 15 minutes or so, then rev it up a bit...I'll bet it'll blow blue oil smoke for a second or two.
I'd do the vent system overhaul and leave it at that.
I Googled 2001 740iL reliability and wish I hadn't. Summary is they break often and repairs are expensive. Here's one I copied:
These engines are notorious for lower intake leaks that will cause the engine to burn and leak oil and coolant, the oil is usually from the seperator on the back of the intake, which usually gets replaced when the intake gets resealed. also, these engines are notorious for valve cover gasket leaks and front cover leaks. the codes you saw were probably for lean adaptations out of range (too lean) due to the leaking gaskets around the intake. the shaking is due to the air leaks, and possibly if the oil leaks around the spark plugs are bad enough to cause the plugs to misfire..
good luck
These engines are notorious for lower intake leaks that will cause the engine to burn and leak oil and coolant, the oil is usually from the seperator on the back of the intake, which usually gets replaced when the intake gets resealed. also, these engines are notorious for valve cover gasket leaks and front cover leaks. the codes you saw were probably for lean adaptations out of range (too lean) due to the leaking gaskets around the intake. the shaking is due to the air leaks, and possibly if the oil leaks around the spark plugs are bad enough to cause the plugs to misfire..
good luck
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