Valve seals

DG330 · 09-21-2019, 02:17 PM

Hi,

Anyone had to replace these on their m57 engine?

I'm struggling to track the source of my idle smoke which is constant except when driven, then it comes back quickly. It also is there when I rev the engine at 2/3k etc. just streams out the back.

Anyone ever had to replace their valve seals?

Thanks

Persian Whisperjet · 09-21-2019, 02:46 PM

I have not, but some people have found symptoms similar to yours from a brittle valve cover gasket. Other (less common) possibilities include failing turbos.

DG330 · 09-21-2019, 03:22 PM

Quote:

Originally Posted by Persian Whisperjet

I have not, but some people have found symptoms similar to yours from a brittle valve cover gasket. Other (less common) possibilities include failing turbos.

Replaced both, the rocker cover was a complete pita! It was rock solid and oil was seeping underneath it.

DG330 · 09-21-2019, 03:25 PM

The turbo was a recon, new one has some play, but not much. No in or out.

Valve seals? Would they smoke when revs are incensed and held??

Thecastle · 09-25-2019, 08:42 AM

Tuned?

Generally the test for bad valve stem seals is the following. Get the engine fully warmed up. Then let the car idle at least 5 minutes once fully warmed. Then have a buddy stand out by the tail pipes and floor it.

Smoke screen? Then you probably have bad valve stem seals. If their quite bad they will smoke even at idle.

Also smoking can be from a leaking egr cooler, leaking coolant into the engine. Too much fuel in the exhaust, and oil leaking from various sources.

I’ve yet to hear of an m57 with bad valve stem seals. Happens all the time in bmw v8s. I’ve had them on a n62 4.8i. My current s63 and N63tu are smoke free thus far... knock on wood.

DG330 · 09-25-2019, 12:31 PM

Hi,

Yeah it's had a remap and dpf solution.

Well I get constant smoke. I'll do some logging this weekend coming to work out if unplugging any sensors helps and recoding aim mass etc.

The constant smoke is small puff at start, then a gradual stream of light pale blue until warmed up when it becomes more visible.

Having read about valve seals, it doesn't appear to be as much of an issue on the turbo diesel due to pressure not vacuum inside the crank case. Still looking into understanding it all, but guess it's to do with air being forced vs pulled through on non turbo. However, sure they still go on turbo petrol cars.

09-21-2019, 02:17 PM	#1
DG330 First Lieutenant 70 Rep 360 Posts Drives: 330 Join Date: Nov 2018 Location: Uk iTrader: (0)	Valve seals - do they fail Hi, Anyone had to replace these on their m57 engine? I'm struggling to track the source of my idle smoke which is constant except when driven, then it comes back quickly. It also is there when I rev the engine at 2/3k etc. just streams out the back. Anyone ever had to replace their valve seals? Thanks
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09-21-2019, 02:46 PM	#2
Persian Whisperjet Kind of a Big Deal 167 Rep 857 Posts Drives: 2011 335d Join Date: Dec 2012 Location: Washington, D.C. iTrader: (0)	I have not, but some people have found symptoms similar to yours from a brittle valve cover gasket. Other (less common) possibilities include failing turbos. __________________
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09-21-2019, 03:25 PM	#4
DG330 First Lieutenant 70 Rep 360 Posts Drives: 330 Join Date: Nov 2018 Location: Uk iTrader: (0)	The turbo was a recon, new one has some play, but not much. No in or out. Valve seals? Would they smoke when revs are incensed and held??
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09-25-2019, 08:42 AM	#5
Thecastle Major 307 Rep 1,146 Posts Drives: F10 550i Join Date: Apr 2015 Location: Houston, TX iTrader: (0) Garage List 2020 BMW M340i [0.00] 2019 RAM 3500 [0.00] 2020 BMW X3 [0.00] 2016 BMW 550i [0.00] 2000 Ford F450 7.3l ... [0.00]	Tuned? Generally the test for bad valve stem seals is the following. Get the engine fully warmed up. Then let the car idle at least 5 minutes once fully warmed. Then have a buddy stand out by the tail pipes and floor it. Smoke screen? Then you probably have bad valve stem seals. If their quite bad they will smoke even at idle. Also smoking can be from a leaking egr cooler, leaking coolant into the engine. Too much fuel in the exhaust, and oil leaking from various sources. I’ve yet to hear of an m57 with bad valve stem seals. Happens all the time in bmw v8s. I’ve had them on a n62 4.8i. My current s63 and N63tu are smoke free thus far... knock on wood.
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09-25-2019, 12:31 PM	#6
DG330 First Lieutenant 70 Rep 360 Posts Drives: 330 Join Date: Nov 2018 Location: Uk iTrader: (0)	Blank Hi, Yeah it's had a remap and dpf solution. Well I get constant smoke. I'll do some logging this weekend coming to work out if unplugging any sensors helps and recoding aim mass etc. The constant smoke is small puff at start, then a gradual stream of light pale blue until warmed up when it becomes more visible. Having read about valve seals, it doesn't appear to be as much of an issue on the turbo diesel due to pressure not vacuum inside the crank case. Still looking into understanding it all, but guess it's to do with air being forced vs pulled through on non turbo. However, sure they still go on turbo petrol cars.
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