Engine: 850 T5/R - Excessive smoke when idle for period of time??

Tension · Nov 9th, 2013, 18:34

Evening folks.

The 95 850 T-5R has a problem where if sat for a while with the engine running, a LOT of smoke will be produced from the exhaust. It is definitely grey smoke, not steam.

The car is drinking oil at an alarming rate also, up to a litre every week or fortnight, sometimes it also feels like the car is down on power.

This smoking stops when normal driving is resumed.

Anybody know what might be causing this? I suspect the turbo, valve stem seals, or piston rings? Not sure how to diagnose further.

As always, any help would be much appreciated.

Thanks very much folks

mikealder · Nov 9th, 2013, 18:40

Pop the oil dipstick with it running, is it puffing smoke out? if so clear the PCV out but pay especial attention to clearing out the lower port in the front of the engine where the PCV tank connects. This is probably blocked so the PCV isn't doing its job and just burning the oil through the exhaust.

Best way to check the lower port is clear is to attach a length of 5/8 rubber hose to the port and try to blow through it, if you can't then it is blocked and needs further work to clear it out - Mike

Tension · Nov 9th, 2013, 18:49

Forgot to mention, did the PCV last year, upgraded the vacuum hose etc, so it's not that.

PS i've noticed over the years that you seem to be the resident PCV expert round these parts

Tension · Nov 9th, 2013, 18:52

The fact that it only happens when idling for a good few minutes made me wonder is it a temperature related problem, but the guage never moves too much, and the coolant levels have always been fine..

mikealder · Nov 9th, 2013, 18:53

Did you blow through the lower PCV port though? - Mike

Tension · Nov 9th, 2013, 19:04

Quote:

Originally Posted by mikealder

Did you blow through the lower PCV port though? - Mike

Yes, it was unblocked.

scvolvo · Nov 9th, 2013, 19:54

Could well be turbo seals? What the movement like on the shaft?

Tension · Nov 9th, 2013, 21:04

Quote:

Originally Posted by scvolvo

Could well be turbo seals? What the movement like on the shaft?

The turbo shaft? Haven't unbolted anything as I'm still using the car every day. Can the turbo even be replaced with the engine in situ? Can seals be replaced or is a whole new turbo required?? Thanks.

brickman · Nov 9th, 2013, 21:13

+1 on turbo seals.

last two petrol turbo car's I've had smoked (oil) at idle and on overrun when warm below 2000rpm. Both were worn turbo oil seals, one turbo I rebuilt with a cheap (£17) ebay chinese rebuild kit and that sorted that, the other the compressor wheel was seriously worn and missing parts so had to source a recon turbo.

But 1st port of call should be breather/PCV system

Tension · Nov 9th, 2013, 21:29

I am 1000% sure it's not the PCV system.

So how does a layman go about replacing the turbo seals?

Is it an 'engine out' job??

Nov 9th, 2013, 18:34	#1
Tension Senior Member Last Online: Mar 22nd, 2015 22:53 Join Date: Jul 2009 Location: Bangor NI	Excessive smoke when idle for period of time?? Evening folks. The 95 850 T-5R has a problem where if sat for a while with the engine running, a LOT of smoke will be produced from the exhaust. It is definitely grey smoke, not steam. The car is drinking oil at an alarming rate also, up to a litre every week or fortnight, sometimes it also feels like the car is down on power. This smoking stops when normal driving is resumed. Anybody know what might be causing this? I suspect the turbo, valve stem seals, or piston rings? Not sure how to diagnose further. As always, any help would be much appreciated. Thanks very much folks __________________ 1996 850 2.5 SE Estate - wrote off 1993 850 2.0 SE Saloon - scrapped 1995 850 T-5R Estate - so far so good...

Nov 9th, 2013, 18:49	#3
Tension Senior Member Last Online: Mar 22nd, 2015 22:53 Join Date: Jul 2009 Location: Bangor NI	Forgot to mention, did the PCV last year, upgraded the vacuum hose etc, so it's not that. PS i've noticed over the years that you seem to be the resident PCV expert round these parts __________________ 1996 850 2.5 SE Estate - wrote off 1993 850 2.0 SE Saloon - scrapped 1995 850 T-5R Estate - so far so good...

Nov 9th, 2013, 18:52	#4
Tension Senior Member Last Online: Mar 22nd, 2015 22:53 Join Date: Jul 2009 Location: Bangor NI	The fact that it only happens when idling for a good few minutes made me wonder is it a temperature related problem, but the guage never moves too much, and the coolant levels have always been fine.. __________________ 1996 850 2.5 SE Estate - wrote off 1993 850 2.0 SE Saloon - scrapped 1995 850 T-5R Estate - so far so good...

Nov 9th, 2013, 21:29	#10
Tension Senior Member Last Online: Mar 22nd, 2015 22:53 Join Date: Jul 2009 Location: Bangor NI	I am 1000% sure it's not the PCV system. So how does a layman go about replacing the turbo seals? Is it an 'engine out' job?? __________________ 1996 850 2.5 SE Estate - wrote off 1993 850 2.0 SE Saloon - scrapped 1995 850 T-5R Estate - so far so good...

Nov 9th, 2013, 18:40	#2
mikealder VOC Member Last Online: Nov 6th, 2016 10:18 Join Date: May 2009 Location: Blackpool UK	Pop the oil dipstick with it running, is it puffing smoke out? if so clear the PCV out but pay especial attention to clearing out the lower port in the front of the engine where the PCV tank connects. This is probably blocked so the PCV isn't doing its job and just burning the oil through the exhaust. Best way to check the lower port is clear is to attach a length of 5/8 rubber hose to the port and try to blow through it, if you can't then it is blocked and needs further work to clear it out - Mike

Nov 9th, 2013, 18:53	#5
mikealder VOC Member Last Online: Nov 6th, 2016 10:18 Join Date: May 2009 Location: Blackpool UK	Did you blow through the lower PCV port though? - Mike

Nov 9th, 2013, 19:54	#7
scvolvo Premier Member Last Online: Jun 4th, 2023 18:24 Join Date: Mar 2013 Location: hertford	Could well be turbo seals? What the movement like on the shaft?

Nov 9th, 2013, 21:13	#9
brickman Premier Member Last Online: May 31st, 2024 15:50 Join Date: Jul 2013 Location: Glasgow	+1 on turbo seals. last two petrol turbo car's I've had smoked (oil) at idle and on overrun when warm below 2000rpm. Both were worn turbo oil seals, one turbo I rebuilt with a cheap (£17) ebay chinese rebuild kit and that sorted that, the other the compressor wheel was seriously worn and missing parts so had to source a recon turbo. But 1st port of call should be breather/PCV system

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