exhaust oil smoke when braking
#1
exhaust oil smoke when braking
Hi all, had my car almost 3 years now, it's been a dream with no leaks and no smoke. never had to fill oil between services.
recently there has been smoke from the exhaust when stopping - coming to a junction, etc. i've also noticed a few puffs at idle, both hot and cold. last week, for the first time since buying the car i had to fill oil. there are no obvious drips/leaks from the engine that i can see. i found one old post suggesting this type of behaviour is often due to worn valve guides (https://rennlist.com/forums/964-forum/258884-smoke.html) and may indicate a top-end rebuild, but the car had one around 25k miles ago.
One recent thing that happened that may or not be relevant - the engine carrier recently broke (https://rennlist.com/forums/964-foru...nging-out.html). has been repaired and no damage to oil lines (or anything other than the carrier) was detected at the time.
so. i'm going to take it in for a check soon, but do any of you guys have ideas on what could be happening, and whether it's OK to keep driving (daily driver).
Cheers, Andrew.
recently there has been smoke from the exhaust when stopping - coming to a junction, etc. i've also noticed a few puffs at idle, both hot and cold. last week, for the first time since buying the car i had to fill oil. there are no obvious drips/leaks from the engine that i can see. i found one old post suggesting this type of behaviour is often due to worn valve guides (https://rennlist.com/forums/964-forum/258884-smoke.html) and may indicate a top-end rebuild, but the car had one around 25k miles ago.
One recent thing that happened that may or not be relevant - the engine carrier recently broke (https://rennlist.com/forums/964-foru...nging-out.html). has been repaired and no damage to oil lines (or anything other than the carrier) was detected at the time.
so. i'm going to take it in for a check soon, but do any of you guys have ideas on what could be happening, and whether it's OK to keep driving (daily driver).
Cheers, Andrew.
#2
Do you have the engine tray in place? If yes, perhaps you have a small pool of oil collected there and its sloshing onto the exhaust when you come to a stop. To find the source of an oil leak, I suggest jacking up the car, remove the engine tray, clean everything. Then take the car for a spirited drive. Bring the car home, jack it up and look for shiny or wet spots.
By the way, I keep my engine trays off the cars, safely stored in the basement.
By the way, I keep my engine trays off the cars, safely stored in the basement.
#3
Do you have the engine tray in place? If yes, perhaps you have a small pool of oil collected there and its sloshing onto the exhaust when you come to a stop. To find the source of an oil leak, I suggest jacking up the car, remove the engine tray, clean everything. Then take the car for a spirited drive. Bring the car home, jack it up and look for shiny or wet spots.
By the way, I keep my engine trays off the cars, safely stored in the basement.
By the way, I keep my engine trays off the cars, safely stored in the basement.
#5
the tray is on, but the smoke is coming directly from the exhaust (ie in the exhaust gases), as if there is a leak inside the engine somewhere.
Do you have the engine tray in place? If yes, perhaps you have a small pool of oil collected there and its sloshing onto the exhaust when you come to a stop. To find the source of an oil leak, I suggest jacking up the car, remove the engine tray, clean everything. Then take the car for a spirited drive. Bring the car home, jack it up and look for shiny or wet spots.
By the way, I keep my engine trays off the cars, safely stored in the basement.
By the way, I keep my engine trays off the cars, safely stored in the basement.
#6
If its coming out the exhaust, then I would suspect that you have an over filled oil level or remnants of an overfill. Have you checked the oil level recently? I mean, when the engine is hot, on a level surface and idling for at least a minute, checked by the dip stick.
My suspicion is that you have some overfilled oil is in your intake plenum.
My suspicion is that you have some overfilled oil is in your intake plenum.
#7
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You likely overfilled the oil, which then runs into the intake plenum. This results in smoking as the oil is carried over into the combustion chamber.
You may actually have a small pool of oil in the intake that shifts under braking and gets sucked into the engine.
The first step is to accurately check your oil level. If it indicates an overfill, you will need to disassemble the intake and clean up the residue.
EDIT: Oops. Sorry Rob, didn't see your response (great minds think the same....)
You may actually have a small pool of oil in the intake that shifts under braking and gets sucked into the engine.
The first step is to accurately check your oil level. If it indicates an overfill, you will need to disassemble the intake and clean up the residue.
EDIT: Oops. Sorry Rob, didn't see your response (great minds think the same....)
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#8
Hi Lou & Rob, the smoke was initially appearing with a normal oil level, measured by gauge and dipstick. The oil level slowly lowered over a couple of weeks, to the extent that I had to refill (which I've never had to do on this car before between oil services), smoke still appearing. The level since the refill is normal by gauge and dipstick, and has lowered a little in 2 weeks, though not as fast as before.
I guess there could have been a previous overfill - I'll check the intakes as you suggest - but I'm confused as to why the oil level has been dropping as well.
Cheers, A.
I guess there could have been a previous overfill - I'll check the intakes as you suggest - but I'm confused as to why the oil level has been dropping as well.
Cheers, A.
#9
Here's a DIY on cleaning the intake. Keep us posted on what you find.
https://rennlist.com/forums/964-1989...-cleaning.html
https://rennlist.com/forums/964-1989...-cleaning.html
#11
Hi all, had my car almost 3 years now, it's been a dream with no leaks and no smoke. never had to fill oil between services.
recently there has been smoke from the exhaust when stopping - coming to a junction, etc. i've also noticed a few puffs at idle, both hot and cold. last week, for the first time since buying the car i had to fill oil. there are no obvious drips/leaks from the engine that i can see. i found one old post suggesting this type of behaviour is often due to worn valve guides (https://rennlist.com/forums/964-forum/258884-smoke.html) and may indicate a top-end rebuild, but the car had one around 25k miles ago.
One recent thing that happened that may or not be relevant - the engine carrier recently broke (https://rennlist.com/forums/964-foru...nging-out.html). has been repaired and no damage to oil lines (or anything other than the carrier) was detected at the time.
so. i'm going to take it in for a check soon, but do any of you guys have ideas on what could be happening, and whether it's OK to keep driving (daily driver).
Cheers, Andrew.
recently there has been smoke from the exhaust when stopping - coming to a junction, etc. i've also noticed a few puffs at idle, both hot and cold. last week, for the first time since buying the car i had to fill oil. there are no obvious drips/leaks from the engine that i can see. i found one old post suggesting this type of behaviour is often due to worn valve guides (https://rennlist.com/forums/964-forum/258884-smoke.html) and may indicate a top-end rebuild, but the car had one around 25k miles ago.
One recent thing that happened that may or not be relevant - the engine carrier recently broke (https://rennlist.com/forums/964-foru...nging-out.html). has been repaired and no damage to oil lines (or anything other than the carrier) was detected at the time.
so. i'm going to take it in for a check soon, but do any of you guys have ideas on what could be happening, and whether it's OK to keep driving (daily driver).
Cheers, Andrew.
#13
Classic worn valve guides or broken rings, IMHO. If onset was sudden and oil consumption is significant, I think it points to the rings.valve guides wear slowly, so smoke gradually appears. I think deceleration on stopping changes the crankcase and cylinder pressures and pushes oil past the rings. Hope I'm wrong, but I've been there.
Good luck.
Good luck.