burning oil at idle

Cyman · Post by **Cyman** » 07 Jul 2013, 00:59

I have a 1997 850 turbo that seems to burn oil after I let it idle for a while. While driving it down the road it seems fine but after stopping and letting it idle for maybe 3 minutes or so blue smoke will start pouring out of the exhaust. Shortly after starting to move again the blue smoke stops. (I also get an occasional puff of blue smoke when first mashing on the throttle, too.)

Here are the things I have done so far to help us narrow it down:

Compression test: lowest cylinder was at 167 psi, highest was 175 (rings are good)

Leak-down test: didn't really help much. No cylinders were losing much air.

pcv system: replaced 2000 miles ago. Cleaned the ptc as well.

turbo: has a fresh rebuild. < 50 miles. Burning oil symptoms did not change after rebuild.

My best guess is that I have bad valve stem seals. I searched around the forum and there are a lot of people that have the exact same symptoms as me but none conclusively solved the problem leading me to start my own thread.

any thoughts/opinions would be much appreciated.

thanks

-Cyman

Post by **jblackburn** » 07 Jul 2013, 06:51

You've taken care and eliminated anything else that it could possibly be (PCV or turbo). Compression is fine.

Yep, the smoke at idle means that it's the valve stem seals!

Post by **rspi** » 07 Jul 2013, 08:33

I switched to 10w-40 and all of my smoking went away.

Did you know that the owners manual recommends that you do NOT let the car idle for extended periods of time?

Cyman · Post by **Cyman** » 07 Jul 2013, 09:40

Thank you for the replies

Has anyone had experience replacing the valve stem seals? Does it require me to pull the head off?

Rspi, I was thinking about trying a thicker oil. Right now it has 5-30 synthetic in it, perhaps the thicker oil could help me get by until I have the time to do the seals

-Cyman

Post by **jblackburn** » 07 Jul 2013, 11:55

Try 10W-30 or -40.

Never use a 20W or 50 weight oil.

Whoa (member here) has a whole write-up replacing the stem seals in his 850. Here ya go:
https://sites.google.com/site/incarvalv ... placement/

Post by **rspi** » 07 Jul 2013, 18:54

5w-30 is to light. I have read bad wear stories about it.

Post by **jblackburn** » 07 Jul 2013, 23:57

rspi wrote:5w-30 is to light. I have read bad wear stories about it.

???

Post by **rspi** » 08 Jul 2013, 05:13

One of the threads were on this site where someone wrote that he had not 1 but 2 motors wear out in less than 60,000 miles due to running 5w oil in his car. Can't remember if it was5w-30 or 5w-20 but he said he ran 10w-30 in this other I5 and has over 120,000 on the motor with no issues.

Cyman · Post by **Cyman** » 08 Jul 2013, 09:53

Thanks for the heads up.. I'll swap the oil when I get the chance.

Jblackburn: thanks for the write-up link. It was exactly what I needed

ordered the valve stem seals this morning. Wish me luck!

-Cyman

Post by **jblackburn** » 08 Jul 2013, 10:38

You'll need the luck. Looks like a huge, painful process.

Ill save the oil debate for another thread.