Compression test

hammertime · Post by **hammertime** » 28 Mar 2010, 12:27

I recently obtained a '98 V70 w/102K miles that has an undiagnosed exhaust smoke problem. I decidered to resolve the issues I knew about first and eventually find the source of the smoke. Having already performed a PCV system replacement on my '96 850, I confidently jumped into the job on the 70. I noticed that the turbocharger had quite a bit of oil showing on the outside, and also showing on the inside of the pipes leading to the intake manifold. My initial thoughts are that this is my smoke source, and wondering if it's a result of the plugged PCV or if a new turbo is needed? I guess I won't know until I've driven it for a while and then check to see if the turbo is still hemoraging oil. While in the middle of the job I figured I would replace the spark plugs being as it is new to me and I don't know how old they are. To my dismay the plugs on cylinders 4 and 5 were oil soaked and I could see the top of the piston on #4 was black and rough textured. Bad rings? (Couldn't see #5, too low) So now I'm thinking that my next step is to do a compression test on the cylinders. Now I finaly get to this question, is this something I can do myself? What is the procedure and what tools will I need? Any thoughts on the turbo?
Thanks

Post by **charlyW** » 28 Mar 2010, 13:36

hammertime wrote:I recently obtained a '98 V70 w/102K miles that has an undiagnosed exhaust smoke problem. I decidered to resolve the issues I knew about first and eventually find the source of the smoke. Having already performed a PCV system replacement on my '96 850, I confidently jumped into the job on the 70. I noticed that the turbocharger had quite a bit of oil showing on the outside, and also showing on the inside of the pipes leading to the intake manifold. My initial thoughts are that this is my smoke source, and wondering if it's a result of the plugged PCV or if a new turbo is needed? I guess I won't know until I've driven it for a while and then check to see if the turbo is still hemoraging oil. While in the middle of the job I figured I would replace the spark plugs being as it is new to me and I don't know how old they are. To my dismay the plugs on cylinders 4 and 5 were oil soaked and I could see the top of the piston on #4 was black and rough textured. Bad rings? (Couldn't see #5, too low) So now I'm thinking that my next step is to do a compression test on the cylinders. Now I finaly get to this question, is this something I can do myself? What is the procedure and what tools will I need? Any thoughts on the turbo?
Thanks

Running a compression test is easy. You need a screw in Compression tester, you can get cheaper press on ones but they are almost useless. Remove all 5 plugs screw in the compression tester then spin the engine over on full throttle after removing the fuel pump fuse and lead from Coi, after half a dozen spins you should have a good compression reading make sure its within the specifications or within at least 10%, for an 850 the compression should be 13-15 Bar for N/A & 11-13 Bar for T5. Sorry no figures for a V70.

hammertime · Post by **hammertime** » 28 Mar 2010, 21:44

Thanks CharlyW, I went right out and borrowed a guage from Autozone, ran the test, all cylinders between 180-190 PSI. I figure #s 4&5 are more oil fouled due to their closer proximity to the entry end of the manifold. I now have a new skill under my belt, thank you.
Now to concentrate on the turbo delema. Any thoughts?

Post by **Ozark Lee** » 28 Mar 2010, 22:14

Describe your leak in more detail. If you have oil on the outside of the turbo it is likely the oil line O ring. I have not dealt with mine yet but I understand that it is a BI-itch to get the collar loosened. IPD sells a special too to deal with it.

If you have a lot - and I mean a lot - of oil on the inside of the turbo line to the intercooler it might be a leaky seal on the turbo itself.

Either of those conditions will cause smoke - it will just show up in different places.

...Lee

trtvolvo · Post by **trtvolvo** » 06 Apr 2010, 15:47

hammertime - have you made any more progress? I have the same issue with my '96 850; rebuilding turbo to (hopefully) address.

hammertime · Post by **hammertime** » 06 Apr 2010, 20:45

About a week ago I finished the PCV job then changed the oil. There was no evidence of water in the oil or oil in the coolant. The original smoke was very wet but had no antifreeze smell. Since then the smoke slowly disapated considerably.Although the weather is warmer and dryer which would make it less visable. I am now taking a wait and see approach with carefull monitoring of oil and coolant levels. After 250 miles there has been no change. In another week or so I will pull the pipes off the turbo to take a peek inside.