burning oil...valve seals?

[good_old_geo]

Hi my car burns about 3/4 qt of oil every 1000 miles. I just did a compression test and the pressures in all 4 cylinders are perfect 190-200 psi (almost no variation) . I did not do a wet compression test because the Haynes manual says the max compression is 195 and min is 142. My car puffs out white smoke every morning and when pressing on the gas. I think my valve seals are busted. is it possible that my rings are also bad as well? I read somewhere that a normal compression test does not rule out bad rings.

[mobiless2]

Possible good compression rings & bad oil ring.

[cipher93]

Some condensation burning off in the morning is normal, but I take it this doesn't go away. If it smells like oil (and looks bluish). If it's white it could be coolant, where it would be sweet smelling. Has your coolant level changed much? Also consider looking at test kits to test your oil and/or coolant for combustion byproducts.

[good_old_geo]

coolant level has no been changing. I also noted lots of oil and crud in the intake manifold causing the EGR valve to go bad. Is this the symptom of bad valve seals?

[Zembonez]

Valve stem seals are actually a symptom of worn valve guides in many cases. Replacing the seals will work as a temporary fix... but the real issue is probably wear in the guides. If the engine is a high miler, it may have worn rings. Oil getting past the rings can give artificially high compression readings.

[cipher93]

Originally Posted by good_old_geo

coolant level has no been changing. I also noted lots of oil and crud in the intake manifold causing the EGR valve to go bad. Is this the symptom of bad valve seals?

Check your PCV too... pull it out, and shake it. If you hear it rattling around it's good. If not it needs cleaned/replaced.

[speedy25]

Let me give some clarification on valve seals, since I have seen some very silly misinformation in a few posts.

The seals are RUBBER. Their formulation is a bit of a compromise since they need to survive in hot oil. Rubber and hydrocarbons really dont mix at all but its still the best material. Over time, the rubber loses its elasticity. No elasticity= no more seal. I have also removed seals that had broken because they had gotten so hard. When they cant seal properly vacuum in the intake tract sucks the oil down the guides and into the combustion chamber. I would say that at 100k miles the seals are worn. At 150k they arent working anymore. Thats my estimates, but I'm not the guy who works in the oil research lab.

Somehow a sticky appeared up top about oil consumption. I had not seen it before despite its start in 2007. Read it.

Compression tests tell you very little. Leakdown tests let you know the condition of your upper engine. If you think you have ring leakage you will find it in that test.

-SP

[ganda1f]

Adding to the experience with valve stem seals (VSS), I had a similar oil consumption, between 0.5-0.6 liter every 1000kms. I knew that the VSS would be cooked so I decided to change them regardless of anything else that might need attention. I did that at 290.000kms and as far as oil consumption is concerned, it went down only a little. Now I am at around 0.3-0.4 liter every 1000kms. It depends very much on how the car is driven, spirited driving with frequent acceleration, or sustained high speed 130-140kph increases the consumption to 0.5-0.6 liter every 1000kms. Such conditions before I installed new VSS resulted in 0.7-0.9 liter every 1000kms.
When I got her 8 years ago with 100.000kms it only used 0.15 liter every 1000kms.
Car runs on fully synthetic 5w-40 oil.

I like to think that I have taken good care of my engine for the past 8 years and 200.000 kms, but eventually that thing will need more serious attention like a valve job.
I have not yet got around to doing a leakdown test, but as far as visual observations go, I have no blue smoke ever, only a bit of white in the morning when the car is started cold.

Edit:
Forgot to mention, it is the 1.6l 4AFE engine