Cylinder burning oil

[acowden]

I think I know the answer, but I'll ask anyway...

1999 Carrera Cabriolet, 71,000 miles, burning oil in #3 cylinder. Often smokes (blue smoke), sometimes heavily, at startup. #3 cylinder failed compression test - visual inspection after pulling spark plug does not show any scoring. Dealer suggests it is either a bad valve guide, worn oil ring, or cracked cylinder head.

3 questions:

Any thoughts on these possibilities?

Are there other possible causes?

How urgent is it to pull the engine to confirm a diagnosis and repair?

Thanks in advance!

[acowden]

It looks like a bad oil ring - any labor estimates on a ring job for an M96 3.7L?

[JFP in PA]

Originally Posted by acowden

It looks like a bad oil ring - any labor estimates on a ring job for an M96 3.7L?

Upwards of $12K to do a proper rebuild, more if you really want to do it right.

[acowden]

Well, since I can buy 6 x 1999 911's for that price I think I'll hold off...

[JFP in PA]

Originally Posted by acowden

Well, since I can buy 6 x 1999 911's for that price I think I'll hold off...

That should read $12K, not $120K.

[BYprodriver]

Originally Posted by acowden

I think I know the answer, but I'll ask anyway...

1999 Carrera Cabriolet, 71,000 miles, burning oil in #3 cylinder. Often smokes (blue smoke), sometimes heavily, at startup. #3 cylinder failed compression test - visual inspection after pulling spark plug does not show any scoring. Dealer suggests it is either a bad valve guide, worn oil ring, or cracked cylinder head.

3 questions:

Any thoughts on these possibilities? Dealer has suggested least likely causes.

Are there other possible causes? Out of round cylinder, cracked cylinder!

How urgent is it to pull the engine to confirm a diagnosis and repair? How bad was #3 compression?

Thanks in advance!

Dealer dosen't seem to be familar with weak points of this engine. Don't let them disassemble it, R&R only.

[BYprodriver]

Originally Posted by acowden

It looks like a bad oil ring - any labor estimates on a ring job for an M96 3.7L?

1999 comes with 3.4L Most likely cause of oil ring failure is worn cylinder & a ring job will not fix that. If you allow that dealer to disassemble that engine you will regret it.

[acowden]

Yes, sorry, not sure why I typed 3.7L, it is, of course, a 3.4L - and thanks for the advice WRT the dealer!