oil consumption numbers?

[captainlewis]

85 carrera at what oil consumption per thousand miles indicate that the valve guides are reaching the end of their tour of duty? thanks JL

[Steve@Rennsport]

At 800miles/qt,...it needs new guides and exhaust valves.

[robert walsh]

Scared to open this can of worms all over again, 800 mi per qt is well within porsche spec, I guess you'll have to take it from there.

[Zef]

Originally Posted by captainlewis

85 carrera at what oil consumption per thousand miles indicate that the valve guides are reaching the end of their tour of duty? thanks JL

Any smoke...?

[captainlewis]

no smoke not even at start up, JL

[BE911SC]

If no smoke at start then 1 quart per 600-700 (ish) miles is acceptable? What if there was STP Oil Treatment in the oil to hide smoke? (Can of worms, continued.)

[Joe Bob]

STP sucks....just use dino oil and maybe consider a straight 30 weight in the summer. Avoiud synthetic.

[E Sully]

BE911SC,
How is the car being driven? A lot of high rpm or average? If your getting 600 miles a quart I would definetly check the top end. A leak down test will let you know if it has ring leakage or valve leakage, but not if the valve guides are worn. If it smokes a little when you let off the gas or the exhaust valves are oily that is an indication. If a valve fails because of worn guides it gets expensive fast.

[BE911SC]

Originally Posted by E Sully

How is the car being driven?

Actually, it's an '85 911 with over 120K miles and is for sale. Good-looker. I am planning to look it over the weekend. Yes, PPI is planned. I've read a few threads on oil consumption and valve guides, etc., and I am not too worried yet. Just don't want to have to do a top end before it's necessary.

[shrtshck]

My 87 3.2 with 100k on the clock had a bad drinking problem, I called it quits when she got up to a quart at 300 miles. Since rebuilding the top end and fresh rings she is back down to about 1500 miles between oil add.

800 miles doesn't sound out of line for a high mileage 3.2, some engines seem to run forever while others of the same vintage trash their valve guides at an early age. Seems to come down to luck of the draw.

[BE911SC]

Another thread here mentions the '86 and '87s could troublesome/faulty valve guides and that many had oil-burn issues as early as 50,000 miles. '84-'85s seem to be much less problematic in this department, according to the same thread.