Help with oil consumption and leak down test results

[mnmasotto]

I have a 1987 3.2 carrera with 75K original miles. The car has been extremely well cared for and never had any engine work. The car has been driven appropriately(no short trips) it whole life. The car has always had Valvoline 20-50W, changed every 3000 miles, until 50K when the preferred oil was swiched to Mobile 1 15-50W.

Recently the car has been using about one quart of oil every 750-800 miles. The car never, every smokes, even on start up!!!!!!!!! The car has no oil leaks. My mechanic (very well respected local air cooled Porsche specialist) said the plugs always look great!!! The car runs absolutely fantastic. The car has never been abused, raced or tracked. A recent leak down test was between 2-4% on all cylinders. A second opinion said that he was not sure what the culprit was? valve seals, ring?? He recommended a valve job and new rings (assuming the P & C's measure within tolerances)

Question number 1) Do I need to do anything? I do not mind spending the money on a new engine if it is really needed, but is it needed or is this normal for a 3.2 with 75K?

Question number 2) What could happed if I just drive it until is gets worse?

Question number 3) If I refer to the factory Porsche manual this is within normal limits??? However, others with recently rebuilt engines use much less oil. Who do I trust?? A local mechanic has looked at the data and says just drive it!!!

[Henry Schmidt]

Sounds like valve guides.

Originally posted by mnmasotto
.....edit......
Question number 1) Do I need to do anything? I do not mind spending the money on a new engine if it is really needed, but is it needed or is this normal for a 3.2 with 75K?
Seems pretty normal.
Question number 2) What could happed if I just drive it until is gets worse?
nothing horrible.

Question number 3) If I refer to the factory Porsche manual this is within normal limits??? However, others with recently rebuilt engines use much less oil. Who do I trust?? A local mechanic has looked at the data and says just drive it!!!
I agree, DRIVE IT and start saving for at least a top end

BTW: Where is ORANGO County?

[OldTee]

My suggestion is to drive it hard. At the next oil change get rid of the Mobil 1 and go back to the Valvoline oil. New filter too.

[mnmasotto]

The engine was taken apart this weekend. The valve guides were shot! The Pistons and Cylinders were in great shape. The cam lobes had some pitting. I am not sure if I should complete the valve job or buy bigger P&C's (3.4). The cylinders are Allusil. If I re-use my current 3.2 P&C's do I use the same rings or new ones??
Thanks

[Eagledriver]

Sounds like all you need is a valve job. If you keep the old pistons and cylinders you can probably re-use the rings. I've had good luck with that on two engines where the rings weren't worn out. You need to measure the old rings and ring lands or have your shop do it. The bigger pistons and cylinders are nice but do you want to spend that much when your old set is good?

-Andy