1985 911 turbo ppi

[radelizi]

What key factors play a role when looking to buy a 1985 Porsche 911 turbo. What is a fair market price for a car that is grey market, been repainted, needs engine reseal. I would like to make fair offer, I grade the car 7/10. Also what are key things the pre purchase inspection should cover? Any advice helpful!

[Rawknees'Turbo]

Key things to have a PPI check for, regarding the engine/running gear;

1) Compression leakage test (aka - leakdown test) performed - note percent leakage of each cylinder and from where the leakage is occurring on any cylinders showing over about 10%. This will give you a good idea of the health of the top end (heads, rings, etc.).

2) Remove all rocker covers and inspect for broken head studs or loose nuts (not THOSE nutz!!!) - all Turbos have Dilivar studs on both the intake and exhaust sides and they are garbage which are prone to breaking and also causing inconsistent clamping forces. When the rocker covers are off, all the cam lobes should be checked for pitting (low zinc oils used, and/or condensation buildup from short trips operation), and see if any of the rocker shafts are starting to walk out of their bores.

3) Check for oil in the intercooler and the turbocharger's compressor outlet pipe - there is always some oil present there (a fairly thick film), but if it is pooled, then the turbocharger's bearings are likely about gone.

4) Check the condition of the injector blocks and the tightness of their nuts - those bakelight plastic things are prone to cracking and loosening and an air leak there will cause the dinosaur tech CIS/K-Jetronic injection system to really act up, particularly during boost.

5) Listen closely for chain noise from the timing chain boxes - excessive noise can mean that the tensioners are beginning to fail, or are fully extended due to chain and chain wheel wear.

6) Drain oil and wipe a finger in the drain hole for the oil tank (kinky, I know!!!) - see if there are coke particles in there created by an owner running oil with a low flashpoint. Porsche stupidly returned the turbocharger oil supply directly to the oil tank, where it then travels unfiltered throughout the engine, so if oil cokes in the turbocharger's super heated bearing cartridge, the particles can cause issues (plugged cam spray bars, for one).