Mystery

[Fernando Costantini Gomes]

Hello there!

I own a 1990, 928 S Porsche. I had the engine rebuilt one year ago. After the service was done, I drove 800 miles with the car. Never had a problem, regarding the engine or electrical functions. Until one day, I was driving the car in the highway and the engine died. I tried to start it, but it seemed the battery was died. I assumed the alternator wasn't working properly. I took the car to a service shop were I did find out the alternator was ok. Yet, I had it serviced. The problem was still persisting. Then, I decided to rebuilt the starter. Instead I got a new one ( rebuild ) from 928 int'l. It didn't solve the problem. To be more specific, the issue is: The engine starts good at first. Sounds great. Oil pressure high. Voltmeter almost 14. After 4 or 5 minutes the engine dies and won't start again, till it cools down. It is just like the battery or the starter was bad, but remember, I have just exchanged the starter and the battery is new. I don't know if I have a mechanical problem, that occurs after the engine warms up, or if I have an electrical problem, related to ignition, module, or something else. Did anyone ever had a problem like this? I will appreciate if somebody can give me a tip on this. Thank you!

[stepson]

Your symptoms mimic the symptoms of Thrust Bearing Failure. Drain the oil and cut open the filter. Look at the residue from the filter on a piece of paper. Chances are that you will large amounts of metal. Release the tension on your flexplate and measure the endplay of the crank-forward and backwards. Post those values here and my bet is those measurements will be out of acceptable limits. If that is the case, you will need to find a good shortblock to install in your car. 928 International has a 1/2 price sale going on right now. Good luck.

[wvicary]

Verify the ground cables from engine to chassis, they would have been removed when the engine was rebuilt.