Porsche Repair: 911 87 carrera targa, air conditioner compressor, unseen problems

Question
the owner was a collector so he didn't use it, when I bought the car,2 months, I change the oil, fuel pump oil filter. I did not chage the air filter, fuel filter,sparking plugs and the ignition coil.Do you recomend to chage those items? -------------------------
Followup To
Question -
thanks for the response but I have to tell you that the engine fail when the tempeture gets to the normal position I have no problem whith overheating my car only have 12000 miles when I bought it the owner told me that he change the normal chip for a perfonmace chip do you thin to try the car with the normal again?-------------------------
Followup To
Question -
sorry about my english,the problem is that when the engine gets hot it began to fail and stop then I've to wait for restart it, and when I try to restart inmediatly white smoke came out, then when restarted again no smoke during drive,in cold engine have no problem, when I use air conditioning the problem is more frequent.

Thanks

Answer -
Hi Juan,

Your English is fine, it's your car I'm worried about.  

I'll be honest and say I've never worked on a Porsche with air conditioning, so I' a bit unsure how that all fits in.  But I can surely say the extra stress on the engine to turn the air conditioner compressor could easily add up to an overheated engine.  

I suspect there may even be a sensor measuring the oil temperature or the head temperatures that will shut down the engine's computer when it gets too hot.  

The real issue is the problem of running too hot in the first place.  How many miles are on the engine and would you consider it well maintained?

Dave
Answer -
Hi Juan...

So the car has barely over 12,000 miles?  While the low mileage is a plus in many ways, it also actually causes a concern:  the engine has been run 12,000/18 years= 666.67 miles per year.  This is amazingly low.

If my math is correct the car basically sat more that it was run.  This can cause unseen problems in the engine, especially if the oil wasn't changed at least twice a year.

Is this correct?

Dave

Answer
Juan,

Well, that explains the low mileage.  I'd definitely change the fuel filter and as for the other three, I'd take a look at them to see their condition.  Then decide whether to replace them.  

Here's a possibility for the bigger issue.  Let's say the car was not only driven little but when it was driven it was babied.  Or...many times the car was started and perhaps only idled to get the oil circulated or charge the battery.  In either case, the result would be extra carbon build-up in the combustion chambers.  This would be one cause of the white smoke you saw.

When the combustion chambers get overly laden with carbon, the compression ratio actually increases.  This causes the engine to work harder to get the same performance.  It doesn't necessarily explain why the car died though.  That one still has me stumped.

Dave