QuestionPart #2 . This is what I thought as I know inactivity can cause this problem.I am cocnerned about the head warpage as the engine was very hit. It probably took 4 hours to cool. If I had to guess, the enginer had to be in about the 400 degree range (estimated from my barbeque thermometer when cooking)
I started it back up and did not see anything and it purred like a Porsche) No nocks or rattles. Any further thoughts or diagnostics?)
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Followup To
Question -
I took my porsche out today (1985 944) it was alittle chilly so I turned on the heat a bit and it really blasted out. I turned it off and was driving about 20 minutes and saw a read ligth come on on my temperture gauge. I drove and then pulled over.
I saw some smoke and my engine was super hot. I turned off the car and let it sit. I open the radiator cap a bit and coolant came out but it was cold. Further checking showed that cold air came out of the heater now even thought the car was super hot.
I noticed the electic fan did not come on. So I was thinking that since my car sat all winter, perhaps it is the thermostat?
After letting the car cool down (nearly taking 4 hours) I started it again and it sounded fine with no visible sounds noices or leaks. However I am hoping it is just a thermostat malcfunction but any other thoughts concerns ideas?
Answer -
Lee,
Congratulations, that's the best description I've ever read for a thermostat malfunction. A very accurate depiction of the result of a thermostat not opening at the prescribed temperature. Good job.
Now, if I ever hear you say you opened the radiator cap (even if it's just a bit) not long after the car was "super hot" I will take away your mechanic priviledges forever. I don't care how easy you released the cap, that scares me. It should scare you too.
Anyway, the thermostat may have frozen in it's closed position from lack of use...I'd change it right away. The electric fan didn't turn on because it's signaled from the radiator temperature, not the engine block temperature. I'd assume for the moment it's OK.
One last thing to check for. Keep an eye out for coolant leaks from the cylinder head. You probably shut down in time, but if you'd gone on the next event would have been a warped cylinder head, coolant leakage from the head gasket area, loss of compression, and an engine shutdown whether you liked it or not.
Overall, you've diagnosed it very well...I think the thermostat is the only trouble spot. A new one will get you and your little beauty back out on the road again.
Dave
AnswerHi Lee, thanks for the nice feedback.
Unless you see the obvious signs of external coolant leakage you may be OK. Two more things you could do:
1. Check the oil at it's next change for water evident in it. These two don't mix and wouldn't be found together in a healthy engine.
2. Do a compression test, looking for a particularly out-of-synch cylinder, i.e. three cylinders at 130 psi, one at 100. It would be great to compare these readings to a previous test, buy not absolutely necessary.
If the engine passes these two tests, I'd stop looking. If the head is actually warped and exposes itself to you at a later date, driving it now by assuming everthing's OK won't further warp the head.
Now clear your mind of negative thoughts...those Porsche engineers are pretty clever...that head may just be OK.
Dave
