Hi everyone. I'm in California with a 1970 Fiat 500L. I have a genuine question for the team as I'm not mechanically savvy with cars. For quite sometime now my car will drive for a mile or 2 and then shut down (stall). Won't start for another 45 minutes or so. This happens so often, too often. I read something in the Classic Fiat Manual that talked about the thermostat. I went to look at the thermostat on my car and it was not in the location which is to the left and a little up from the distributor. Is there supposed to be a thermostat on this car? If so is this most likely my cause? Your thoughts? Thanks!

CW

It's unlikely that the lack of a thermostat would have any involvement in the engine overheating. When it fails or is missing, in theory, the flap where the heated air exits the cowling should be forced wide open by a spring; in non-Mediterranean climates, a more likely result would be overcooling. I would first check if the flap is fitted; you can see it just to the side of the distributor.

You will get lots of suggestions about the causes of overheating and related engine issues, but it would be good to first eliminate a jammed closed exit flap.

Personally I don’t think that your car will overheat to the point of cutting out in just 1-2 miles. Has the car always done this or is this a recent development ? Has the car had any recent work done on the engine, particularly the ignition ?

I had a Lancia that did the same thing. It turned out to be the distributor that was the culprit. When engine became warm and the metal expanded, something internally in the distributor would ground and the car would cut off, and it would not restart until it cooled for a bit. The coil could be a possible problem too. Next time the car dies, do a spark check.

I would say the problem is the Coil
Alan

One of the 'problems' of the 500 is that the hot 'engine cooling' air is directed over 2 things that don't like heat---the condenser and, if fitted, the electronic unit of an 'electronic' ignition. You haven't told us what sort of ignition you have on your car.
If it is the standard 'points' ignition with a condenser, this can be overcome in the UK by fitting a 'competition' condenser (from Swiftune) where the design of the condenser, with long leads, allows the condenser to be mounted alongside the coil, out of the flow of hot air. The bulk of modern condensers are very cheaply made, hence the 500s habit of going through them at a fair rate.
The problem is a tad more difficult to overcome if an 'electronic' ignition, be it an expensive '123' system or the relatively cheap "Hall effect" system is fitted. Somehow the flow of hot air over the distributor has to be reduced. I have built a small dam inside the thermostat housing, in line with the distributor, which has reduced the temperature of the distributor by about 10 degrees in relation to the themostat housing.
If you have 'points' ignition, I would suggest that the first thing to do would be to fit another condenser and see if that cures the problem. If it doesn't, come back to the forum and we will put our collective heads together to try and solve the problem!