84 944 running warm & shaking

As a follow-up. I took the car to two different professional shops and the second one made a diagnosis. They said that their external thermometers showed that there was not a clog in the coolant system. That they beat on the dash a bit and the gauge became unstuck, or adjusted itself down. (They didn't charge anything for this bit of insight ? ) The gauge still reads around 3/4, or a little less as things cool as winter sets in.

I did question them about the motor mounts and their collapse. They showed me how the original ones were full of fluid and would collapse but once collapsed then they don't generally degrade from there. I went ahead and had them replace both mounts with ones they said were solid rubber.

That helped with the rattle a little. What actually helped a lot was that they adjusted the idle a bit. So now it runs as it always has, which is smooth.

I have a sneaking suspicion that the O2 sensor may have something to do with something, or the DME going bad? Who knows?

Hi, Thanks for the question. Head gasket? I hope not. It burns no oil, so I hope that sign is that the head gasket is OK. Plus, one thing that the second shop did was to sell me a $20.00 radiator cap, so now it doesn't even lose any coolant. As far as I know, the thing is fine. Again, hopefully.

A guy was telling me that, in low profile engines, that the internal oil tubes are very small. So he suggested flushing the engine oil and switching to all synthetic. His rational was that synthetics flow easier and hold less heat. I wasn't sure that was all true and before switching over the oil I asked for a second opinion. The end result is that I did not flush the engine but did switch to a synthetic blend. And again, everything is fine with the motor for now.

There are several reasons that I didn't want to flush the engine. Primarily is the fear that I would throw off whatever homeostatic equilibrium or balance that is going on internally. (That sounds strange but.) If there are deposits in places inside of that motor, and it works fine, then those deposits should stay right where they are. I was worried that if I kept fooling with it that I would break something (oil pump, seals, etc.)
8)
Rad