My Pickups engine temp gauge suddenly quit. While it could be the gauge itself, I suspect the actual sensor. Trouble is, looking under the hood, I'll be darned if I can even identify the sensor. Where is the darned thing, where do I look?What year? Do you have a 22R or a 22RE (the difference is fuel injection).
Check the fuses first. Is it not registering at all? Make sure there is enough coolant in the system. The timing chains in these engines have a habit of stretching out and wearing a hole through the timing chain cover into the water pump housing, if the chain is not changed at a certain interval. You can hear the chain chipping away at it in the first few minutes after a cold start if it needs to be changed.
Anyway, the sensor is attached to the intake manifold somewhere near where the top hose from the radiator enters the engine. I’m not sure exactly which one it is, but if you can find it, disconnect the wire and connect it to a clean ground on the engine. Without starting the engine, turn the key on. If it the gage starts to work, replace the sending unit. If not, the problem is somewhere between the gage and the sending unit.
Thanks, you are certainly right about the chain wearing a hole. I went through that about50k miles ago, had no idea why oil and coolant were mixing. Finally I held the timing cover up to the light and there it was.
I think my 22R in my 87p/u did that around the same mileage. After replacing the cover and chain assembly, and flushing the engine, I got about another 30-40 kmi out of it before the compression loss became a problem. I hope you fixed it in time!