I'm in a bit of a stress here b/c my mechanic says one thing and I tend to disagree so i figured I'd ask ya'll 87-90 Jeep Cherokee owners what your experience is.
My cooling system is a bit different because it has an aluminum expansion tank that feeds into a plastic overflow reservoir. The expansion tank is always completely full and when the coolant needs somewhere to go when the engine heats up or cools down, it flows from the plastic reservoir to and from the expansion tank.
Temp gauge in the console keeps creeping up to the red zone. Mechanic claims the system is properly burped. Mechanic also says that it's a faulty gauge and that if the engine was overheating, the plastic reservoir would be flowing over. The coolant is flowing to and from the plastic reservoir like it should be but the damn temp gauge keeps saying its in or near the red- especially when driving up hills.
One last thing- I and the mechanic have taken laser temperature readings at both the thermostat housing and the expansion tank but the reading says 210 at the hottest.
My questions for ya'll is:
1) If the system weren't properly burped, would the coolant still be flowing to and from the plastic reservoir to the aluminum expansion tank?
2) Is it really possible that the temperature gauge has some gremlins in it?
3) Is there anything else I may be overlooking here?