Heating Problem After Replacing AC Pump

Written by Bill Heath Wednesday, 01 October 2008 10:11

Volume 1 Issue 4 - 6.2/6.5 Issues and Answers

Our ’94 one-ton Chevy diesel seems to have a heating problem that we think began soon after we had the air conditioner pump replaced. The problem is, no one seems to be able to fix this for us. The temperature gauge goes up to 230ºF and back down; up and down it goes. It takes spells of swinging back and forth like this, then seems to be fine at other times. I am not convinced that it ever really gets hot, even when the gauge says it is. The mechanic at our dealership has replaced the thermostat, then the radiator, then the water pump, then the radiator hoses, then the temperature sensor, then the fan clutch and finally another new thermostat; all without solving the problem. After each visit, they tell me it is fixed and send me on my way with a lighter wallet, but the problem returns. Now, after all this expensive work has been done, we have noticed that the oil pressure gauge is reading lower than it used to and that the volt meter reads low. We also see that the speedometer jumps around when I rev the engine in neutral. Then, once in a while, the wipers will make an unplanned swipe across the windshield. Maybe I am being unfair to the mechanics, but none of these problems existed before the work was done. Understandably, I hesitate to take it back to the dealership for fear of the costs. Am I vexed? Can you offer help?