noffboy69
TYF Newbie
- Joined
- Feb 8, 2012
- Posts
- 14
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I have a 1998 yukon slt 4door 4x4 with 5.7. Yesterday on the way to the store I noticed I had no heat coming from the heater...air was blowing, just not hot. I also noticed that my engine temp was fluctuation from 120-220. Even running down the road the temp would drop from 200 down to 120. I have no coolant leaking from anywhere, coolant is full, no wettness on passenger floor board, no fogging of windshield, so I don't think the heater core is bad, could this be the result of a failing thermostat? About 3-4 weeks ago I had to install a new heater control valve so that shouldn't be the problem either. Going to install new thermostat and back flush heater core this weekend. If this doesn't work, what else should I be looking at/for?