stu in wichita
Well-known member
This weekend, I noticed my temp gauge fluctuating from the bottom of the operating range to nearly the top, then back down, back up, etc. This cycle happens irregularly, maybe every couple of miles. MPH or RPM don't seem to matter. I have 11K on the engine and the temp has always been very steady, regardless of ambient temperatures.
My first thought was maybe a sticky thermostat, which might not be reacting to temperature changes. I changed it out, but that didn't fix it. The store didn't have a 180 degree, so I got a 190. It still fluctuates, but in a slightly higher range now.
I'm thinking of changing the water pump, simply because I can't think of anything else that could be the cause. Maybe the impeller is slipping on the shaft? Have I overlooked anything?
Thanks for any advice.
-Stu
My first thought was maybe a sticky thermostat, which might not be reacting to temperature changes. I changed it out, but that didn't fix it. The store didn't have a 180 degree, so I got a 190. It still fluctuates, but in a slightly higher range now.
- - The system and coolant are very clean, no leaks, and a coolant recovery tank keeps the system full.
- When the thermostat opens, there seems to be good flow at the radiator inlet.
- All hoses are good -lower hose has a spring to prevent collapsing.
- There's no water in the oil or oil in the water so I don't suspect the head gasket. I pressure test it to be sure.
- Drive belt is good and properly adjusted.
I'm thinking of changing the water pump, simply because I can't think of anything else that could be the cause. Maybe the impeller is slipping on the shaft? Have I overlooked anything?
Thanks for any advice.
-Stu