My friends 94 caprice has a 4.3 and its cooling too much .he replaced the radiator ,heater core , water pump (gear driven) and thermostat 5different times . It warms up the heater hoses get hot when its idling but when you drive off the temp gauge cools off too much and you don’t have any heat . Took it to a garage and they couldn’t figure it out. The garage said they called gm and they couldn’t figure it out either. Any ideas?
is the thermostat stuck open?
Does the Caprice have a thermostatically controlled mechanical cooling fan? If so, the fan could be running all the time which would allow too much air flowing through the radiator and thus give too much cooling.
If the car has an electric radiator fan, I suppose it could be running all the time as well when it isn’t needed.
“My friends 94 caprice has a 4.3 and its cooling too much .”
" . . . the temp gauge cools off too much and you don’t have any heat .
How do you know it’s cooling too much ? It’s difficult enough decifering first hand information, but we’re getting information relayed from a friend.
What’s the story with the coolant ? Does it ever overflow ? Is it ever low or need to have coolant added ? This information is essential. The car could have an internal coolant leak.
It’s entirely possible for a car that seems like it’s cooling too much (no heat in the cabin) to be heating enough or even overheating, especially an older car. It sounds to me like there is a coolant flow problem, but has anybody checked to see if the cooling system holds pressure over time ?
Your friend threw parts at it and didn’t fix it and a “mechanic” can’t find a problem. This shouldn’t be rocket science and I’d start with a pressure (leak down test) check of the cooling system. If the “mechanic” hasn’t done this then take the car to a different mechanic.
Are you certain that the T-stat isn’t installed upside down? You would not be the first to make that mistake.
How’s the rest of the engine? Is the compression good, the ignition strong, etc.? Have you done anything else analytical?
The reason I ask is because if the engine is barely sputtering along with low compression on the few cylinders still operating it won’t be generating the heat it would if the compression were good. Normally I’d expect the T-stat to keep it from runnng too cool anyway, but my enquiring mind wants to know.