The Stovebolt Site Forums The Shop Area Engine Shop Over Cooliing 46 235

Hello Gents,

I have a cooling issue with my 46 235 1.5T. The truck doesn't get anywhere near 180 degrees resting between 140-160 and I'd like to to achieve full temperature. I've replaced the thermostat twice which is a 180 degree. I've changed the temp gauge.
The truck has an original radiator which I've had fixed and cleaned out. What other issues could cause it to run cooler rather than hotter? Could the heat riser be stuck wide open and would this account? Thanks

Try covering part of the radiator with a piece of cardboard to restrict the airflow through the core. If the temperature rises then, it might be necessary to use a 195 degree thermostat. Is the radiator an original equipment item, or has a newer, more efficient one been installed? In general, the thermostat controls the minimum temperature the engine runs, and the cooling capacity of the radiator sets the upper limit. A "too big" radiator can cool things down to the point that the thermostat can't raise the temperature sufficiently. Have you tried checking the thermostat to see where it actually opens by putting it into a pan of hot water on a stovetop?
Jerry

I've checked both thermostats and both work well. The radiator is original and the big 3 core. I'm changing the exhaust manifold as the gasket is blown in two spots and the heat riser shaft is broken off where the spring connects.

History on the truck? How long you had it? Outside temp when "overcooling" is happening? Cruising or idling? Fan being used? Water pump pully size?

I've had the truck for 11 years, 46 1.5 to 235. Stock Radiator and fan for big truck. New water pump in 2012, will not warm at any temp, even at 90 degrees outside. stock pulley and belt. make no difference cruising or idling.
This only started several years ago, before it ran perfect heated to exactly 180

How are you measuring the temperature? Try using a laser temp gauge pointed at the top of the thermostat housing, the top radiator tank, and various heights of the radiator core. I'm going to guess you've got a gauge that has gotten inaccurate for some reason. Also, try removing the temp sensing bulb and submerging it in a pan of boiling water. It should read 200+ degrees if the gauge is accurate.
Jerry

Forgot to mention I've tried two gauges

Did you boil test either one?

Yes I did, they are Military temp gauges used in Willys jeeps, CCKW's everything. They are a basic temp gauge, no frills. These are American made, not Chinese

How does a laser temp gauge read? Most people would be deliriously happy with a radiator that cools as well as yours does. Is there some overriding reason for insisting on a specific coolant temperature? If so, just block off part of the airflow until the gauge reads where you like.
Jerry

Thanks for the input, my real reason for wishing to find out is because it didn't always cool like this, as said earlier, it just started this two years ago and nothing has changed except rebuilding the Rochester.

Not running excessively rich, is it?

I don't think so, I'm not seeing any black smoke

Pull the spark plugs. They will let you know.