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I got a 360 & T18 in a 74 F250 an it gets hot after a few minutes. I have replaced the water pump, fan belt, alt. & checked all the hoses an it looks fine. Another thing we did was change the thermostat from a 165? to a 195 would that cause it? An we are going to change the intake out an switch it over to a 4 barrel. An it sat in the building for bout 4-6 months without being start when we were working on trans an other things could that have caused it? The only other thing we can think of it might be is:
1. thermostat not opening all the way
2. intake gasket is bad
3. the block is stopped up some were
4. It might have a air pocket in it causing the water not to circulate right
I think you have most of the basics down. But does it stay cool going down the road or does it run hot at all times?
Did this start as soon as the thermostat was changed? If so that would be my first check. And what makes you think its running hot? Just the needle registering higher on the factory gauge? If so and it happened right with the t-stat change I'd say it might be normal.
Also when the truck was sitting was the cooling system sealed? I've seen mice build nests in open cooling systems quite a few times which results in running hot.
We are still working on it here in the driveway. It is not legal yet. An it worked fine till we put it in the building to do some work an did not start it for like 4 months then when we pulled it out it started overheating. An the gauges don't work need to rewire the whole truck an the cooling system was sealed no mice in it. An it gets hot it seams like it is not getting any water or very little think it might be intake gasket or thermostat. What is the difference in the 195 an 65 thermostat could this be part of the problem or something else. I am going to change intakes & replace the gasket an see if that might help an take the thermostat out an run it an see what happens. Also was told worse case it might be a blockage in the block causing it. Could it be something else wrong with it?
No the engine has not been rebuilt yet. I am planning to do that hopefully over the winter. An when it runs hot it starts steaming & trying to quit. None of the gauges work on it.
Try poping the cap off the rad when it is cold, then let it warm up, see if there is coolant coming into the rad when it gets hot, also if you have a thermometer, see what the actual tem is, and see if there is any cool spots on the rad, that is sign of blockage. Having the cap off during warm up will also help with air bubbles in the system.
I'm gonna say defective thermostat, a quick way to test it is take it and put it in a pot of boiling water and have a thermometer and see what tem it opens up at, if it opens.
Yea but what do you run the rest of the year? An could the 195 thermostat cause these problems if it is not opening or closing right? Could it be a bad thermostat?
I actually dont change it out as the season change. I have only changed it maybe 3 times in the last 10 yrs. I have ran 160 and 195 year round and I never noticed a difference. But that was in Texas, this year im in Arizona so the winters are not going to be to bad.
Did you try the bucket of water trick to see if it is opening?
I run a 195 t-stat, the engine runs a steady 200 no matter what.
You should always run the engine hot, too cold and sludge and condensation can form.
190-215 is good, 220 is getting up there and anything over 230 is "change your underpants" for a street engine. NASCAR routinely runs over 250 during a race.