running hot right after starting engine

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mopars

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The engine is a 360 with a big alumin. rad and the engine as soon as you start it is already hot and reading hot in the dash. Is the thermostat no good?
 
mopars said:
The engine is a 360 with a big alumin. rad and the engine as soon as you start it is already hot and reading hot in the dash. Is the thermostat no good?
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What you're saying is after you crank it for the first time it does not take long for it to get really hot?

If that is the case it could be the thermo sticking or you have a restriction somewhere. Collapsed hose maybe?
 
First thing I would do is pull the thermostat put the hose back on and run it a couple minutes w/o the thermostat in and see what if you still get a high reading on the gauge. You can also hold the thermostat with some pliers and put a propane torch to it and see if it opens up.
 
the same thing happened on my 360 It had a new aluminum radiator, i did not have a fan shroud , i converted back to stock radiator with fan shroud , problem resolved it ran at 185-190 never overheated again.
 
Check your rad cap rating, make sure it's right for the system. For every pound of pressure over the boiling point of 212º, the coolant will be raised 3º. A 15psi cap will raise the coolant temp. 45º.

Check for air in the system which can cause hot spots. Bubbles in the coolant might mean a busted head gasket. Any white smoke in the exhaust? Check only when it's not real hot, otherwise you'll be wearing boiling coolant.

If the thermostat was stuck open, it wouldn't be able to warm up properly. There's a warm-up period when coolant goes through the bypass hose in the water pump to circulate coolant in the block. The thermostat only begins to open once things get to operating temp.

If the thermostat was stuck closed, it would overheat, but not right away. Feel the hoses (don't burn yerself) to see if coolant is flowing through it. If the upper hose is cold when the engine is at or near operating temp., the thermostat is stuck closed.
 
you say as soon as you start it? do you mean within seconds or it takes a few minutes? if it is within seconds it is probably the sender or gauge like stated earlier but if it takes a few minutes then you have a cooling system issue.
 
The engine right now, Has a four core alum. rad, thats made the exact same as a slant six rad. Builder made it wrong and won't take it back long story, Anyways, The car was driven home after getting alignment, about a 45 minute drive, On the highway it was around 180 degrees, with 180 themo. in it, When I hit the city part it hit 220 for a bit then got out the city and it started to fall again to 190. This trip was done with a four blade fan.
So I put on a new 6 blade clutch fan and also but on a shourd to keep it cool. Started the car up today and when about 6 minute drive if that and it hit 280 and maxed the gauge so pulled over and it boilded over. So I added water and checked to see if the themo was working, it was, and checked to see heating lines had water they did, The fan was working too.

So what do you think the problem is?
 
rmchrgr said:
Check your rad cap rating, make sure it's right for the system. For every pound of pressure over the boiling point of 212º, the coolant will be raised 3º. A 15psi cap will raise the coolant temp. 45º.

Each pound of pressure raises the boiling point of the coolant mixture by 3 degrees. It does not actually raise the temperature of the coolant.
Click to expand...
 
just turn the key to on enigine off, and see what the gauge does.....possible gauge ,t-stat, head gasket, restricted hose...bad rad, bad coolant LOL
 
mopars said:
The engine right now, Has a four core alum. rad, thats made the exact same as a slant six rad. Builder made it wrong and won't take it back long story, Anyways, The car was driven home after getting alignment, about a 45 minute drive, On the highway it was around 180 degrees, with 180 themo. in it, When I hit the city part it hit 220 for a bit then got out the city and it started to fall again to 190. This trip was done with a four blade fan.
So I put on a new 6 blade clutch fan and also but on a shourd to keep it cool. Started the car up today and when about 6 minute drive if that and it hit 280 and maxed the gauge so pulled over and it boilded over. So I added water and checked to see if the themo was working, it was, and checked to see heating lines had water they did, The fan was working too.

So what do you think the problem is?
Click to expand...
How did you check the thermostat after you pulled over? I would change the stat to a 160. How much anti freeze are you running? Water alone will boil. Just some questions that's all.
 
Ok, so the stat is working , you have a shroud and a clutch fan that works too. a few things i would check is the distance between the rad. and fan, if the motor is running lean, timing, and also feel for hot and cold spots on the radiator in case it is blocked up. even new radiators have been known to be defective. also give us a rundown of the motor setup and if you have a few pics so we can see what you have that might help too. Johnny.
 
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