5.0 getting hot

1st make sure no leaves and crap are blocking the radiator if it's an a/c car make sure stuff isn't between the condesor & radiator. you could have a bad fan clutch, when the motor is hot and the engine is off IIRC the fan clutch should not spin freely, it should spin hard . If the fan clutch isn't working then just like an electric fan it isn't going to cool the motor. also make sure the radiator itself is in good condition, make sure the inside isn't crusty and blocking the flow tubes, this will reduce the cooling capacity of the radiator.

going to need more history, what was going on before the over heat issue? what work if any where you doing to the car before the over heat? how long have you had the electric fan? does it cool down any when you go over 35-40mph. If it's hot at low speeds and the w/p is working then most of the time it's the fan or in your case the fan isn't big enough to cool the motor. if it doesn't cool of at higher speeds then most of the time it's the radiator that is bad. you could also have air trapped in the system which will not help.

Are you using an aftermarket gauge?

shaun-d said:

the fan could be to small cause its from a 2.3 mustang

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I don't know the cfms of that fan but it could very well be on the low side. like I stated if it's getting hot at low speeds and everything else checks out then 99% of the time it's the fan. Most of the time the fan of choice is from a Taurus, Contour or the mark 8. you want to be around 2,200 - 2400 cfms, I would think atleast. the taurus fan runs roughly 2600cfms on the low speed side and the mark 8 can run in the 4,000 cfm range. you want something with a shroud, this covers the radiator and aids in the cooling.

What should be the normal temp? Here in Phoenix where the temp get up to 115 in the summer my car runs about 240-250 but it could be the gauge sometimes it will be 270 and then go down to 200 when the coolant starts flowing at high rpm.

885.0conv said:

What should be the normal temp? Here in Phoenix where the temp get up to 115 in the summer my car runs about 240-250 but it could be the gauge sometimes it will be 270 and then go down to 200 when the coolant starts flowing at high rpm.

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could be the gauge, I would check it. with a stock 190 stat normal operating temp is around 210. If the car is running right around 200-210 then I wouldn't worry, even if it creeps past 210 with the a/c on in traffic then goes back down that is okay. If it's running over 220 + all the time, then you need to start troubleshooting that's too hot.

I don't think you have the right fan like I stated. I think you also need to pressure test the system to finish looking at the cooling system itself. if everything checks out, ie hold pressure, no leaks after pressure test, rad is good etc. you need a new fan, you are cooking the fluid.

Depending on the temp that it boils over that can point to a bad radiator cap.

I would swap the cap and then keep an eye on the temp to make sure that it doesn't overheat if you have other issues, i.e. clogged radiator, etc..

My 88 had a problem with boiling over. Put a new radiator cap on it and it solved that problem but then it started getting hot and I ended up having to put a new radiator in. So fixing one problem pointed me in the direction of another.

are you sure you replaced/investigated the thermostat? because at 10:09 you were going to try it and then 10:34 you said that the problem wasn't solved. i'm just saying is all.... the thermostat is on the block, not on the radiator.

I'm with you guys that he needs to do some more digging for sure. I also did some research on here and corral and the 2.3l fan is a very poor choice to try and cool a V8, from what I read it had a hard time with 2.3 and has a low cfm rating. I think he possibly has mulitple problems, like the already mentioned rad cap and possible bad radiator to a cooling fan that cannot keep up.