Over Heating problem help.

[PowerSlideGT]

Okay i have a 90 modle ho motor, And for some strange reason it keeps over heating. There thermostat in the insturment panel doesnt work effectivly, I dont know what to do. I have bought a new thermostat for it. And the only other thing i could think it might be would be the Radiator. Unless there is a relay or somthing to the insturment panel or any thing. Please help. Also the lid of the radiator is messed up. It wont seal properly. So im not sure if thats it or what.

[racerboy88]

check your rad to see if it's clogged up. Mine was and I replaced the rad. Things were all good after.

[stang_racer20]

Yeah I'd look at the radiator as well.

[tireburner163]

Radaitor cap won't seal..........car will over heat. Your problem is a $5 radaitor cap.


-Josh, aka the tireburner

[95_MUSTANG_95]

Radiator cap is a cheap fix. I had the same problem, but mine was related to the cooling fan. Before I finally replaced the fan I pressure tested the radiator, replaced the thermo and the cap. Pressure test is simple but, you need to get a pressure tester for ~$65.00.

The cooling fan has 2 speeds. Make sure it is turning on when the engine is heating up. Mine kicks on before the temp needle gets to the normal range. When it was broken it would not kick on until it was in the middle of the normal range. Only the high speed setting was working. Eventually the fan just quite working.

Hope it helps.

[PowerSlideGT]

Yea the radiatior not sealing off may be the problem, Except that its the radiator lip not the radiator cap, so i have to get a new readiator i guess. One other thing, when it gets to hot, and you stop at a stop sign or somthing the car well die, and wont start untill its a little cooler, i hope its the radiator and not the water pump or any thing. Im going to change radiators and the insturment panel as well. I have a 140 mph any ways. But is the radiator a 3 core or what, just wondering because i found a 3 core radiator for a mustang but i didnt know if it was stock or not. Thanks

[tireburner163]

No 3-cores aren't stock, but they rock. I've got a 3-core in both of my cars and they rock.

Don't replace the gauge cluster, try replacing the temp sensor.




-Josh, aka the tireburner

[PowerSlideGT]

Where exactly is the temp sensor at?

[canukracer]

if your askin about the gauge sender it's LH side near the distributor
grounding the wire should make the gauge go to hot! if not wiring or guage is no good if it moves it's the sender

[Ieatcamaros]

You do have the fan shroud on don't you? What about the shape of your fan blades and fan clutch? To test the fan clutch, take your belt off and turn the fan by hand. If it has little resistance, it may be your clutch. It is probably not any of these, but you need to check them. Is the lip where the rad cap goes bent? If so, that is your problem. There is a good thread a couple of pages back on a overheating problem.

[PowerSlideGT]

Yea the radiator lip is rounded off and or broke off so you can turn it and it gets decently tight, but when pressure is there and or it turns and lets steam and pressure out. Also i filled the radiator full of water and such 2 days ago, and when i looked in it today it was near empty and there was water in the reserve. What advice is there to get. So far i have a clutch fan to look at, a radiator to buy and a temp sensor to check.

[HISSIN50]

ill toss out my two cents worth. i may have missed something, so i apologize (the thread is long).

you have a mechanical fan, right? someone was talkin about an electric fan, which changes the whole dynamic.

if the car overheats or runs really hot on the highway, that suggest the radiator is at fault. overheating in town suggests an ancillary cooling component.

your gauge: the stocker is famous for sucking. get yourself a good aftermarket gauge, even if it is a parts store gauge (Autometer being the best, IMHO). and using a mechanical temp gauge is best. get yourself a good gauge before proceeding - otherwise you are shooting in the dark. if you want to retain the stocker and have questions, lemme know. i have info from a write up i did on another site (i dont want to post links to other sites in here -seems rude).

the stock gauge sucks and does not read well. they are "tuned" to not fluctuate much, as it is 'distracting' to drivers. that is why our oil pressure and temp gauges dont move much. the voltage regulator behind the cluster helps do this, while exacerbating an already useless gauge.

make sure your fan has no cracks on the blades or hub. they are famous for cracking.

fan clutch: stangs come with thermo-clutches. the fan should turn easy with a cold motor, and become harder to turn with a hot motor (as the clutch locks up). DONT TEST IT BY JAMMING YOU HAND INTO A MOVING FAN!. IT HAS BEEN DONE.
with the car off, give it a spin. note how much it freewheels. warm the car up. turn it off. spin again. it should spin much less than before. if not, a new clutch is in order.

also, if you take the clutch off and see silicone leaking on the thermospring on the back, get a new one. many parts stores offer a heavy duty unit with a lifetime warranty. each year, they lose a few hundred RPM (all clutches do).

i agree about 3 cores. they are the only way to go. you might need to massage the lower support, but it is basically a plug and play.

what are you running coolant wise? a 50% 50% mix of DISTILLED water and coolant (some run a little deviation) is something to shoot for. water is what cools the motor - coolant provides lubricity, raises the boiling point and prevents rust. i tend to run 40/60 coolant/water, respectively. i live a 1/4 mile from the sun.

the pressure from the rad cap raises the functional boiling point....so that is important. although, on a properly functioning system, one can run with no pressure and be ok. but stangs are kinda old school - some new cars run 3 times the pressure we do.

and when you get it up to snuff, you can seal the fan shroud to radiator....weatherstrip works real well. you want as much air as possible running across the coil - sealing those up does help.

something not touched upon so far, i dont think: your thermostat. your old one could simply be stuck closed. i would highly recommend a Mr Gasket 180* unit. it is fully balanced, opens fully sooner, and flows a little more than parts store units. 10 bucks at a speed shop. also has a bleed hole, which is nice.

i think that is about it. like i said before, i covered a lot of what was already said, but i was just thinking off the top of my head; there are too many good posts to read through to see if something was mentioned.

good luck to you.