My '86 305 TPI overheats badly(above 240 after 15 min street or 5 min highway).My girlfriend cooked the engine with no oil above 260, few days ago. I've changed radiator, watepump, thermosthat, radiator cap, hoses. There are no leaks, system full with liquid. I have the overheating since the cooking!
Of course I filled the engine with oil.
I don't know what else could be the problem.
Please help:
THX:
Pyr

 

Sounds to me like you have a brake dragging or something, are any of the rims too hot to touch after driving?
Also you might look into some sort of blockage in the water jackets on the block, have them flushed real good.
Finally if you have electric fans, you will want to have them turned on sooner than stock, wire up a toggle or do like I did, install a thermomaster chip from Hypertech, it turns the fan on at 170.

 

Does the engine sound normal? Are there any loud noises or squeaking from the top end of the motor? so you're saying your girlfriend ran it out of oil a few days ago to the point where the temp wen tup to 260? What happened then? Did you shut it off or did it shut itself off so to speak?

 

The car shut itself off, after then I put oil in that and filled with water. I started the engine, it cooled itself down, but when I hit the road the tempreture went over 250.
After I've changed radiator, waterpump, etc.
I drowe it today and the tempreture stays on 240-250 if I drive it around 60 mph. If I go over 65mph the temp goes over 250.

 

I think the engine might be pooched after doing something like that and now it's overheating from all the friction from the damaged internal parts. I dont really know but I'd definately get a shop to take a peek at it and see what they thing about it. How did she run it out of oil anyway?

 

Are your fans kicking in? How many parking blocks have you hit? Do you still have an air dam below the radiator?

 

Tough one here. Are you sure its running that hot?? The guage could be screwy I would first check the fan/fans to make sure they work, then put a reliable "not stock" guage on it to make sure it's that temprature. Is thier any indication of head gasket failure? Water in the oil, blowing white smoke? Dumb but, are you sure you installed the thermostat correctly? Spring down.


Hows the oil pressure?

 

Fan ok, thermostat ok, no air dam, no white smoke, sensor 3 months old and it worked corretly before the oil stuff.Oil pressure little bit less than usually 'cause the 250 temp.

 

Thats a :nono: Get an air dam and it wil most certainly cure your highway overheating problems. As for the overheating in traffic (0-30mph), well thats a little tougher. Does the waterpump impeller spin the right way? Does the fan get enough voltage (I know that sounds stupid, but it does matter)? Are any of your hoses collapsing?

A few things to start with.

 

Air dam is very important. In my infinite wisdom I was tired of the air dam scraping so I shaved it down about 3/4 of an inch. My running temperature shot up by several degrees. Need to find a new one and deal with the scraping.

 

I installed a new air dam and my highway tempreture stopped by 240. City 220. Is it usually or it suppose to be less?
THX:

 

Well my 1991 formula 350, with dual fans and air dam intact; my cars runs about 218 to 220 on the highway hot or cold outside temps. When in city traffic at a light during the summer my car stays 220 for a bit then heats to to around 230 to 240 and then the fan or fans come on and brings down the temp to around 225 to 230, this only happens when sitting at a light for 2 to 3 minutes in 80 + weather. I never tired to have my a/c on yet (it needs a charge).

I hope this helps.

 

ABSOLUTELY get an air dam on there!! It's AMAZING hose much of a difference it makes. Even with my Griffen 31x19 my car overheats without the air dam on, ESPECIALLY on the highway (kind of the opposite of what it should). Also, flush your cooling system really good.

 

I've disconnected the trottlebody heating and the radiator core, and it gives me better temp, but it's still around 220-225. I'd like to recharged my a/c and use it, but i think that's gonna be the next orevheating problem.
Has anyone installed dual fan? How did u do it?

What do u mean check the timing?
THX:

 

could also be gummed up coolant passages. did you try to flush teh system?

 

I had jiffy lube to flush the system. They did it with 16 quart coolant. Is it enough?
THX:

 

A word to the wise: Dont trust your temperature gauge. If you all are thinking you are overheating, you need to verify your temperature by some other means.

The computer's temp sensor is pretty accurate, but they can go bad too. A scanner will tell you what the computer thinks the temp is.

The best way is to get, or borrow a "laser" type temp sensor. (racers use them for tire temp).

With the engine running and hot, check the temp at:
- The head (where your temp sending sensor is)
- the thermostat housing
- the "hot" side of the radiator
- the "cool" side of the radiator.

You can then get a better idea of what is really going on. Temp gauges can be WAY off.

With all new sensors, my temp gauge will read 220, but the computer will read 192. When I verify with my laser thermometer, I was indeed running 192. That is almost a 30* difference between what the gauge says, and what is really happening.

It is definately worth checking out.

Also, the laser thermo is a good way to see how efficient your radiator is by subtracting the "cool" temp from the "hot" temp. Some people may disagree, but you should be getting at least a 30* temperature drop from hot to cool, or the radiator may not be working well.