My ranger keeps overheating!!!

UnderdogGN · 01:44 PM

Hey guys i know its not a mustang but i figured since its a ford you guys may be able to help me out.

Anyway i have a very weird overheating problem with my 2001 Ranger 3.0 liter.
It only happens about one time per one tank of gas, so 95% of the time it runs fine. Whats happens is, it gets to operating temp and stays there for a while, then out of nowhere my heat blows cold. The temp guage will then drop a bit and seconds later it skyrockets up to the point where it overheats. By the time i try and pull over to shut it off, the temp drops back down to normal.

I have replaced the thermostat and radiator cap thinking it might be the problem but no luck. I have also bled the system of air and it has fresh coolant in it. All of the hoses appear to be fine also. Something weird i have noticed also is that the overflow tank does not have a vent, so the whole cooling system is not vented.

I need your guys help to figure this out!!! It has made me late to class a few times and is getting very irratating!!

Thanks!!!

HISSIN50 · 12-08-07, 01:34 AM

What temps do you read? If you are using a stock gauge, you need a mechanical gauge (even if only temporarily installed) to see what's really going on. Huge temp fluctuations in almost no time (especially if going way up and then way down) are likely a gauge issue.

Do you ever hear coolant boiling or note the overflow fuller than normal?

Is the overflow bottle cap vented? Some tanks dont have a hole at the top but the cap itself has louvers/vents.

Anyhoo, I'd get a 15 dollar mech gauge on there so you can really see what it's doing.

Good luck.

RUNINAGT · 12-08-07, 05:48 AM

The gauge being bad would not make the heat stop working??
Maybe a possible blockage in the heater core? Or heater Coil like some customers call it

Does the engine light come on, if so have it scanned to see if there are any codes stored, pertaining to coolant temp issues.

UnderdogGN · 12-08-07, 05:01 PM

It is not a guage problem because when it reads hot it actually will puke coolant out of the overflow. I do have a vented cap also. I can hear the coolant bubbling up in the overflow, after i shut the truck off from normal driving. And the check guage light will pop on when it gets hot, and then go off when it cools back down so i couldnt do a code scan without the check guage light on right?
Ive heard that it could be an air pocket in the system, but ive bled the system already and it still happens.

Anyways, thanks you guys for the help!

Roland69 · 12-09-07, 05:39 PM

air in your system I would think.

Roland69 · 12-09-07, 05:44 PM

park somewhere so the front is high so your rad cap is higher then the rest of the system. Maby put the front on ramps. Run the truck till it gets hot with the rad cap off. and make sure the heat is on high (I always have it on the floor setting) the coolant level should drop once the stat opens so be standing by with coolant to pour in when that hapens. I use a rad funnel. Look into getting one of those if you work on cars now and then they are the best thing EVER

If you want to speed this up you can stick a long screwdriver or stick inbetween the gas peddal and the seat and have the RPM's around 1800

**85ragtop** · 12-09-07, 06:19 PM

Moved to other auto tech.

woaixiaoxiao1 · 12-26-07, 10:09 PM

It is not a guage problem because when it reads hot it actually will puke coolant out of the overflow. I do have a vented cap also. I can hear the coolant bubbling up in the overflow, after i shut the truck off from normal driving. And the check guage light will pop on when it gets hot, and then go off when it cools back down so i couldnt do a code scan without the check guage light on right?
Ive heard that it could be an air pocket in the system, but ive bled the system already and it still happens.