I have a ranger with 241000 miles on it and am the third owner, to my knowledge anyway. I drive 112 miles a day back and forth to work five to seven days a week. I do maintenance as required and have tried to keep it in good health but I have had a real problem trying to diagnose a overheating problem that started three day's ago.

I have so far changed the stat and conducted a thorough cooling flush. I did find a small amount of white scale while flushing but nothing to indicate any kind of deposit blockage. All the hoses are in good shape so I don't see them collapsing. I'm not losing water and I don't see or hear my water pump starting to fail. The coolant is of correct mixture. The fan is still turning so I am assuming that the fan clutch is ok. I don't have any indication of a blow head gasket problem.

This might be an additional problem or it might be realated but it has started a slightly lurch when accelerating. Just had my camshaft timing sensor replaced because it wouldn't maintain time.

Any ideas or thoughts besides the local phone number to the scrap yard would be great. Shes been a pretty faithful ride til now... Dave

 

A few questions that might help folks figure it out -

Which engine?

By "overheating", do you mean it's actually boiling over, and puking coolant - or just indicating overheat on the temp gauge?

And how long (from a "cold" engine) does it take to begin to overheat?

My first WAG (Wild A$$ Guess) at this point (if it's indeed boiling over) would be the waterpump - like impeller corroded/separated from shaft. I'd think the radiator would be slow to "warm to the touch", if this were the case - maybe even boil over before the radiator became hot.

Or the radiator's passages are at least partially plugged... did you get a chance to peek at those, during the flush?

If not actually boiling over, I'd maybe change out the temp sensor, and see what happens.

BTW - welcome to FTE, Dave. Somebody around here will probably be able to offer an idea or two!

 

Thanks Moat,

The truck has a 2.3L. So far it doesn't start getting hot until about 25 to 35 miles and indicates only on the gage that it is overheating... I wasn't able to take a gander at the passages. Well, I'm of to try to locate a sensor.

 

Old F*rt rule of thumb: If it overheats in traffic, it's the pump. If on the highway, its the radiator. After years of abuse, not changing the coolant, and even changing the coolant, there can be formed a thing called 'bloom' on the ends of the tubes, which will block or slow the coolant flow. It doesn't slow it enough to cause overheat at idle/slow speed as there it not enough btu/h being given off by the engine. At highway speeds, you get good airflow over the tubes, but not enough flow thru them.
My 2 copper-coateds.
tom

 

Or the fan clutch...been there done that. Or something else that I cannot identify...still trying to figure that one out...

 

The silicone-filled clutch can get weak over time. It will then never engage strongly enough to make the fan do its full job. You can test by watching the fan as you turn off the ignition. The fan blades should stop almost immediately, and never 'run-on' or free-wheel. If you try to turn the blades by hand, ENGINE OFF, (hadda say that, lawyers, u know), it should have some resistance in cool temps, and if really hot, stronger resistance.
Some one (who wants to sell clutches?) said they will last 30-40K miles before getting weak. I don't know.
I think that at idle, there should be a good flow of hot air being pulled out of the radiator shroud, engaged or not. I heard that you should be able to hear the clutch engage if you let the vehicle idle with the A/C on. The sound will suddenly increase as the fan gets 'hooked up'.
tom

 

Another success story....my '93 3.0 was overheating when in traffic..it just kept getting worse. I followed Tomw's advice of watching the fan blade continue to spin - freewheel when I turned the truck off. Bought a fan clutch. Got my 12" Cresent wrench, put it on the fan nut and wacked it with a hammer as I pulled it to the right. It came right off with only one....that's right,...only ONE busted knuckle! Runs cool now; lovin it.....maybe I can get the AC compressor replaced now and actually turn On the AC without fear of overheating.

 

to make sure you dont have a blockage feel the hoses carefully going and coming out of everywhere, rad. heater core, etc. if one hose is hotter than the other you have a blockage. if both hoses are around equal temp. then no blockage, this can also be performed with a tempature gun if you have one available to you otherwise be careful and barely touch them because if you are overheating the hoses could be 300 deg. +