Truck Getting Hot

[flareside_thunder]

The other day...Tony knows cause I called him..My truck got a little warm....it went past the L on NORMAL for these crappy idiot gauges. NO I haven't hooked a mechanical gauge up to her yet to see actual temps, although you can definitely hear it boiling and know it's hot. NO I haven't hit parts of the cooling system with a thermogun to get a relative handle on things and where the issue may be.I may however, do that tomorrow. I do know I just bought a new T stat and it didn't seem like it was opening so I pulled it out and put nothing back in. Along with that I've replaced my fan clutch with a newer used one but it was actin funny and had me worried so the old girl got a Flexalite fan with a 2 1/2 inch spacer. In addition to that she also got "Water Wetter" and one gallon of straight antifreeze with the remainder onf the system filled with water AFTER I thoroughly fluched the radiator and block out with fresh water...Letting the truck cool down for a few hours of course. I finally got to drive it at night so I'm still a little finicky of the situation as of yet...not having driven her in the heat of the day. I also learned that pulling the hood off with bring underhood temps down by two whole letters...once again on the idiot gauge. I am relatively sure it's not the pump also since I had the cap pulled and revving her up she shot water up and out a good foot and a half. Elvira...why be so cruel to me???? I did like every other frustrated truck owner does and threatened to trade her off...I've already got my eye on one too! Anyways..any other thoughts or comments are greatly appreciated...I need to bounce these symptoms of some other heads for a bit and see if I can't get somewhere. Also, I checked for any seepage from gaskets on the timing cover area and saw nothing...There are also no other fluids mixed with each other. I also threatened to blow her up and drop a 6.0 in her...my buddy said he'd help me fund it and do the swap....heh I found the engine tranny and harness for 2500 bucks on a 120k engine.....

 

[Skandocious]

Well first off... The water temp gauge is not as much of an "idiot light" as the other ones such as the oil pressure gauge (which is literally supplied with an on/off signal from a pressure switch). The temp gauge does it fact get a variable input from a temperature sender so the fluctuation that you're seeing is somewhat accurate, though it doesn't give you any indication of what the actual numbers are since the gauge lacks a number key. So don't disregard what the gauge is telling you. Having done lots of work with my efan I know that the gauge does in fact tell me if and when the engine is running too hot or too cold, which is about all it's good for.

That being said... If you weren't having this problems before changing your t-stat and fan clutch then I think it's pretty obvious where the problem lies. Don't wrack your brain about gremlins and such, the problem is obviously with one of those two things, or both. I'd revert back to a stock fan clutch maybe from a junkyard at first to help diagnose the problem, then possibly buy a new one later if need be. What kind of t-stat are you running? Motorcraft stock part number? If not, same temp calibration as stock? You didn't install it backwards did you? I don't take you for someone who doesn't know which direction to install a t-stat, but we all make mistakes every once in a while.

 

[flareside_thunder]

It's all good man...and to set ya straight everything I've said that has been done was done AFTER the truck got hot.....not before. And yes I did install the T stat the correct way but as of now it's non existent.....FYI it was a 195*......

 

[Skandocious]

Gotcha. So you were installing the t-stat and new fan clutch in effort of fixing the overheating issue? The only other real component here is the radiator. Are the fins clogged with dirt or mud? Run a high pressure nozzle on your garden hose through those fins and see if you get anything. Rick's truck was overheating and he wracked his brain about it before realizing his radiator was caked head to toe with dried mud

If not, have you been using any "stop leak" products in your cooling system? Those can sometimes clog up the pipes!

 

[flareside_thunder]

Yes I swapped that to fix the issue to no avail. Nothing clogging the radiator and no flat fins...no coolant loss from the system either and stop leak is only a bandaid and can make stuff worse so no I have never used any kind of stop leak in anything on mine....

 

[surewhynot]

It's possible that the radiator is getting plugged up inside.

 

[flareside_thunder]

Yea, I was thinkin that earlier.....Hmmmm if only I had a nive 4 core to throw in it...oh yea!!! Some lousy cracker stole it!!!

 

[blackhat620]

Have you checked the timing? If it is incorrect the truck can overheat. Also check for vacuum leaks or a bad O2 sensor that may be causing the truck to run lean.

If you have an automatic transmission, what is the tranny doing, is it getting hot? Hot trans fluid will up the water temp as well.

Also re-install a t-stat, as you need a certain amount of restriction in the cooling system for it to cool properly. Without a t-stat many times the water flows to quickly through the system not allowing the radiator to properly cool the coolant.

Also pressure test the cooling system and cap, if the system is not maintiaining 15-16psi pressure then the coolant will boil at a lower temperature and not cool properly.

 

[1985 Ford F-150]

Are ya sure the water levels up? I was goin up over the pass out here yesterday and it boiled over on me. I go it down most of the way and stopped to let er cool down. I had a gallon and a half of water with me so I dumped that in and got it to moms house. I let it cool down again and it took another gallon of water. It was fine after that and I drove it back home without gettin over 190 degrees. It dont leak any so I think its been boilin off slowly over time.

 

[blackhat620]

Are ya sure the water levels up? I was goin up over the pass out here yesterday and it boiled over on me. I go it down most of the way and stopped to let er cool down. I had a gallon and a half of water with me so I dumped that in and got it to moms house. I let it cool down again and it took another gallon of water. It was fine after that and I drove it back home without gettin over 190 degrees. It dont leak any so I think its been boilin off slowly over time.

"Boiling off" to were? You have a closed cooling system, if you do not have an internal water leak that is burning off in the cylinders or an external water leak (check closely) then the system is not holding pressure at the cap. If the cap is not maintaining 15-16psi pressure then the system will boil at a lower temperature and the water vapor will escape out around the cap resulting in a slow water level decrease.

If you cannot find a visible leak, pressure test the cooling system and the cap. If you do not have the tools to do this then take it to a mechanic that does and pay them to do it.

Also you added about 10 quarts of water to your cooling system, this is about half its total capacity, that is alot.

 

[surewhynot]

Have you checked the timing? If it is incorrect the truck can overheat.

Would the timing being to advanced or too retarded cause this? Just curious.

 

[blackhat620]

Would the timing being to advanced or too retarded cause this? Just curious.

Both actually, but generally too advanced is more commonly seen.

 

[countryboytn]

If you cannot find a visible leak, pressure test the cooling system and the cap. If you do not have the tools to do this then take it to a mechanic that does and pay them to do it.

Wouldn't it be cheaper to just get a cap first, and try that, before spending money on getting it pressure tested?

Just a thought...

 

[flareside_thunder]

Oh yea...got new 13 kb cap......still have yet to drive her...been runnin errands with buddies and ridin with them.

 

[Old_Paint]

Hmm, new cap, new t-stat, fresh coolant/water, good pump flow. The cap end of the radiator is also the end the suction hose to the water pump is on. Top hose is return to rad. So, if it blew coolant out the filler neck when you revved the engine, yep, sounds like the pump is OK.

Are you getting excessive coolant over in the reservoir when it gets hot? I don't like to be a doomsayer, but all the problems you're describing indicate a blown head gasket. If you're sure the radiator's OK and not plugged up that even more so points at a head gasket. Exhaust is VERY hot and if it's leaking into the water jacket, it will superheat the coolant. It doesn't sound like a really bad leak, if it is, though. Enough to get the coolant hot, but not enough to blow it out of the system.

One other thing could be it isn't properly "burped" get a big bubble in the system and it'll run warm. When you flushed the system, you get the heater core too? It's always a good idea when you're flushing one to disconnect the heator hoses, and run water through that backward. That will also help extend the life of the core.

I've got a '92 that I've owned since it had 16 miles on it. I can't recall EVER seeing it run hot. It's only had the coolant flushed twice in the life of the truck. When it smells bad and looks bad, I get it flushed. After running 10 minutes, the gauge is centered, and it stays there. 195 t-stat seems a little warm. I think the OE t-stat is something more like 187. It hasn't been all that hot down here in the southeast lately, either. COULD be, just maybe, a bad sending unit. Or did you say you replaced that? I'll give you the benefit of the doubt of knowing which is the sender (1-wire) and which is the ECT sensor (2-wire) for the EEC.

Does it cool back down when idling? If so, you might want to check the bottom radiator hose, and make sure it's got the steel coil in it to prevent it from collapsing. If the coolant you removed was in bad shape, chances are, that steel spring inside the bottom hose has rusted and broken, and is letting that hose collapse after the T-stat opens. If that happens, it'll restrict the flow into the water pump.

Scratching my head on this one, because high temp, but not boiling over is a little odd on these trucks. You can put a 4-core in it if you like, but the stock radiator is PLENTY big. It's WIDE, and the tubes are large, so it cools rather quickly. Boiling over more often than not is a blown HG. They'll actually run a little warmer with something less than 50/50 water/coolant mix. You might wanna check your numbers on your mix.

 

[countryboytn]

VERY Informative post! Reps for that!

 

[flareside_thunder]

Coolant overflow in the reservoir yes...Cleaned and thoroughly flushed the radiator out...Wrapped the lower hose with a thick heavy copper wire to prevent collapse.T stat is non existent.......See how she runs tomorrow...if nothin helped then I've already got the head gasket kti sittin in the truck......Also got a line on a 351 too so we'll see numbers for that thing tomorrow! Thanks for the info.

 

[70torino429]

Coolant overflow in the reservoir yes...Cleaned and thoroughly flushed the radiator out...Wrapped the lower hose with a thick heavy copper wire to prevent collapse.T stat is non existent.......See how she runs tomorrow...if nothin helped then I've already got the head gasket kti sittin in the truck......Also got a line on a 351 too so we'll see numbers for that thing tomorrow! Thanks for the info.

Wait...theres no thermostat in it? That itself can make it overheat...

 

[flareside_thunder]

Update......flushed radiator out reeeeal good last night...wasn't too bad but there was some scale inside and just a littl bit of dirt around the edges of the fins..... Now only runs hot when at idle and cools pretty good at speed. Bought a 180 T stat (Courtesy of Tony's advice) gonna pop it in there here in a bit and hope like hell my issues are gone.Also, gonna change the oil as well.

 

[blackhat620]

Update......flushed radiator out reeeeal good last night...wasn't too bad but there was some scale inside and just a littl bit of dirt around the edges of the fins..... Now only runs hot when at idle and cools pretty good at speed. Bought a 180 T stat (Courtesy of Tony's advice) gonna pop it in there here in a bit and hope like hell my issues are gone.Also, gonna change the oil as well.

Couple of things, 1) i know you live in sunny Florida, but a 180F T-stat may not bring your truck up to proper operating temperature for the computer to function properly. 195F is the standard temp t-stat for all computer controlled vehicles as the need this higher baseline temp to operate properly. If the engine does not reach the proper temperature the computer will not let it go out of cold engine strategy and enter closed loop. 2) Since it is running hot "only at idle" now then it may be a product of no t-stat installed or the new flex fan may not be drawing enough air through the radiator. The flex fan should be installed so that half the width of the fan blades are inside the shroud. It could also be a bad water pump. If after you install a t-stat it is still getting hot at idle check for proper fan air flow and then if that is not it check the water pump impeller.