Over heating

AZ-Z71 · March 23, 2004

Ok, so I never really found my over heating problem from last year. All I know is that when the temps went below 90 here the over heat problem went away. Now that the temps are over 90 again the same problem is back.

When sitting at idle the temp guage jumps pretty quickly, usually two lines at a time sometimes three lines almost instantly. Looks fine then, BAM it is up. Never gotten into the red but it has been close.

Here are the things that have been done.

1. drained coolant and replaced along with replacing the thermostat with a factory thermostat.

2. Since the body is lifted and the fan now sits about 3" lower than the original location, I used some metal to cover the 3" hole below the radiator (so it wouldn't suck air under) and did the same for the 3" gap at the top so maybe the fan could pull the air from the top.

3. Replaced the water pump which came with a new thermostate (after I just replaced it) and change the fluid again. - This necessary since the pump was leaking - also hoped this was the problem.

4. Had a transmission service done and all looked fine. (Thinking it was a torque convert thing - besides need the service anway)

So the only thing I can come down to would be the stupid fan clutch. Some mornings depending on what the temp outside is I can hear the fan roaring even though the engine is cold. Sometimes I hear it when it is hot out and sometimes I don't hear it at all. The only time it seems to run higher temps would be sitting at idle, like at a drive through and the outside temp is over 90 and the ac is running. I also tried this without the ac running and it seems to do the same thing. So I'm trying to rule out the ac as well. One thing I did notice is that the ac doesn't cool as good when the temp of the truck goes up. Maybe a sensor to shut off the ac when the coolant temp comes up???

Anyway, I'm leaning towards the fan clutch. I don't see any evidence of it leaking, I tried to see if the blades will free spin with the engine cold, (I get conflicting reports on if the should or shouldn't), one parts guy says it is, one says it is not and the other says to take it in and have them look at it.

Part is about $170 so I want to make d**n sure it is it before I start playing the swapping game.

Radiator does not apear to be dirty, fluuid looks real clean. Any suggestions - Fan clutch?

superbee · March 23, 2004

That sounds like a really expensive clutch to me. The fan should turn like the clutch is full of molasses when cold, ie, slow with some resistance. Have you changed your hoses? If you suction side hose is collapsing it will starve the water pump causing a low flow condition in your system (heat up) and also cause premature wear of your pump (pump failure). Hoses shuld be inexpensive, not cheap. I stay away from chain stores and deal with small time parts guys that cater to the local pros. Just some ideas.

Shaners · March 23, 2004

At $170 I would consider dual electric fans. They should move alot of CFM's and you'll gain some extra HP!!!

Are you sure it is an erractic gauge/wire/sending unit?

seadoons · March 23, 2004

It still sounds like maybe your thermostat is sticking...are you sure that the new one that was installed is functioning properly?

AZ-Z71 · March 23, 2004

I haven't changed the hoses yet. They still look good but you could be right. When it starts doing the overheat thing would I be able to see this happening? I thought there was some sort of wire in the hose to prevent it from collapsing. Wouldn't it make it worse if you reved it up higher. Mine seems to be happening at idle. When the guage jumps up and if you were to bring the rpms up to 1500-2000 then it drops the temp guage back off.

I could be maybe a wire/guage/sending unit. I have not checked this either but it doesn't explain why it only happens when the temperture outside goes up. I would figure if it was something electrical it would happen all the time and not only when the temp outside went up. Also, like above if I raise the rpm's the temp comes down.

Thermostat, this is the third thermostat it has done it with. The original, the one I replaced thinking it was the thermostat, and then the one that came with the water pump. So unless I happened accross three bad ones I think I can rule out the thermostat.

Fan resistance when cold is still a little stiff. Could not get it to free spin. Probably turn about a quarter turn when spun. Someone told me that it should free spin when cold????

superbee · March 23, 2004

Wives Tale, will not free spin ever. Try changing hoses and look around inside the radiator holes closely with a flashlight for crud and scale. If you say "Holy Crap!" it's too dirty, get it flushed by a pro. Anything less than that, it should be okay. NAPA used to be able to test temp senders, dunno if they still do, some electrical type on here may be able to help you test it before you buy a new one that you can't return. Lastly, yes usually there are coils inside of the hose to prevent collapse, they rust and dont run the whole length, and the hose can delaminate and the inside be collapsed while still looking round on the outside. Good Luck.

March 23, 2004

I don't recall hearing others with lift kits complain about overheating but it does sound like it could be related. Could be why you also have problems getting cold A/C. The A/C heat exchanger is right there with the radiator. I think the hoses are your safest and cheapest "stab in the dark" but if that doesn't work, before I spent $170 on a new clutch fan I would go with an electric fan. Besides the "claims" of HP and MPG improvements, the new electric fan will align properly with the radiator no matter how high you lift your truck.

JMHO

superbee · March 23, 2004

I agree

Redapple · March 24, 2004

Sounds like the fan clutch to me. At speed you get the additional airflow caused by the movement of the vehicle, even if the fan is slipping. It may run hotter than normal at speed, but at idle is where the temp would really climb. Try a junkyard for the fan clutch. I wouldn't re-design ie put in electrics or change the way things designed. Get to the root of the problem, then formulate a plan of action. You start changing things around, you may never know why it is overheating.

My 2¢

Good Luck

Bill

citydriver · March 24, 2004

You may also want to clean the A/C condensor and radiator on the outside as well, especially if the truck spends time in or around dusty areas.the dust collects inside the fins and affects the cooling efficiency of both......You can spray the outside w/a garden hose...you can use a pressure washer BUT you have to BE CAREFULL not to get too close and hit them w/too much pressure or you can damage them.

Schwag · March 24, 2004

I'm assuming AZ indicates Arizona so this problem needs to be addressed!

I bet this wasn't a problem prior to your lift.

This is simple, you are not drawing enough air through your radiator due to the mis-alignment.

Either construct a tighter fan cowling or go with the electric fans.

I have experimented with different fan locations and if you are off just a few inches it is very noticable.

Based on your spin test and the fact that it is loud upon startup, the clutch sounds fine.

Spend your $$ getting the airflow aligned, your engine and AC will be happy.

steve

AZ-Z71 · March 25, 2004

Here are a few things I need to do first.

1. I need to use heavier metal for my fan shroud plates. The stuff I have now is pretty wimpy and looks a little loose. I'll try tighting that up. The first summer after doing the lift is the summer that the over heating thing appeared. (Last summmer) I did however call Performance Accesories last summer and they seem to know that this over heating was an issue with truck in the summer. (Too bad they didn't put that on the box!) The were working on a solution like and improved fan schroud. It seems like a very simple idea and should be that had to have someone make out of plastic - but then again what do I know. PA suggested to put the metal plates in which I did. But it didn't seem to work so I been chasing around other possible solutions. After looking at the metal plates I put in I'm not really all that happy with how wimpy that look. My idea is that air is still being pushed around or sucked around them and they are not doing a proper job.

I'll start here first by making new ones.

2. I'll check the hoses next. When I had the hoses off to change the water pump I did check inside the radiator and into the block at the openings at it really looked clean.

I'll change the hoses next, couldn't hurt anyway and won't cost me a bundle.

3. I also want to make a plate for my air intake. Probably has nothing to do with it but the heater hose sits lower because of the body lift and I can see K&N being able to suck warm air from the heater hose since the sheilding is not totally protection the filter from the hose anymore.

4. If none of the above work then I'll yank the radiator and and have it flow tested to make sure there is nothing blocking it.

5. Still if that does not work, either a) I'll take it into a professional, b) live with it for three to four months out of the year, or c)consider the electric fans if the fan clutch is good.

mxvin · March 25, 2004

Had the same issue with...dare i say my "old" Ford F250. Changed many thermos,fan clutch,water pump,etc. Finally I pulled the temp bulb...it was cruddy. I cleaned it...then I thought ah what the eff just change the darn thing. No issues since. Try the bulb it may be the issue. Good Luck!!

kdm101 · March 26, 2004

Is it possible that there's some tapped air pockets in the cooling system?

Just my nickle.

covvy · March 26, 2004

Souds to me like its the rad. Try check by getting the truck good and hot the spray some water through the middle of the rad. It should steam right away due to the latent heat in the rad fins. If nothing then odds are that the rad is plugged. Are you running dex-cool? Early dex-cool had a bad habbit of turning to sludge and plugging a lot of things up. With it hot check the temp of the lower rad hose. It should be really hot, if not then again the rad is at fault. I'd have a hard time agreeing that the clutch fan is at fault. Try these simple test first. Good luck.