slight overheating issue intermittenly

[Andy96XLT]

Hey everyone,
Today as I was driving home from a friends house my ex started to overheat a little. The check gauge light did not go on or anything, but the needle went up to half way between the little temp icon and the H. It usually stays right below the little icon. I turned my heat on full blast and the temp went down after a few minutes. This is the second time in a month this has happened, both times the temp did go back down and never reached the H. Is this something I should worry about? I thought maybe it was just because of the cold weather the t-stat might be sticking but I just replaced the t-stat and temp sensor a year and a half ago. Any ideas? Should i replace the t-stat again or just chalk it up to random cold weather woes? Thanks!

its a 96 4.0 OHV.

 

[CHEESYPOOFS]

have u checked your coolant levels? when was the last time u had it replaced and/or flushed?

 

[Andy96XLT]

I filled the coolant up the last time this happened because it was a little low, I did not check the coolant levels tonight though as its an ice field outside at the moment. I changed the fluid maybe a year ago.

 

[Andy96XLT]

edit-just checked, fluid level is good

 

[CHEESYPOOFS]

do u have an electric or a belt run fan?

 

[Andy96XLT]

belt run, although both times this has happened I have had my plow on... I wonder if maybe it is just blocking some air going into the radiator? I dunno

 

[CHEESYPOOFS]

i suppose thats possible lol ive never had any experience with plows so i dont know lol

 

[Andy96XLT]

yea me neither ha. I know the outside temperature sensor goes out of wack when the plow is on. But if its not the plow any other ideas of what it could be? It seems that if it was the plow it would continuously overheat because it stays in the same spot. Also I have driven with the plow without having this happen... Hm

 

[AMMO_HOOAH]

have you checked to see if your fan clutch is still in good working condition?

 

[Andy96XLT]

I have not, how do I check that? Would that make sense having this issue only rarely?

 

[96eb96]

what brand of stat did you use? Did it have a vent hole?

 

[Andy96XLT]

its the autozone brand which is duralast. It did have a vent hole with a new gasket.

 

[96eb96]

its the autozone brand which is duralast. It did have a vent hole with a new gasket.

Alot of factors could cause temp to suddenly spike. Maybe a combination of the plow, outside temperature and the thermostat not opening fast enough...who knows...
Not saying that is the issue, but if you do replace the stat try a motorcraft. They were revised and perfected for the OHV engine. They do run a tiny bit on the cool side, but that is fine with me. Heat is great.

I read a few bad vibes about duralast t-stats on the web, here is one I recall...I also wanted to save a few bucks but bought the OEM one after research.

http://forums.nicoclub.com/zerothread?id=350268 (toward the bottom of the thread, someone tested the duralast and claimed it took a while to open after the water boiled).

 

[Cobraguy]

Also keep in mind your fan clutch may not operate correctly with the plow on. A thermostatically controlled fan clutch needs air going through the radiator to work correctly. So if you are blocking some, you might get the double whammy of low air through the radiator causing warmer temps plus no fan clutch engaging.

 

[96eb96]

spin the fan at rest and tell us if it spins with resistance or easily. I believe at rest it should not spin much. Others will surely chime in.

 

[my98nnj]

both times this has happened I have had my plow on... I wonder if maybe it is just blocking some air going into the radiator?

Ding ding ding!! We have the correct answer.

The plow definately blocks air flow through the radiator, hance why you've had the increase in temps when you've had the plow on.

Keep your heat on, open the windows if it gets too hot and you should be ok.
Keep your eye on the temp gauge too. You def. don't want it to overheat.

 

[CHEESYPOOFS]

yea im gonna have to go with cobra guy on this one

 

[Earl43P]

Not trying to argue about the plow, but I'll tell you what I found.

I bought a 99 4.0 SOHC Auto Xplr, and fixed a LOT of things on it. It overheated slightly (I caught it early, close to home) when I was test-driving the new transfer case. Figured, yep, flush it and replace the T-stat. No biggee.

Guess what I found? Pieces of another thermostat adrift inside the housing. A spring and a round brass plate (spring support). Most of you know there are different designs for thermostats. The one that was installed was intact and had the "adrift" pieces still installed. So, the loose parts came from a different installation and had been in there for "a while". The new stat was a better design.

FWIW, it is SO much easier to replace a thermostat while you have the upper intake removed (SOHC). I wouldn't even ATTEMPT to do this job without removing the intake.