HELP!! my truck gets hot! What do i do?

[recneps]

my ranger seems to get hot when i drive it, but never into the red range on the guage, but the check guage light comes on. i checked the coolant in the radiator and overflow, both levels are fine. belt is fine, fan is turning. could it be the thermostat sticking? or maybe something is wrong with the water pump??

 

[pimtool]

Have you had it in the mud?
Is the radiator full of mud?

 

[snake]

It is almost NEVER the waterpump. They leak sometimes, but rarely responsible for overheating.

Could be the thermostat but that is doubtful too. Most of the time they just stick wide open or closed, but worth checking out, you never know.

You say the fan is turning, is it turning fast enough? A fan clutch can start going out and it will turn but not fast enough. If the problem came on gradually, the radiator may be clogging up and need to be rodded out by a radiator shop. It could also be a head gasket going out. I would check and make sure you don't have more anti-freeze than water (50-50 mix max). Very rare, but could be a lower hose collapsing too.

 

[codeman2468]

Does the heater blow hot? This will tell you the status of the thermostat.

 

[khooper]

if you are able to take it out..do so, then put it in a pot with water, turn up 2 a boil...if ur "stat" opens thats good.....if not..bad.....and it should reclose when you let it cool off...hope this helps
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[86freebie]

ok, i have replied to "these" threads a couple times. my gauge was going into red then to normal then up high. just like yours. get rid of the pos stock gauge and put in a mechanical gauge. all that stoped when i did that, it was 100 degrees yesterday and the real gauge floated between 195 and about 205 under load or city street driving...

you may have a problem, but for the 5 to 10 bucks for stat and gasket just replace them. mud in radiator is a very good point flush it with a hose (not a pressure washer) and if possible get hose to push from engine side out.

 

[Capt Jay]

ok, i have replied to "these" threads a couple times. my gauge was going into red then to normal then up high. just like yours. get rid of the pos stock gauge and put in a mechanical gauge. all that stoped when i did that, it was 100 degrees yesterday and the real gauge floated between 195 and about 205 under load or city street driving...

you may have a problem, but for the 5 to 10 bucks for stat and gasket just replace them. mud in radiator is a very good point flush it with a hose (not a pressure washer) and if possible get hose to push from engine side out.

The reason your stock gauge was showing hot is because your truck IS running hot. 195-205 is to hot. It should be between 160-180 depending on the thrmostat.

As for the original question.

Hose off the radiator and give it a flush. Then check the fan.

 

[MAKG]

The reason your stock gauge was showing hot is because your truck IS running hot. 195-205 is to hot. It should be between 160-180 depending on the thrmostat.

Huh? Stock is a 195 deg thermostat, and 195-205 is very good. Many thermostats will cycle wider than that brand new out of the box.

160 deg is too cold, and the PCM will think you're warming up.

There is no reason whatsoever to use a cooler-than-stock thermostat.

Did you put your temperature gauge in the radiator? That's wrong. It belongs behind the thermostat because that's the regulation you're testing.

 

[RyanD2]

160 deg is too cold, and the PCM will think you're warming up.

I was told earlier that this is too cold, but wasn't given a real reason as to what effect it would have. Good to know this now, perhaps this is why my CEL comes on and throws an O2 sensor bank 2 bad

Driving from Boston to Plymouth, NH I'd say my average temerature reads 180, 160 when heat turned on.

 

[WhiteBroncoII2WD]

I repeat all the above, flushing the radiator, checking the thermostat and also make sure there aren't any air bubbles in the cooling system.

 

[86freebie]

if this is a question to me---"Did you put your temperature gauge in the radiator? That's wrong. It belongs behind the thermostat because that's the regulation you're testing.--- no its in the stock therm housing. radiator will give false reading because its had chance to cool water.

 

[AgPete139]

I just diagnosed a Toyota Supra last week. Same problems, same story as yours. It will climb too if you just rev the engine in "park," and is stays/goies down in temp when it's at idle.

My vote is head gasket. There COULD be water in your crankcase OR small signs of oil in your radiator OR no signs at all. If the radiator flushing solvent & hose flush, the possible air bubbles, no cracked radiator, then it is likely that leak. Sometimes, the is small bits of steam that comes off the engine after it is raced (like revving under the hood while it is in "park"). SNAKE is right about the thermostat either sticking open or closed (hardly does it fluctuate). If it hasn't been replaced in a long time your's is 1999, mine was 1997 and I chabnged it about 3 years ago), might as well replace it anyways (you also completely rule this possibility out). I am usually against buying tons of parts and guess check, but a thermostat (to me) is an item that should be replaced regardless. It's basically a temperature-based spring.

And how much mud could actually be IN the radiator? If it is on the OUTSIDE, it still shouldn't cause it to overheat that much. You don't seem like you wheel hardcore offroad either.

The H2O pump is going to be pumping whenever the engine is running and the belt and tensioner isn't slipping. Even if it leaks, it will still cool your engine a decent amount. If no water leaks under your truck, rule this out as well.

If it still WANTS to overheat when you drive at highway speeds, then it is not the fan or fan clutch. The fan turns off at those speeds and the oncoming air cools the radiator instead. Even if you throttle and re;ease when you drive, the temperature should want to go down again.

Your O2 sensors aren't related to cooling somuch. Fuel and combustion mainly, and this shouldn't be your problem.

Using the heater is does not always tell the status of the thermostat.

I agree with MAKG; normal temperature is around the 200* mark. That's why gauges are usually 140* - 260*.

 

[recneps]

thanks

i flushed it and replaced thermostat. turns out the thermostat was bad. good it was a cheap fix!