hey guys i was out wheeling a couple days ago and went through some deep muddy water... on the way down the trail to get out of the woods my truck started overheating.. i stoped once on the trail to let some people on atvs pass and herd the water boiling out.. the temp guage was reading normal, right in the middle.. i couldent do anything but limp out of the trail with the truck overheating.. i got the truck home and looked over everything and decided to go get a new thermostat.. i ended up just taking the old thermostat out and not putting one back in.. <<< is that a bad idea? anyways when i was pressure washing my truck i noticed that the back of my radiator was COMPLETELY covered with about an 8th inch of mud.. this might sound stupid, but is that why my truck overheated in the first place?

Also.. i drove the truck yesterday and it started getting abnormally hot and the temp guage started jumping between extreme hot and exterme cold, (side to side).. does that mean my coolant temp sensor is going bad?, and where is that located? its only like $8.88 at advance auto... could my temp guage in my guage cluster be going bad?

thanks for any help!!

 

Yes, mud can cause your truck to overheat, its pretty common.
Always best to wash it out asap after going in the mud.

But not to alarm you, but I would be watching my hg since you have been "overheating" your engine..

 

it really only over heated once.. the second time i just drove it around for a little while to see if it would overheat again, and it started to..

thanks for the reply!

 

its time for an aftermarket gauge you can pick some up at shucks that look pretty good. yes a radatior filled with mud will cause your truck to overheat

 

i it common for the temp guages to go bad in these trucks?

 

Use a t-stat...it's there for a reason. I'd wash everything off and flush your cooling system.

 

i know more than one person whos gauge is in one of 3 positions cold, warm, or overheating. and for $15 i like having the peace of mind knowing how hot my engine really is. and after "overheating" less than 2 blocks away from my house i wouldnt say i trust the stock gauge. there is proably an easy fix to this but i like knowing for sure how hot it really is

 

It only takes one overheat, espically to boiling, to blow a HG... Mine got part way to red on the gauge and the HG went 1K later...

Reinstall the thermostsat, your truck will never warm up, your mileage will go to crap, and it wont run right.....

 

thanks for all of the replys, but i still have 1 question... where is the temp guage signal sender at?

 

I know there is the ECT on the front of the lower intake manifold . There are 2 side by side, I think the one on the right is it, the other is the cold start injector I beleive.

 

I believe you are thinking of the 22RE. On there, the sending unit (and cold start injector) is up top of the intake and to the driver side of it. Those two side by side are the cold start injector time switch and water temp sensor.

On the 3.0, the sending unit is on the "back" of the manifold next the to temp sensor tucked almost under the plenum. Tricky to get to. Both are to the driver side of the heater hose. The closest being the sending unit. To the left of the heater hose, is the cold start injector time switch.

 

So can you see it in this pic?
http://rides.webshots.com/photo/2406...42310107LmzcSf

 

Which one are you asking about, Dale? The sending unit? If so, yes I can see it. It's just to the left of the heater hose in the pic. Then the temp sensor (for the ECU), then the water temp switch...which I'm not sure what that's for, yet. I've called two dealerships and the parts dept's are not real sure either. Regardless, I need to know myself. So, I will find out eventually. Anyway, to right of the hose (again, in the pic) is the cold start injector timing switch. Then that little part that everyone breaks...

Class dismissed...hehehe....J/K'g!!!

 

Yeah, I got an idea what the water temp switch is for, the AC on the 3.0 autos has a over-temp cut off. If the coolant temp gets too high the AC compressor won't have any power. Mine had to be bypassed with the 3.4 engine swap because the 3.4s don't have that.

 

i putted an aftermarket one in my truck since the old one wasnt really precise
it seems to get not higher than 190 F ,only when i shut the truck down it gets up to about 200 F than it comes back down after a while,i guess cause water is not circulating!!

and my thermostat is new and radiator too!! and i got a new water pump too!!

 

i was at work today and did some good looking throught my haynes manual and found out that the water temp sensor is for the a/c & cooling system.... the coolant temp signal sender (the one with only 1 wire going to it)is the only thing related to the guage in our interior.. the way to test it is to mock up a strong ground and run it to the connector on the coolant temp signal sender, turn the key to "on" if it goes right to hot you need to replace the coolant temp signal sender... its only 10 bucks at advance auto...

i hope mines bad so that i can replace it and then my guage will read correctly!

let me know what your guys findings are!


ttyl

 

For all makes, gauge senders typically have a single wire, ECU senders usually have two or more. Sometimes there will only be an ECU sender.

"Statistically" it's more likely for the sender to go bad than the gauge, but your symptoms point to the gauge... good luck. If you do diagnose a gauge issue, make sure you check all the grounds, they can cause this kind of problem.

 

Thanks Dale...that explains it.

The water temp sensor affects the EFI air/fuel mix...much like a choke on a carb'd motor. If it's not good, then one's mileage, power, and running behavior goes to sh@t.

I knew there was a way to test the temp sender unit! I would have posted earlier about it, but I couldn't remember how it was done. Thanks and good for you on discovering that.

Which grounds are you referring to?

 

haynes repair manual page 12-14,
from what it looks like, theirs a ground on the left behind the instrument panel..



ours is on the left.. advance sold me the other one that has the exact same name but it was 7 bucks... so if any of you guys end up going to get one from advance auto you need the coolant temp signal sender thats like 10 bucks..





got my ground wire ready for tomorrow morning...



peace

 

i made a mistake.. you have to hook up a jump wire from a good ground to the pulg (the one that plugs into the top of the signal sender..) and when you turn your key to "on" if the temp guage goes straight to "hot" you need to replace the signal coolant temp signal sender..


WHOOOOOOOO! i did the test and mine is bad! now all i have to do is replace it and my guage should read correctly again!!!

let me know what you guys find out.