2004 Tahoe is overheating

[rjirby]

I have replaced the water pump, and t-stat, and it is still overheating. I have to add antifreeze and water to it every week. Anyone have any ideas what I need to do or possibly what it might be?

 

[metro273]

I thought I read somewhere that it could be a headgasket?
Do you have any external coolant leaks anywhere?

 

[RenegadeTahoe]

Yeah, you've got a leak somewhere. Check the cap... freeze plugs... check your oil. If it's got a milky consistancy, you have a bad head gasket... if it doesn't, you may still have a bad head gasket..it just hasn't leaked to the oil... An auto shop can add UV dye into it and find the leak for you. (or you can do it... I think major auto parts stores carry it..) then you just need a black light. :thumbsup:

Also check your fan clutch. My S10's fan would run, but not at full capacity. I don't remember having to add antifreeze, though.

 

[Davco]

When does it overheat? While sitting still or driving? Does it cool down when you start moving? How hot does it get?

I'd be a little worried about having to add coolant. It has to be getting out somewhere. I'd take it to a shop and let them test for a blown headgasket.

 

[rjirby]

When does it overheat? While sitting still or driving? Does it cool down when you start moving? How hot does it get?

I'd be a little worried about having to add coolant. It has to be getting out somewhere. I'd take it to a shop and let them test for a blown headgasket.

It wil overheat setting still or driving it. It is actually a Yukon, not a Tahoe. It is my mother in laws vehicle. I believe it has the 5.3 V8. No visible leaks anywhere.

 

[tybardy]

here are some possibilities...


A. your fan clutch is not running the auxilary fan at full capacity or possibly even at all. At which point your truck will overheat because it is not pulling in enough air which will in turn cause the coolant to vaporize (coolant is too hot) and can be getting out through the overflow tank or the radiator cap. This means that fixing the fan should stop the overheating AND the leak. (although if you are still overheating at speeds of 65mph and 75mph this is less likely)

B. you have a pinhole leak somewhere that wont let water out but will in fact let vapor out as the truck gets hotter. As the truck gets hotter, the coolant steam will excape via the pinhole leak which will than cause the coolant to get even hotter which will than cause the coolant to leak faster and faster and you get the point

C. you have a blown head gasket which usually happens because of an innitial overheating problem... i.e. your thermo went out, truck overheated and blew the head gasket.. you replaced the thermo but truck still over heats. this would be a terrible thing and like it was mentioned before, check the oil, if it is cloudy or milky it is for sure the head gasket... although just becuase the oil looks good doesnt mean its not a head gasket. Take it to a mechanic and do a pressure test to find out for sure

if it is none of those things than it is possible that you have some sort of obstruction in the coolant system but this is highly unlikely. Or possibly a vaccuum problem (does this even happen anymore??) other than that i am all out of ideas (of course you could have a cracked block but i seriously doubt that unless she was ran extremely hot for a while)

good luck man, overheating problems are my least favorite!

 

[tybardy]

I thought I read somewhere that it could be a headgasket?
Do you have any external coolant leaks anywhere?

hey metro... arent you a "Nissan Technician in the House!"??

Now i know you dont work on Chevys but an overheating problem is an overheating problem and it is almost always the same problem no matter what kind of car/truck you are driving... figure a nissan tech (or any tech for that matter) would be able to chime in with something a little better than "I thought I read somewhere that it could be a headgasket?"

because an overheating problem could always posibly be a blown headgasket... just hope for this dudes sake that it isnt the head gasket, that is never an easy fix. A good 8-10 hard hours if you do the work yourself and you had better have the right tools (quality torque wrench neccessary)

 

[tybardy]

i forgot to say that if the temp is jumping from hot back down and than back up and than quickly back down you will need yet another t-stat as it is bad

 

[mrlee727]

My Tahoe is overheating too...

Where you ever able to getthis resolved? My 96 Hoe is is doing the same thing! The temp is jumping from hot (240 -260) back down (100-150) and than back up and than quickly back down. I've replaced the T-stat twice, made sue the rad is full and the pump is just over a year old from Autozone. Also I to get the squeal when I first start it, but then it goes away!

 

[DougO]

Hears my two cents my last truck a 2001 xterra extremly well taken care of . At 71000miles the the truck started running hot, After I did everything sugested above I pulled the rad and had it tested. It was cloged solid. Note I flushed and replaced the antifreze at 25k 50k and firestone flushed it at 65k. The rad shop thinks Firestone caused the problem with their machine. just my two cents go to a good radiator shop
dougo

 

[JKmotorsports]

.... The temp is jumping from hot (240 -260) back down (100-150) and than back up and than quickly back down....

That could be an air pocket in the cooling system. Burp and refill the system to make sure there's no trapped air. Another possibility is a faulty gauge or sending unit.

 

[Ojustracing]

Well just to through another bad thing into the mix. But there is a TSB #06-06-01-019b dated June 12 2007(Gradual coolant loss over time no leaks visable) I know about on 04-06 4.8 and 5.3 that the clylinder heads crack/Porosity depending on the casting manufactor.

John

 

[Sepiroth]

The easiest way is to preform a coolant system pressure test on a cold and hot engine. This will almost definitely determine where your, if any, leak is.

If there are no leaks found during the pressure test, then I would say that the problem is now electrical/mechanical.

Get the pressure test done then try back here.

 

[Ojustracing]

I will have to agree with Sepiroth, before doing anything else, go to a shop and have the cooling system pressure tested. As someone in the automotive cooling industry this would be your first step before going any further and getting all worked up about what it could be.

I just found my 06 leaking coolant under the hood at the plastic fitting on the heater core extension for the rear heat. Found a small puddle on the floor wheile lifting it up to change the oil.

John

 

[metro273]

hey metro... arent you a "Nissan Technician in the House!"??

Now i know you dont work on Chevys but an overheating problem is an overheating problem and it is almost always the same problem no matter what kind of car/truck you are driving... figure a nissan tech (or any tech for that matter) would be able to chime in with something a little better than "I thought I read somewhere that it could be a headgasket?"

because an overheating problem could always posibly be a blown headgasket... just hope for this dudes sake that it isnt the head gasket, that is never an easy fix. A good 8-10 hard hours if you do the work yourself and you had better have the right tools (quality torque wrench neccessary)

Dude! I meant it in a sarcastic way...
BTW, I didn't want to say "It's a headgasket." cause then one of you Chevy guys would say "How would you know? You're a Nissan Tech."

 

[dropmech]

My buddy who has a shop told me that I need to get the orange dextron crap out of my engine and replace it. Apparently it contributes to head gasket failures and there's even a class action law suit against GM because some Buick model blows headgaskets due to the dextron.

 

[Fbroach1]

Hey how do you burp or get the air out of the system?