Jeep Forum but need Chevy help

[xjintx]

Dan, is deployed and here at home his 2004 Chevy Tahoe 5.3 L 4x4 gas not hybrid is overheating. I've picked it up and am attempting to fix.

I'm no mechanic by any means but handy... I know little about this engine.

1. started by removing Thermostat and testing. In boiling water it opened fine.
2. I noticed that when I removed the thermostat very little water or coolant came out.
3. I replaced thermostat with new O-ring type gasket bought new just in case. I'm old school and used to gaskets a thermostat.
4. NOTE: this model has the thermostat on the bottom hose. This is a sealed system and has no radiator cap. So I filled the reservoir to the fill line and ran the engine.
5. Top radiator hose started as cool and no flow... engine heated to 210-220 and hose filled with water hard to tell but seemed like moving.
6. temp to 240 and I shut off... top hose very full/hard and the overflow bottle had gone up about an inch past the full mark.
7. engine cooled and the reservoir dropped low again... I filled again.
8. repeated same process 2 more times for a total of 1 and 2/3 gallons of 50/50 antifreeze.

OK, so I have not much if any knowledge about these sealed systems I am leaning towards a bad water-pump but also seems like symptoms of head gasket. I don't want to waste time and money on water-pump if other issues because that requires a GOOD mechanic not me.

I am open to ideas or your experiences. His wife needs her car back so she can quit driving his MJ

Thanks,
Roger

 

[iluv83vettes]

I was looking on EXPO in the Full size forum yesterday and there was a guy saying that the coolant that Chevy uses is real bad about corrosion and stopping up the system. Guy had to replace the whole system basically. I was a little bit older one though. Don't know how different they are.

 

[xjintx]

yea this one is / was pretty rusty from what little drained maybe a flush is in order? Except I can't even find a drain plug Googled it and where it is shown there is not one on this radiator

 

[blenny]

Does over heat on the freeway as well?
I assume it's an electric fan and not mechanical?
I would flush it and i think some auto part stores will test the coolant for hydrocarbons for free to determine head gasket

 

[Ls1more]

could be a bad water pump, my 2000 sierra with the 5.3 sheared earlier this year. white smoke out the back? also could be the y pipe from the heater core.

 

[sandsgg]

No smoke that I can remember. To be fair it happened right before I left

 

[86XJ4.3L]

If it is using the dexcool type coolent just get that crap flushed out and put in good universal fluid. How many miles are on it? The water pumps are fairly easy on these to do if thats what it ends up being. Might also see of a parts store has mechanic stethoscope and listen for the prop inside the pump to be turning? Does the heater work? Might try taking the thermostat out and running without to feel for pressure to build up in the radiator hose. Just a few things to try.

 

[xjintx]

how did you determine that Y pipe? The thermostat is good I'm 99% positive. BUT the top hose is the drain hose... starts out pliable but after therm opens remains very hard if you try to squeeze like little or no flow.

Note is was pretty nasty water / antifreeze and low. I added Oreilly univesal 50/50 close to 2 gal

 

[Ls1more]

if it had dexcool and you added 50/50 the system is clogged now, try and flush it out again.

i put some water wetter and the green color of it leaked out and was able to find the y pipe leak, with antifreeze it stayed clean and the crack was a hair line crack that was leaking only when moving.

 

[DeftwillP]

I'm in the flush the block camp. And replace water pump as I'll bet the vanes are rusted almost off.

 

[Mechanic209]

With the way the coolant flows in these engines it is hard to get all the air out. You can fill then let it run till warm, remove the cap and top off. I have dealt with this many times at work and home.

 

[sandsgg]

I think a flush at minimum. Just keep receipts roger so I cab pay you back

 

[xjintx]

OK, I'm back from vacation and need to get back on this issue.

I bought a flush kit today and more anti freeze. Now dumb question... it appears no drain petcock or such? The top hose is the apparent drain hose from radiator back to block. Bottom hose goes to thermostat.
How can I flush????

 

[DeftwillP]

Stick a screwdriver through the bottom of the radiator. That'll get it all out.

 

[sandsgg]

Lol I don't want a new one of those

 

[DeftwillP]

Oh it won't damage the screwdriver. Pretty sure you wouldn't need a new one.

 

[sandsgg]

Lol. You gonna have a nice light German brew waiting for me when I get back

 

[sandsgg]

Any update?

 

[Vanimal]

screwdriver trick worked, all the coolant is out.

 

[xjintx]

Dan, I picked up a waterpump yesterday. I will try an replace today. Added a flush-kit and flushed with prestone flush and no fixy
My mechanic that owns a Cadillac GM shop here in Waco says it sounds like head gasket?
Although he suggests I try waterpump as it probably is going to need replacement anyway.
If that is not the fix I will turn into his place for an expert analysis.
I'll keep you posted. I got back Tuesday but have been playing catch-up