2003 Tahoe coolant system leak or head gasket leak?

[tomloans]

Changed the oil at 150 miles today ( 2nd oil change since cylinder head replacement ). Then ran it 140 miles round trip. Took wife to the ocean for some fish and chips.

Home | Barbara's Fishtrap

www.barbarasfishtrap.com

You want to order the full Fishtrap. Huge assortment of fried scallops, prawns, fish & calamari. Amazing plater of food. Just remember, they only take cash!

Anyways....
Beautiful quite ride. Still smell radiator fluid but don't see a loss of fluid in the pressure tank. Very strange. Wherever it is, it is a very slow leak. Will keep watching until it shows up.

On another great note, wife said she has never heard the engine run so smooth! Yahoo! Mission accomplished!

Thanks again everyone.

Also if you want a highly rated source for some remanufactured heads, these guys are and they are who I purchased from...

Aluminum Head Rebuilders - Portland Oregon - rebuilt cylinder heads, exchange cylinder heads, cylinder head repair, new cylinder heads. Import and domestic cylinder heads.

Specialists in rebuilt cylinder heads, exchange cylinder heads and cams. Complete cylinder head repair, specializing in hard to find cylinder heads, import and domestic.

www.aluminumheads.com

Ask for Chuck or his son Charlie.

I bought my 799's from these guys and they shaved them for me as well so I have a near match of my 706 compression. Plus well packaged shipping in a very sturdy box for a fair price. Perfect condition.

 

[KVacek]

Old thread but FWIW I had this symptom. Turned out to be the heater core. If you've ever done that job you know how desperate I was NOT to do it on this truck. I flushed thoroughly and used Bar's Leaks but the leak continued. Drained that brand new Dex Cool and flushed really thoroughly again - flush and then a whole afternoon flushing with clear water to make sure all the flush was out. Put in a container of Bar's Leaks aluminum sealant, refilled, and it's still fine 2 years later. I did burp it thoroughly and still added coolant several times over the first few days. Once again last year, but it's fine now.

 

[tomloans]

Old thread but FWIW I had this symptom. Turned out to be the heater core. If you've ever done that job you know how desperate I was NOT to do it on this truck. I flushed thoroughly and used Bar's Leaks but the leak continued. Drained that brand new Dex Cool and flushed really thoroughly again - flush and then a whole afternoon flushing with clear water to make sure all the flush was out. Put in a container of Bar's Leaks aluminum sealant, refilled, and it's still fine 2 years later. I did burp it thoroughly and still added coolant several times over the first few days. Once again last year, but it's fine now.

Thanks how did you determine it was the heater core.

 

[tomloans]

As Tony said, you can try cleaning it. Or, replace it. It's only about $25. I'm not sure, but just unplugging it might cause faults in your HVAC system. If you go through the trouble to access it to unplug it, you might as well just replace it.

I replaced mine about six months ago: https://www.tahoeyukonforum.com/threads/growing-up-doesnt-have-to-suck.93510/post-1615656

After looking at the pictures of the sensor, it just looks dirty and needs to be cleaned. Going to try to clean the one above my head and see if that will work. Otherwise factory sensor is $50.00ish. Although I did find this...

ACDelco® 22834330 - Genuine GM Parts™ Cabin Air Temperature Sensor Aspirator

Genuine GM Parts™ Cabin Air Temperature Sensor Aspirator - Part Number 22834330 (022834330) by ACDelco. Quantity Varies By Application. Available in Parts Department.

www.carid.com

 

[KVacek]

Thanks how did you determine it was the heater core.

The leakage eventually became noticeable, and came from the HVAC case drain hose. Pressure testing made it leak there more.

 

[iamdub]

After looking at the pictures of the sensor, it just looks dirty and needs to be cleaned. Going to try to clean the one above my head and see if that will work. Otherwise factory sensor is $50.00ish. Although I did find this...

ACDelco® 22834330 - Genuine GM Parts™ Cabin Air Temperature Sensor Aspirator

Genuine GM Parts™ Cabin Air Temperature Sensor Aspirator - Part Number 22834330 (022834330) by ACDelco. Quantity Varies By Application. Available in Parts Department.

www.carid.com

Maybe. But, for the trouble of getting to it (more like inconvenience of having to deal with it), I opted to replace it. Cleaning it might have worked, but it's a tiny motor with bushings that couldn't control the fan any longer. In my mind, cleaning it might restore the balance, but the slack in the armature from the bushing wear would still be there.

 

[tomloans]

Maybe. But, for the trouble of getting to it (more like inconvenience of having to deal with it), I opted to replace it. Cleaning it might have worked, but it's a tiny motor with bushings that couldn't control the fan any longer. In my mind, cleaning it might restore the balance, but the slack in the armature from the bushing wear would still be there.

Well the front one is quiet as a mouse now. I was able to remove it and take it apart. Qtip and electronic cleaner around the base of where the fan spins worked. I also just simply sprayed heavily the entire part with electronic cleaner as well. Wiped as much off with a q-tip as I could. I think the main spot that needed cleaning is the cylinder which the fan spins on. I sprayed it very lightly with some Seafoam "DeepCreep" afterwards as well. Can't hear it at all now.

Easy to get to and take apart and clean. The one in the back is the tough one to get to. I simply sprayed it with electronic cleaner a couple of times. It is better but really needs to be taken apart and cleaned proper. Another day for that trouble.

 

[tomloans]

Wow the truck continues to run. No more loss of fluid. I think the smell may have been from it having pooled somewhere in the engine well as a ton of fluid spilled during removal of the heads. The smell is almost completely gone. Most important part is that there is no loss of fluid any longer! Thank you all with special thanks to iamdub! Awesome Awesome awesome!

 

[tomloans]

Here is the old one prior to cylinder head replacement..

 

[tomloans]

Here is the new one after an oil change at 15 minutes, 200 miles and then 800 miles later...