[ponchonutty]

Since I hit the 100k mark a few miles ago I felt now was a good time to replace the coolant that was in there especially since I had over heated the motor last winter when the belt popped off because of snow/ice getting in the way of things. Luckily I was close to home and no lasting problems from that issue :blob:

I was first a little upset trying to get a new thermostat. Again, I am one of those that goes overboard on maintenance. I figured since I was in there, might as well replace that. I pooped a little when first trying to get a replacement. Lucky for me I deal a lot with a local dealer and they fixed me up with a decent price on this....

The thermostat is pressed into the water neck housing. GM has been doing very well making GM-only parts yet again!!!!

This project wasn't too bad really. I first unhooked the hoses. The big one from the radiator was the standard slip-clamp style. The other two for the rear heat was a little different. You have to depress the yellow tabs and slide them off. There are specific tools for this but I managed with a small screwdriver. Once I had them off I removed the 3 10mm bolts and the one 15mm bolt and removed the assembly. I had to remove the inner yellow clips off of the old assembly and snap them back on the ends of the 2 hoses. Be carefull not to crack these. I assume using the right tool for removing these hoses will keep that from happening.

I then proceeded with the flush using tap water until I had clear water. I sprayed through the radiator cap and also through one of the small back heater hoses. I then carefully blew that out with my compressor. I put some distilled water in the system then blew that out.

The new housing comes complete with new gasket and 3 new bolts. It was pretty simple to do and also to get at. You can see the new piece installed here

I installed the new housing and hoses then added my 50/50 mix of coolant while having the front end way up in the air. Once it was at the top of the filler neck I started the car and let it warm up topping off the coolant as needed. I would squeeze any of the hoses I could grab trying to bleed the air out of the system. This took as long as anything thing else I had been doing before!!! Of course since I LOVE Amsoil I used their stuff

All and all took me about an hour to do. :cheers:

 

[ls973800]

Very nice! Did you purge or empty and rinse the coolant overflow/reservoir plastic tank? I know with the older GM models those tanks got pretty cruddy. I used to remove them and scrub them out with a bottle brush to remove the film that was always found in them.

 

[6Sixathome]

Nice job :thumb:. I forget, did you have any engine or trans work done?

 

[rbarrios]

pretty cool.

Did you consider to change out the hoses or youll wait for more miles?

On my Trailblazer- at 133,xxx I changed coolant and replaced the upper/lower hoses.

They actually looked really good once I removed them... but for peace of mind...

 

[medicrxdoc]

Thanks for the pics...gonna make it easier for the rest of us that do it ourselves. I plan on this spring for mine.

I am also glad to see that I am not the only one with that oil seep

 

[ponchonutty]

Very nice! Did you purge or empty and rinse the coolant overflow/reservoir plastic tank? I know with the older GM models those tanks got pretty cruddy. I used to remove them and scrub them out with a bottle brush to remove the film that was always found in them.

Yes, I just pulled the hose off and filled it a bunch with tap water then blew that out with my compressor until it was clean. Luckily this wasn't actually too bad inside which means I don't have any gasket failures leaking junk into the coolant!

 

[ponchonutty]

Nice job :thumb:. I forget, did you have any engine or trans work done?

No except for a leaking tranny seal last summer. Not sure if they kept any of the coolant when they dropped the tranny or not.

 

[ponchonutty]

Thanks for the pics...gonna make it easier for the rest of us that do it ourselves. I plan on this spring for mine.

I am also glad to see that I am not the only one with that oil seep

Yes, I've seen others with it worse than mine. I didn't start to notice this until after a few months later when it over heated. It didn't get super hot but enough to the point that it wasn't too good :'( It wasn't for an extended period and it was 10 degrees out when this happened.

 

[XRDreamliner]

Once it was at the top of the filler neck I started the car and let it warm up topping off the coolant as needed. I would squeeze any of the hoses I could grab trying to bleed the air out of the system. This took as long as anything thing else I had been doing before!!! Of course since I LOVE Amsoil I used their stuff

After starting the car, letting the engine run @ 2000 rpm or so is really helpful in chasing out the air bubbles. In past (non-Lambda) vehicles, I'd fill the radiator until it stopped bubbling down, topped it off and tightened the cap. Then I start the car and run at 2000 rpm until the thermostat opens (the upper rad hose will be hot, indicating the thermostat opened). Shut off the engine, loosen the radiator cap slightly, until I hear the air started hissing out, which is helped by the pressure from running the pump at an off-idle rpm.

I'd re-tighten the radiator cap, and then fill the recovery tank to the fill line. Repeat the procedure a couple of times.

 

[ponchonutty]

After starting the car, letting the engine run @ 2000 rpm or so is really helpful in chasing out the air bubbles. In past (non-Lambda) vehicles, I'd fill the radiator until it stopped bubbling down, topped it off and tightened the cap. Then I start the car and run at 2000 rpm until the thermostat opens (the upper rad hose will be hot, indicating the thermostat opened). Shut off the engine, loosen the radiator cap slightly, until I hear the air started hissing out, which is helped by the pressure from running the pump at an off-idle rpm.

I'd re-tighten the radiator cap, and then fill the recovery tank to the fill line. Repeat the procedure a couple of times.

Yes your procedure is how I did my Silverado and my '70 Firebird but it's near impossible to do that on these cars. Trust me, you don't want to take that radiator cap off too many times. After running it a few hundred miles I just take a peek at the overflow and top off with some premix I have in the jug. Talking to GM techs and they even stated it's a nightmare to bleed the air out of these and after doing this, I must agree.

 

[rbarrios]

yours vs a DI 3.6.
We have that FOAM thing in the way. Below the foam and plastic shield- is the secondary HIGH PRESSURE FUEL PUMP- that is run by an extra lobe on one of the camshafts.

 

[ponchonutty]

Still shouldn't be hard to do, just a little more difficult than my ride. ;D