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I had a leak in antifreeze, overheating and overflow was full. I changed fan clutch and Water pump in November. Had a faulty fan clutch so exchanged it. Then leak again in March. Found a crack in radiaotr. Changed it and both hoses and 2 weeks later overheating again. Found fan clutch was out again. I changed it and drove 180 miles. Found antifreeze on ground under truck. Drove 10 miles and again, more antifreeze. Overflow is still full. Checked radiator and was a gallon low. What could it be?? Also have been having code p0014 lately but think thats another story. (Changed vvt solenoid, thinking timing chain with that one) Please - on the verge of shopping for new car due to stress and worry.
 

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2002 Chevrolet TrailBlazer LTZ 4.2L
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Have you pressure tested the cap? Check the tightness of the clamps around the hoses, as well as the condition of the hoses. Overheating could be air trapped in the system. You didn't mention if a bleed procedure was completed.
 

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2005 Chevy TB LT 4.2L
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I had a leak in antifreeze, overheating and overflow was full. I changed fan clutch and Water pump in November. Had a faulty fan clutch so exchanged it. Then leak again in March. Found a crack in radiaotr. Changed it and both hoses and 2 weeks later overheating again. Found fan clutch was out again. I changed it and drove 180 miles. Found antifreeze on ground under truck. Drove 10 miles and again, more antifreeze. Overflow is still full. Checked radiator and was a gallon low. What could it be?? Also have been having code p0014 lately but think thats another story. (Changed vvt solenoid, thinking timing chain with that one) Please - on the verge of shopping for new car due to stress and worry.
As for the P0014 I believe the camshaft position sensor could also trigger that. Being overdue on an oil change or poor oil change maintenance in the past can also cause the issue. I had it myself and the VVT sensor fixed it, but I also ended up replacing the position sensor as well. Did you replace it with an ACDelco?
 

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'05 Chevy TB EXT
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Have you pressure tested the cap? Check the tightness of the clamps around the hoses, as well as the condition of the hoses. Overheating could be air trapped in the system. You didn't mention if a bleed procedure was completed.
Actually - if the 4.2 won't clear the air in the block in a very short time, you've got a different problem.

It's not because it just trapped there --- it's being created there. In just a few minutes, all the air will be out of the block whether the thermostat opens or not.

The Atlas engine cooling system is not anything like most other vehicles.

Edited for SPELLING
 

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Discussion Starter · #5 ·
As for the P0014 I believe the camshaft position sensor could also trigger that. Being overdue on an oil change or poor oil change maintenance in the past can also cause the issue. I had it myself and the VVT sensor fixed it, but I also ended up replacing the position sensor as well. Did you replace it with an ACDelco?
Yes, changed both sensors and oil change every 3500 miles. I also you full synthetic. I'm down to timing chain I'll assume... Only thing I haven't changed is as far as radiator is the heater core.
 

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'05 Chevy TB EXT
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With no codes, no engine problems (or you'd get a code anyway) --- the motor mounts let these engines vibrate badly at idle, in gear especially.
 

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'05 Chevy TB EXT
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I would have like to be a member of the Kerouac "The Beat" Generation with a French beret, black turtleneck and black Chinos & open toed sandals ... but, alas, I was in the Hippy "Tie-dyed", "Grannies", "Paisley Bells" Generation with some Surfer-Hodad Generation thrown in.
 

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2002 Chevrolet TrailBlazer LTZ 4.2L
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I'm the generation right after you then. The generation of bright colors, big hair and a shitload of Aquanet. The hair metal bands looked like women and sounded like the got their nuts caught in a zipper. Slayer, Metallica, Anthrax, Megadeth and the like were in their infancy and there was a glimmer of hope in everyone's eye.
 

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2004 chevy trailblazer_lt
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metalmike187, I'm right in there with you!
 
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I had a leak in antifreeze, overheating and overflow was full. I changed fan clutch and Water pump in November. Had a faulty fan clutch so exchanged it. Then leak again in March. Found a crack in radiaotr. Changed it and both hoses and 2 weeks later overheating again. Found fan clutch was out again. I changed it and drove 180 miles. Found antifreeze on ground under truck. Drove 10 miles and again, more antifreeze. Overflow is still full. Checked radiator and was a gallon low. What could it be?? Also have been having code p0014 lately but think thats another story. (Changed vvt solenoid, thinking timing chain with that one) Please - on the verge of shopping for new car due to stress and worry.
What it ended up being on my 05 trailblazer…after replacing the thermostat, water pump, flushing out the whole system…still had good hoses and clamps…it turned out to be the damned radiator cap! I’ve gone through 2 since I got it 5 years ago…it doesn’t have a pressure release anywhere on the coolant system except for at the cap so if it’s doing any boiling over for no reason…it’s probably that stupid cap..

when u refill the coolant, when it shows it’s topped off, do u run the engine with the cap still off till it’s warm and circulating to get all the air out of the system? Check out the videos on YouTube the channel is Chris fix…the one he does about head gasket leaks and how to diagnose if u have one…I chased the same issues in another vehicle for over a year and finally found the issue was a bad head gasket by the exhaust manifold…the air being allowed back into the coolant continually causes overheating but it will be randomly if it’s a small leak in the head gasket…

also, as much as I’m against adding anymore electric anything to these vehicles, in 5 years, I’ve changed outthe water pump 4x….it’s been the bearing that goes out so quickly..and the last one, the gasket turned to mush because of the dexcool antifreeze …the water pump was ok though…only thing that would cause the bearings to go out like this is from the fan being slightly off balance and putting stress on thetiny a$$ water pump it has…it’s almost comical….sounds like that might be something to help with the fan issue if u went electric fans instead…that huge fan attached to the Tiny water pump just doesn’t seem logical for lasting very long….
 

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'05 Chevy TB EXT
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Actually ... we did some gyroscopic stability tests on heavy fans verses lightweight fans on the GMPD-LMPD Liquid Nitrogen Conversion Vertical Stations when I worked at a cryogenics plant in Buena Park, CA.

They had failures of bearings - and remember that this was when the bearings of the US manufacturers were all going to stuff in The VietNam War and weren't available ... so bearing life was hypercritical.


The company (Paul Division of AIRCO Cryogenics - long gone by now since it was a NASA supplier) was making it's own bearings, so this was important to them.

What they found out was the bearings failed with the lightweight fans a lot more often because of harmonics - which the heavier fans didn't create so much even at decently high centrifugal loads from even relatively small unbalances.

The fans on our 4.2s are decently massive compared to "normal" fans on other engines - so I'm leaning on cheap-Chinesium bearings in 3rd World water pumps sold and bought for their discount prices being the biggest failure problem.
 

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2004 chevy trailblazer_lt
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Nice to know. Thanks!
 
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2004 chevy trailblazer_lt
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Get better and rest well!
 
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