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Coolant loss

2K views 6 replies 6 participants last post by  Z15 
#1 ·
loosing coolant but no visaul leakes, i have replaced the radiator over flow cap, which appeared to be visually deforemed at the top ( somewhat domed and extemely tight getting on and off) i dod notice tonight that there is some evidence that at some point there may have been leaging at the weep hole but im not sure if that offured last year when my radiator was pluged and i had and overheating issuse and the engine shut down, which has since been replaced.
I did a cylinder compression test 2 days ago on all 8 cylinders and had 150 psi on all cylinders, havnt done a copression test on cylinders in 20 years but i felt confident in my results. I called th edealer and asked what the preasure SHOULD beand they said 165 psi. im a tad concerned about the 15psi difference for such low milage, also been running MOBILE 1 synthetic since initial break-in.
I am getting the white smoke exhaust for a few miles till the engine gets to temp then it stops, exhaust doesnt have th esweet smell of antifreeze though!
anyone have input?
Thanks Tony
 
#3 ·
Certain years had cast tech heads that were prone to cracking. I had a set on my 05 Sierra. If you do a cylinder leakage test that will tell you if not pull your valve cover and see if it s slugged up or orangish in color also there is a battery looking symbol that how you know its a cast tech. Notice any chunkiness in your oil changes?
 
#5 ·
no signs of coolant in the oil, but i did notice this morning when the truck wouldnt start again that the coolant lvl in the overflow tank wasnt even visible any more, at that point the truck had sat for 11 hours, i then decided to remove the cap and the coolant lvl returned to where it was 5 days ago, approximately 4" rise in level. so it looks as though im not physically loosing coolant just excessive preasure causing it to look like its gone.
 
#6 ·
chevyman2k12 said:
Certain years had cast tech heads that were prone to cracking. I had a set on my 05 Sierra. If you do a cylinder leakage test that will tell you if not pull your valve cover and see if it s slugged up or orangish in color also there is a battery looking symbol that how you know its a cast tech. Notice any chunkiness in your oil changes?
What should a cylinder leakage test run at a dealer? They couldn't definitively tell me if 8 had castech heads...I told em look up image online beforehand if they were unsure.

Mine was a water pump when I had similar symptoms of coolant loss but no drips in the driveway.

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