Yesterday, with a new stant radiator cap, there was no pressure under the cap after a 1 h 10 minute drive..... none.
I can purchase more caps to test this variable but considering I already went through this with my other CRD's when they had HG leak problems, I don't think I will. Surely one of the brand new caps on my shelf has to be OK, not all of them could be defective.
Or are you suggesting that all 3 caps should be considered bad and procure a few more and test them just to be sure?
This vehicle has never experienced pressure under the cap since the day it was purchased no matter how long the drive or how high the temperature reached, until three weeks ago.
Last month, for the duration of 2 to 3 weeks the pressure that I felt under the cap was explosive, this observation happened immediately after driving 30 miles and then tested many more times after that on short trips, long trips, medium long trips, within a three week span, the pressure under the cap was explosive.
I also performed the one minute pressure under the cap test and it was positive for pressure under the cap, indicative that there is a HG leak.
But now, for the past 5 days the system is no longer experiencing explosive pressure under the cap, no matter how long the trip is and no matter how high the engine temp reaches.
The one minute pressure under the cap test shows no pressure escaping and there is no coolant loss.
Other LOSTKJS CRD owners have indicated that their CRD's have also never experienced pressure under the cap, same as I have.
I am wondering if the following could be happening:
1. Is the aluminum head at the beginning stages of deforming, allowing gasses to escape through the HG and then retracting back to it's original shape sealing the leak? I think of it as a pulsation during the high and low temps.
2. Could this be the beginning stages of the head warping, or head bolts stretching past the acceptable limit and remaining in that position no longer capable of clamping the head down properly, allowing coolant to pass through and deforming the HG by creating rust? My Head gaskets were very rusty when removed, we found particles of rust imbedded into the aluminum head creating craters that trashed the head.
3. Could ambient temperature be a factor?
Weak thoughts.... possibly, but what is happening here?
I know nothing about metallurgy so if someone does, then please shed some light, I would appreciate it.
Today, I will have my laser temperature gun with me and I plan to record the engine temps as requested.
_________________ 2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster" 2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket" 1982 Fiat 124 Spider Convertible. "Fiona"
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