I just recently had my HGs replaced along with ARP studs on my 6.4. Invoice for completion was 1/21/14. HGs were replaced around 50k and it is near 53k now. $800 dollars in head work, they were supposedly checked and machined.
The truck is still puking:
I have tested two different caps to hold 16 psi (Stant and Motorcraft).
It has a brand new Mishimoto all aluminum rad b/c the last one would leak when it got near 0F outside.
Brand new thermostats, old ones were pulled to check for hyperextention, no issues with old or new.
Cooling system will hold pressure cold but not warm.
Put a pressure gauge on the cooling system 3/9/14. Went for a ride. No heat until ECT hit around 200, dropped back down to normal operating temp. Deltas are good. Got out on highway and let it rip in OD with the converter locked. Sure enough the pressure gauge jumps quickly from around 11 psi to 20 psi. Lost heat when this happened momentarily, then it came right back. ECT and EOT only jump about 8 degrees and the deltas still stay close.
I know this all points to blown HGs which were just done less than 3k ago.
The ONLY last shred of hope I have is a bad water pump causing pressure spikes but it all points to HGs.
Just looking for some advice on how to deal with the shop. The shop that did them are a very reputable shop in SW PA (they did tho mix gold coolant with the little bit of ELC left over in the block). I have called them already and said the truck was still puking, the response was bring it in we'll test the cap.
I mentioned the new rad and checking the T-stats and then they seemed worried. I didn't mention the pressure gauge b/c at the time I had yet to do it. They seemed very willing to look at it again.
I won't mention the shop name yet b/c as of right now I do sincerely believe that they will stand behind their work.
I really want to just come unglued b/c over $5100 later, the truck is no different than when they got ahold of it. For that amount of money and not having my truck for something like 10 days, I should not be even thinking of this situation right now. Rant over
But if anyone has come across a situation like this and would like to share what they found out, please do. I'm trying to cover all possible causes to my problem so that a solution can be found quickly and inexpensively.
Thanks in advance.
Truck is deleted, no EGR system left at all, Gearhead Tunes MCC based on H&S