ethanfurniss

You might think I'm tossing you a slow pitch soft ball but sadly I don't think that's the case.

TRUCK:
1994 P/U 4X4 22-RE Manual transmission

PROBLEM: Over pressurization of cooling system
The cooling system runs at about 17psi. This problem has progressed over the past 2+ years. I can still drive around town but sustained periods (>20minutes) on the freeway cause a coolant loss substantial enough for overheating to occur.

TROUBLESHOOTING:
Block test (multiple tests- always passes. Then I test the tester at the exhaust pipe)
New OEM water pump
New OEM fan clutch
Multiple New thermostats including OEM
1/8" hole drilled in thermostat
Multiple New radiator caps 13psi (all tested of course)
New Radiator (no cold spots found with infrared thermometer)
Bypassed heater core
Compression test (170psi holding for >10 minutes)
Cooling system pressure test (holds 20 psi for >10 minutes)
Coolant flows below radiator cap. No bubbling visible.
Cooling system burped.

HISTORY:
I blew a head gasket about 3 years ago. I used all OEM gaskets and head bolts and had the head pressure tested and decked at that time. Truck ran fine.
I broke a valve spring about 2 years ago in May 2022. I used all OEM gaskets and 22RE Performance 65lb valve springs, retainers and keepers. And I had the head pressure tested and decked at that time. The first low coolant event happened in October 2022 and has gotten worse since then. I can't drive on the freeway any more but I can drive around town without event.

NOTES:
The block was pitted at the deck every time I took the head off. It's counter intuitive but no-one (repair shops, machine shops...) said this would be a problem. I'm second guessing that.
I haven't tried opening the block plug by the bell housing and irrigating the water jacket.

CONCLUSION:
I'm ˟˟˟˟.
Maybe I'm missing something.
Should I do head gasket again but take the head to a different shop for pressure testing and machine work?
Should I rebuild my long block so I can get rid of the pitting on the deck and double check the head?

Money and time are an issue. If they weren't I'd be posting in the TDI swap section.

Thanks for your help guys. This forum is great.

ethanfurniss

Sorry for the redundant post. I'm still scratching my head with this.

osv

"block test"? as in a combustion leak test at the radiator cap? fwiw, i think that it would only test for the presence of exhaust gas, see other options here: https://www.2carpros.com/articles/he...ket-blown-test

so where is the coolant actually being lost? sounds like back out the radiator cap and into the overflow when the engine gets hot? not out the tailpipe?