Hey guys. Newbie here. I have a 99 7.3 L than I have sunk a lot of money into - More for bulletproofing than racing but still pushing about 500 HP. If I baby it everything‘s fine but when I push it a little I lose antifreeze out of the degas cap which has been tested at 15 psi. I tested for exhaust gas in the degas bottle and there was no color change. The mechanic that built it seems to think the radiator is restricted. Of course he’s trying to get out of doing any warranty work. He put a larger pulley on the harmonic balancer which would make everything speed up I would think including water pump. Would that push too much pressure.? Motor runs great pushing about 47 lbs boost But when I get home I have to refill the radiator. Any ideas? Still need to do a transmission upgrade after I get this problem fixed

 

Your mechanic sounds pretty shady to me. What mods does that engine have? Injectors, turbo, exhaust, intake upgrades programmer (type and setting) etc. We need more info for sure. Bigger Harmonic balancer pulley????

 

It has stage one injectors with a chip that came with the injectors and it is adjustable, whole setter turbo, Crower rods, Stock pistons that have been ceramic coated, cometic head gaskets, ARP head studs and main studs ,4 inch exhaust, AFE intake, Upgraded valve springs. The larger harmonic balancer pulley was to help with hard steering issue at idle on these trucks