So my cousin 1_BigMoFo who has an 2004 F250 SD CC 6.0L ARP Studs, black onx HG's, FCD EGR delete, Banks CAI, Intake Elbow, turbo drain upgrade, cooling mod, Fumoto, Full MBRP, SCT X3 - Innovative tunes, 7 ISSPRO gauges is having overheating problems. Seems it over heats when coolant gets low but coolant is constantly getting pushed out degas bottle.

Friday i stopped over, ran truck to normal operating tem, about 193*, than installed threaded stant adaptor on degas bottle and installed my stant coolant tester, with the truck idleing pressure guage went from 0 to 35 psi where it blew relief vavle on tester. relieved all pressure and again as soon as valve was closed the system began to rapidly build pressure. coolant has faint diesel exhaust smell. Took coolant sample to test for combustion and sent oil sample out figuering if their was a cracked head or leaky gasket it would show some antifreeze in oil. He said he gets white smoke on some morning starts and last for a few min on his initional drive away.

Throwing feelers out but sounds like cracked head or blown gaskets. just put Black onx gaskets and arp studs on it after having heads decked this past fall. problem was tuner disabled cooling fan operation and truck overheated on a few ocations this spring while towing.

 

Sounds like your headed on the right track. There have been lots of cases where black onyx gaskets failed. Whitch is why I recommend sticking with the oem gaskets. Were the heads checked for cracks and flatness when the job was done the first time.

 

Sounds like sombody has a head gasket job in the near future......

 

before i go towards the blown head gaskets, i'd check the egr cooler and oil cooler first. usually if one goes, then its time to change the other as well. common probs of the 6.0

its a common misconception when everyone defaults to the head gaskets at first opportunity. remember the white smoke? usually means u got coolant in the egr valve. might be the egr cooler failing. also, check the egr valve as well. if the spring is worn out, it might be more economical for u to replace the entire egr valve as well. safety first.

 

Not a fan of the black onyx gaskets....

 

You can check...but I'd be amazed that it would be so backed up to cause 35psi and not rupture the egr cooler into the exhaust....

what's the EOT to ECT spread?

 

if i aint mistaken, the spread is rather minimal, like about 15 degrees difference between EOT & ECT.

 

Yea the spread threshold is 15 degrees...

I was asking the OP what his buddy's ECT to EOT spread is....

 

Truck has full first coast diesel egr delete, that has all egr opening tig welded shut and molded coolant hose. Oil cooler is a year or so old, was rebiult when egr was deleted in want to say may of 2010.



ECT to EOT spread was aroung 3-5* no load, even under load while tune was keeping may around 10*

 

The heads were checked for crackes and he had then decked to ensure flatness.

 

Never meant to put the coolant system under that much pressure, put guage on truck, started truck and got busy for a min talking with my cousin and then jumped a mile when i heard the relief valve pop and seen the guage spiked just over 30 psi.

I after relieving pressure and watching it build again, i shut truck off with cooling system at 25psi, let it sit for a few min, saw small drop in pressure, fired truck up and saw a faint white puff of smoke. Thinking the 25psi pushed some coolant in to the bad cylinder.

Still waiting for oil sample, guessing if truck gets shut down with coolant system under pressure and it sits, if their is a leak their should be some sign of coolant in oil.

 

I put all my oreo's on the gaskets.....sorry man...bummer..

 

towing with a tunner is not always a good idea. always tow as close to stock as you can get

 

I remember 1BIGMOFO are you cousin Pete

seems like you guys did all that work and then around the first of the summer he found out his tunner was not turning the fan on and he had overheat and little puke issues

so the tunner may have warped the heads with the overheat

That sucks I thought he took the tunner off and all was good

good luck with it

 

That's excellent advice. EGT's aren't the only concern when towing tuned. High cylinder pressures, which you can't easily monitor, can be very destructive. An aggressive tune will have advanced injector timing and increased pulse width. If you have a heavy load, CP's can get above levels the tuner didn't anticipate, and wouldn't allow.