6.0/4L80e swap running hot!

[ThunderBolt]

Well guys about a week ago I took the plunge and pulled the 5.3/4l60e out, only to replace it with a 6.0/4l80e. I stuck a TR Blower cam in for good measures and a week later it was finished. I topped all my fluids off then drove uptown only to realize that my coolant temperature sensor was bad. I got almost all the way home before it died on me and I had to push it a couple hundred feet into the driveway. Right before it shut off I heard a valvetrain noise which was probably due to the low oil pressure since my truck was running so hot; my truck was also steaming out the exhaust really bad. The next morning I pulled the coolant temp sensor and saw that no water came out (air bound?).. so I cranked the truck up until water started coming out the sensor port. I put the new coolant temp sensor in and filled the coolant up to its correct level. It was still steaming really bad out the exhaust so I went and bought a bottle of Blue Devil treatment that's meant for sealing head gaskets and warped heads. Well believe it or not the exhaust doesn't steam anymore!! It was about $65 for a bottle and it mixes with coolant unlike most sealants that you have to flush out after treating. I let it idle for about an hour and it was staying right around 210 degrees without the thermostat. I drove it probably five miles (still without the stat) before it started getting hot again. I pulled over to let it cool and once it was cool I made it all the way home just as the temp was starting to climb again. I then heard that our trucks won't stay cool without the thermostat so I put that back in. I disconnected the crossover tube at the radiator and started up the truck to get more air out of the cooling system and also make sure the water pump was working. Once the t-stat opened up water was spitting out decently so I filled the radiator and crossover tube back up and connected them. I drove it down the road only to find out it was getting hot again. I have no idea what it could be?? It seems my water pump is working and belt isn't slipping.. but it is almost like the coolant isn't circulating probably. I'm not sure where to go from here.

Thanks,
Trevor

[Wilde Racing]

I would be worried about the engine. if it actually quit on you thats not good. (like you didnt know that right? lol). sounds like there may be an air pocket in the cooling system. what type of fan are you using? how many miles on the rad?

[ThunderBolt]

I would be worried about the engine. if it actually quit on you thats not good. (like you didnt know that right? lol). sounds like there may be an air pocket in the cooling system. what type of fan are you using? how many miles on the rad?

Yeah, I'm worried about the engine. The radiator is a 34 inch I bought new last december when I put the 05 up truck e-fans on.

[Wilde Racing]

Are you sure both fans are coming on high? is the A/C on?

[ThunderBolt]

Yeah both fans are cycling right and when a/c is on the relay kicks them on high.

[r6z4o6]

I would never recommend a "stop leak" for a head gasket, much less anything else. Sounds like you need to invest in a compression tester my friend.

[pl4yboy]

I would check for air bubbles in the system.

[ThunderBolt]

I would never recommend a "stop leak" for a head gasket, much less anything else. Sounds like you need to invest in a compression tester my friend.

Well it's not exactly your conventional "stop leak".. Unlike most agents out there Blue Devil is a thin liquid that forms a chemical reaction with water when heated and creates a bonding gel that seals up leaks caused by blown head gaskets or warped heads(not sure if that's what happened). I've heard it used to be more of a commercial product and my dad used it in his isuzu box truck with great results so far. Even though it says it permanently seals, I'm sure results are temporary especially in a boosted application.

[pl4yboy]

I would check for air bubbles in the system...

[ThunderBolt]

I would check for air bubbles in the system...

I pulled the crossover tube off while running and air came out.. I put it back on but still feel like there's air in the system. A buddy that works at GM said that the best way to get air out is to vacuum the system but that requires a special tool or getting the dealership to do it. I think i might get a pvc pipe and install it in the middle of the crossover tube (since it's the highest point of the system) and make a pressure release valve into the pvc pipe.. I would keep the valve open until coolant is steady streaming out.

Anybody think this would work? Or know a better way to get air out?