6.0/4L80e swap running hot!

[pl4yboy]

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?

Fill it to the top with coolant with the vehicle running. The air bubble will likely end up in the crossover. Squeeze the crossover in a pumping manner until the bubble is pumped out. Keep filling the system as it runs down. EVENTUALLY, the bubble will come out.

[RedHeartbeat]

park it on a hill, engine off, with the front end higher than the rear, take the air bleed hose off, remove the upper radiator hose from the radiator, pour water into the hose until a steady stream of coolant comes out of the air bleed hose fitting on the engine side. Reconnect everything.

[LsxCody]

Hope u get everything right

[GasGuzzler]

You need an air lift...yes, what we have at the dealer. Then again, it's prolly hurt.

[ThunderBolt]

Fill it to the top with coolant with the vehicle running. The air bubble will likely end up in the crossover. Squeeze the crossover in a pumping manner until the bubble is pumped out. Keep filling the system as it runs down. EVENTUALLY, the bubble will come out.

park it on a hill, engine off, with the front end higher than the rear, take the air bleed hose off, remove the upper radiator hose from the radiator, pour water into the hose until a steady stream of coolant comes out of the air bleed hose fitting on the engine side. Reconnect everything.

I tried both of these methods but it's still overheating. I even found a good article about the GM coolant fill procedures which RedHeartbeat was describing.. We've had complaints of overheating on some late model GM truck engines; any clue why this is happening?: Engine Builder

I'm going to take the water pump off and check it out; something tells me there is something blocking my water passages not letting it circulate properly.

[ThunderBolt]

I just took the water pump off to inspect it and everything looked okay, and there was nothing blocking the water passages. Just to be on the safe side I put the water pump off of the 5.3 on because I knew that it worked but still no luck. This truck just won't stay cool!!

[Trick1]

How hot is it getting. 220 230 240? If the truck only gets hot while driving sound like the engine has issues. The fact that it got so hot it died says it most have been really hot.
Does the truck smoke any after it cools down and you restart it.?

[ThunderBolt]

How hot is it getting. 220 230 240? If the truck only gets hot while driving sound like the engine has issues. The fact that it got so hot it died says it most have been really hot.
Does the truck smoke any after it cools down and you restart it.?

First time when it died the coolant temp sensor wasn't working, so it had to get really hot and I didn't even know it. It did steam a lot until I put the Blue Devil treatment in. Motor doesn't steam out exhaust anymore but it does steam a little out of the valve covers.. feels a little rough to me but maybe its the cam. It will get as hot as you will let it, although I shut it off when it gets around 230.

[r6z4o6]

Compression test your cylinders first.
Are your fans turning the right direction?
Any water in your oil?

I don't think it's air bubbles.
That may have been it in the beginning, but i'm going to say you have a multiple problems now. You have an even BIGGER problem with the engine, yet you haven't tried to figure out what could have happened when it got so hot that it turned itself off. You sure are working hard at getting an airbubble out to fix it all, but.....

Seriously though, running rough, overheats, and steam out the valve covers? Does that really sound like an air bubble to you, or are you just avoiding the possibility of headgasket or worse in the hopes that it will go away?

I am not trying to be an a$$. Steamy exhaust and valve cover are not symptoms of "air bubble." I think you know what it is, so why not look into that? The Blue Devil is just making you feel better about a problem it can't permanently fix.

[ThunderBolt]

Compression test your cylinders first.
Are your fans turning the right direction?
Any water in your oil?

I don't think it's air bubbles.
That may have been it in the beginning, but i'm going to say you have a multiple problems now. You have an even BIGGER problem with the engine, yet you haven't tried to figure out what could have happened when it got so hot that it turned itself off. You sure are working hard at getting an airbubble out to fix it all, but.....

Seriously though, running rough, overheats, and steam out the valve covers? Does that really sound like an air bubble to you, or are you just avoiding the possibility of headgasket or worse in the hopes that it will go away?

I am not trying to be an a$$. Steamy exhaust and valve cover are not symptoms of "air bubble." I think you know what it is, so why not look into that? The Blue Devil is just making you feel better about a problem it can't permanently fix.

Fans are turning in the correct direction and there isn't any water in the oil. I'm convinced that air was in the system at first and that's why it ran really hot.. also the malfunctioning coolant temp sensor which is why I didn't realize it was hot at first. The first time when it ran really hot it had to damage the headgasket or warp the head.. I mean the oil was so hot it was barely holding oil pressure resulting in valvetrain noise. It didn't run very long like that so hopefully nothing is damaged internally. The Blue Devil did stop it from steaming out the exhaust; however, I know that it cannot permanently fix the problems I have. I'm hoping that it will only take a couple of head gaskets to fix instead of the heads being warped. Wouldn't you say the gaskets would blow or burnout before the heads would be warped? And if the heads were warped, wouldn't you think the motor would skip more than being just a little rough?