Overheating Issue

[jhm2000]

A few weeks ago I was driving and I started smelling something, and I heard water like it was under the passenger floor area, I was sitting at a stoplight and the truck started overheating. I replaced the water pump and the thermostat, because no coolant was moving through, and it was still overheating, I was told by multiple coworkers who are mechanics to just bleed the system which I did and the problem persisted. I checked the thermostat with boiling hot water and it wouldn’t open, I changed it again, and I have bled the system multiple times. I have done multiple checks on the gasket, and nothing leads to a bad or cracked head gasket. I’m running around in circles, and I don’t know what else to do.

 

[Martins hemi]

Have you checked your radiator?
Hoses ?
Intake gasket?

 

[Curt Gobbell]

You need to confirm/deny a few things first.

1. While the engine is cold, confirm the coolant level is at the radiator cap
2. Start engine, with rad cap off and confirm coolant moves in radiator (you swill see air bubbles or small coolant flowing)
3. At the dash temp gauge reaches 190, watch the radiator coolant level (cap is still off) it should suck the coolant into the engine block (because the t-stat will open between 190f and 210f).

And report back on these 3 items above

 

[jhm2000]

You need to confirm/deny a few things first.

1. While the engine is cold, confirm the coolant level is at the radiator cap
2. Start engine, with rad cap off and confirm coolant moves in radiator (you swill see air bubbles or small coolant flowing)
3. At the dash temp gauge reaches 190, watch the radiator coolant level (cap is still off) it should suck the coolant into the engine block (because the t-stat will open between 190f and 210f).

And report back on these 3 items above

1. The level is at the radiator cap and there’s some in the overflow reservoir
2. Yes it does that
3. The coolant level does drop when temp starts to reach 190

Whenever I am bleeding the system for air bubbles, it starts to flow rapidly out of the open radiator once temp gets to about 210 unless I rev it up then the coolant level drops where I can replace the cap.

 

[jhm2000]

Have you checked your radiator?
Hoses ?
Intake gasket?

Yes I have checked all three, radiator is working as it should, hoses are secure and have no leaks, and no sign on intake gasket failing.

 

[Curt Gobbell]

Since everything above is working properly, you either have a) an air pocket in the coolant system or b) a blockage in the system.

I would a) remove the t-stat, b) disconnect the lower and upper rad hoses from the rad and c) put a garden hose in the lower rad hose then d) start engine and see if coolant flows forcefully from the top hose.

 

[jhm2000]

Since everything above is working properly, you either have a) an air pocket in the coolant system or b) a blockage in the system.

I would a) remove the t-stat, b) disconnect the lower and upper rad hoses from the rad and c) put a garden hose in the lower rad hose then d) start engine and see if coolant flows forcefully from the top hose.

I may try this tonight if I have time. Last night on the third time of bleeding the system. I had someone revving the truck up to about 2-3k RPM while I watched the levels with the cap off. All of the sudden once the truck got up to about 210 degrees, coolant began shooting out of the radiator. Pretty much all of the coolant. I stopped because the truck was smoking from the coolant hitting the hot engine. But what I’m wondering is could that have been the results of a blockage coming free? I’m hoping maybe that the blockage came free or a giant air bubble shot out when all of that happened last night. So I’m gonna fill it all back up tonight and see where I’m at.

 

[Curt Gobbell]

As long as you keep the garden hose in the lower rad hose you will be fine.

Once the tstat opens, coolant will shoot out of the upper hose because your water pump is pressurizing the system.