cooling issues

[1009er]

my 1009 is having issues with cooling. a little background. within the past year it has a new heater core, radiator, all new hoses and a good couple flushes. had an issue the other day when I got home the low coolant light and just come on. I shut the truck off it sounded like the coolant was boiling. opened the hood and it was bubbling but not hot like something was under pressure and blowing the air back to it. checked things out. had plenty of coolant, had pressure still in the top radiator hose, and nothing was really leaking. assumed it was the thermostat. changed it out and still does the same thing. tonight when I get home I will pull the thermostat out and try it without it in there. I feel like the water pump is working because its building pressure. Anyone have any other ideas to check out???? I've talked to a few guys and checked online but nothing seems to be what I have going on. one guy said he had an issue like this and all of his ports in the block were clogged. I feel like I would have a clog somewhere else since it just started suddenly. I've been doing a bunch of work to the truck lately and feel like I would hear a little bubbling if that were the case and it would happen over time. I'm lost if taking the thermostat out doesn't work....

 

[3jumpjeep]

my 1009 is having issues with cooling. a little background. within the past year it has a new heater core, radiator, all new hoses and a good couple flushes. had an issue the other day when I got home the low coolant light and just come on. I shut the truck off it sounded like the coolant was boiling. opened the hood and it was bubbling but not hot like something was under pressure and blowing the air back to it. checked things out. had plenty of coolant, had pressure still in the top radiator hose, and nothing was really leaking. assumed it was the thermostat. changed it out and still does the same thing. tonight when I get home I will pull the thermostat out and try it without it in there. I feel like the water pump is working because its building pressure. Anyone have any other ideas to check out???? I've talked to a few guys and checked online but nothing seems to be what I have going on. one guy said he had an issue like this and all of his ports in the block were clogged. I feel like I would have a clog somewhere else since it just started suddenly. I've been doing a bunch of work to the truck lately and feel like I would hear a little bubbling if that were the case and it would happen over time. I'm lost if taking the thermostat out doesn't work....

Boiling coolant makes pressure. The pump moves the coolant through the radiator so it doesn't boil. I'm thinking pump isn't moving enough coolant. How's the fan clutch? I had to replace mine a couple years ago.

Sent from my SCH-I545 using Tapatalk

 

[1009er]

Boiling coolant makes pressure. The pump moves the coolant through the radiator so it doesn't boil. I'm thinking pump isn't moving enough coolant. How's the fan clutch? I had to replace mine a couple years ago.

reading back through I forgot an important part. when I started it back up after installing the thermostat it was bubbling instantly as soon as I went from the cab to the engine bay

 

[Bighorn]

reading back through I forgot an important part. when I started it back up after installing the thermostat it was bubbling instantly as soon as I went from the cab to the engine bay

I hate to say this but if you are getting bubbles from a cold engine, you may have a head gasket leak.
Let it cool completely and pop the radiator cap.
Start it up and observe the opening of the radiator.
A lot of air coming out meaning combustion gasses are getting past the head gasket (or someplace else but most likely the gasket) into the water jacket and finding their way up and out the radiator cap.
It can do this and not lose water.
You could find the problem with a leak down test.
It involves putting compressed air into the cylinders one at a time, while each is at top dead center in turn, and observing leakage.
It is actually a tricky thing to do and you can hurt yourself if you've never down one.
Adding compressed air to a cylinder that is not exactly at TDC pushes the piston down violently and fingers or clothing can get caught in belts etc.
Compression test is safer but might not show the leak as distinctively.
On these engines you use the glow plug holes to fit a compression tester or an air source in the case of leak down testing.
There are also test kits that look for leaking exhaust gasses in the coolant chemically.

 

[Drock]

Sorry but it's a head gasket. It will slowly get worse, pushing brown, contaminated, coolant out into the recovery tank. I drove my M1028 for a year until it couldn't take it any more. I got really good at taking the recovery tank off and refiling the radiator every morning.

 

[dmetalmiki]

As mentioned above. Compression gasses are escaping in to the cooling system. If they get bad enough (and you should already observe) The hoses 'swelling up' when the engine runs. Some "sealers2 purport to 'fix' any leak anywhere. But surely just a stop gap. Let us know when you carry out the remedial work on the problem and it's fix, With pictures if possible..

 

[TGP (IL)]

reading back through I forgot an important part. when I started it back up after installing the thermostat it was bubbling instantly as soon as I went from the cab to the engine bay

Yup.
As they said.
Heads need to come off, get checked and new gaskets.
Tom

 

[cucvrus]

https://www.steelsoldiers.com/showthread.php?137671-CUCV-head-gasket-head-or-change-engine-survey

This might help you. I have done a few head gaskets in the past 5 years. basically they just need changed from age. Good Luck. get the heads checked and machined at a reputable shop or you are just wasting your time. I had 3 sets of heads on the same job that were cracked. Ask questions. No questions are dumb. Except them that are not asked.

 

[1009er]

sorry for the delay. ive been out of town. last night I finally had time to take the thermostat out and run it. the thermostat was a bad one out of the box. I do have flow back to the engine now but it is still bubbling. after more research I'm pretty sure it is the HG. This oughtta be fun! I know the basics of it but I've never done one. any pro tips? I don't know when I'll get time to do it but when I do I'll do a full write up with pictures.

 

[MarcusOReallyus]

Know for sure, before you turn any wrenches.

 

[Bighorn]

Buy a pack of razor blades.
Solo cups and baggies and a sharpie pen.
Label everything you remove.
Torque wrench.
Set of head bolts.
Head gaskets.
Timing cover gaskets/top end kit.
Contact a local machine shop and let them know you need your heads checked out.
Don't skip that step.
Have them check those heads for; flatness, cracks, Valve seat issues.
It will be fun.
Personally, I think the reward is doing it yourself.

 

[Tinstar]

Use the best parts you can afford.
It does make a difference and that’s a job you don’t want to do twice.