Excavator overheats,Air bubbles in cooling system

[Mike123]

Hi
I have a Kubota kx080 2018 that overheats after a couple hours. there is air bubble in cooling system as soon as I start the engine and that air pushes out the antifreeze in cooling system.
after a couple of hours and excavator overheats. excavator runs and function as a should.No smokes and no oil and coolant mix.
what are my chances this to be only head gasket and not the head or block? Engine is V3307-CR-T-EF06. Is there any possibility that EGR is faulty and pushes exhaust gases into the cooling system?

 

[Tx Jim]

Welcome to this forum
Sounds as if head gasket &/or cylinder head is faulty. One could test radiator operating pressure with a gauge. Remove cylinder head & have it magnafluxed checking for cracks & have machine shop check it to be sure it's level. Have you got engine above normal operating temperature lately?

 

[William1]

Yup, head gasket. There are testers for check for combustion gases in the radiator/coolant that will confirm it.,

 

[Flintknapper]

Classic blown headgasket symptom (as you already know), but could also be a cracked head.

So....only by removing the head and having it inspected will you know.

Hopefully, it will just be a headgasket for you. But running the engine hot increases the chance of further damage (warped/cracked head).

 

[BT3101]

NAPA offers a test kit:

Leak Detector Kit / Engine Block Test Tools Inc. BK 7001006 | Buy Online - NAPA Auto Parts

 

[Flintknapper]

IF you have immediate and consistent bubbles upon start up (looking into the radiator with cap off), then you can skip the exhaust gas test kit. There is really only one viable reason for that.

 

[Mike123]

Thank you all for reply.
How many hours or how much work is it to replace the head gasket on this engine in the field.is there a video that shows the procedures on this engine or excavator?

 

[Mike123]

Welcome to this forum
Sounds as if head gasket &/or cylinder head is faulty. One could test radiator operating pressure with a gauge. Remove cylinder head & have it magnafluxed checking for cracks & have machine shop check it to be sure it's level. Have you got engine above normal operating temperature lately?

Hi
I just bought the machine few days ago and it will work normally for 2-3 hours until the coolant gets pushed out and then temperature rises.I never let it go to the red but I don't know what happened in the past.

 

[Mike123]

IF you have immediate and consistent bubbles upon start up (looking into the radiator with cap off), then you can skip the exhaust gas test kit. There is really only one viable reason for that.

Hi
It is immediate and consistent. it's not a lot so machine will work for 2-3 hours but you can easily see it if you fill up the radiator to the top I even bypass the EGR cooler for just the test and is definitely is not from EGR either.

 

[Flintknapper]

Hi
It is immediate and consistent. it's not a lot so machine will work for 2-3 hours but you can easily see it if you fill up the radiator to the top I even bypass the EGR cooler for just the test and is definitely is not from EGR either.

Sounds like your machine is being 'courteous' and warning you of an
impending 'full blown' HG/Head failure.

I'm sure you are aware the headgasket itself can fail in more than one way, though it sounds as if yours is letting exhaust gas get into the cooling system.