3B oil/coolant leak (1 Viewer)

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Need some advice. My 3B sh*t the bed and I'm trying to figure out why there's oil coming out the block about halfway down as seen in the photo (the stuff above was from me spilling a bit🫤) pretty sure it's a head gasket but and just wanting to see if there's any other things it could be. About a week ago it lost oil preasure and there was black gunk in the coolant (not sure if it was oil) so I flushed the radiatior and filled with oil and all seemed fine. Then about a week later I took it for a drive (80kms) and about 36 odd hours later theres coolant and oil coming from that was I assume is an breather pipe.

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It’s probably your oil cooler.


The oil cooler is in a aluminum housing that fills with coolant, then oil passes through a tube that connects in the area that’s circled in red.

Basically oil and coolant come in VERY close contact - if the seal/O-ring go bad, you can have the two fluids mixing- good gaskets are crucial.


Did you do a leak down test?

Perhaps you have a blow head gasket that is allowing excessive combustion chamber pressure into your oiling/cooling system that is blowing the gasket.

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I'm looking at getting a gasket set you reckon it would come with a oil cooler O-ring/gasket

What's a leak down test?
 
I'm looking at getting a gasket set you reckon it would come with a oil cooler O-ring/gasket

What's a leak down test?


If you buy a gasket set for the whole engine, it most likely will. Mine did at least. It’s nice having every gasket even if you don’t need it.

A leak down test will indicate if you have ANY exhaust gasses in your cooling system.

If you buy the tester kit, there is a tube that sits on top of your radiator- this tube will have blue fluid in it- if you have ANY exhaust gasses in the system it will turn green, indicating a blown head gasket.


Before you do that, take the radiator cap off when the engine is COOL- then start It up without the cap on…. If you have a serious blown head gasket, you will see bubbling in the radiator cap.

Hope this makes sense.
 
looks like your blowby tube coming off of the pushrod cover, could be excessive blowby from bad cylinder rings (potential engine rebuild)
could be head gasket
could be the seal around the pushrod cover needs resealing
might be oil cooler related... especially if there is coolant too
 
I have a 1980 BJ40 with a "rebuilt" 3B diesel. I ve had it for 1 1/2 years with about 5600kms on it. I have fixed a parking brake transfer case oil leak and looks like the rear crank oil seal is also leaking. I have done a compression check with 500-600 psi readings. Blow back looks normal but my mechanic has filled the lubrication system over the "full" line by about an inch. I think he did this because of the rear crank seal leak because he doesn't want to drop the transmission/ transfer case to replace the seal. I have what looks like an oil substance on the side walls of the coolant expansion tank but don't see any oil slicks on the coolant when I open the radiator cap. I do have a few oil leaks underneath the truck. I'm wondering if I should flush the cooling system with a degreaser solution and fill with new coolant to see if I still get this grit on the walls of the expansion tank.
 
yes flush the cooling system, replace the oil to the correct level (overfilled oil is bad for multiple reasons, clean the expansion tank and monitor it.
If the head gasket is going you will see bubbles out the expansion tank fill tube (before the coolant is hot and pressurized itself)
this is the combustion gassing pushing past somewhere.
I would clean all the oil leak areas and monitor them as well to isolate the issue
 
yes flush the cooling system, replace the oil to the correct level (overfilled oil is bad for multiple reasons, clean the expansion tank and monitor it.
If the head gasket is going you will see bubbles out the expansion tank fill tube (before the coolant is hot and pressurized itself)
this is the combustion gassing pushing past somewhere.
I would clean all the oil leak areas and monitor them as well to isolate the issue
Thanks. I'll try the flush. If I had a leaking head gasket wouldn't the compression be low?
 
hard to say,
it could be the oil cooler i guess too
 
hard to say,
it could be the oil cooler i guess too
I heated the engine up and detached the hose from the expansion tank ( that runs from the radiator cap) and inserted the end of the hose into a bottle of water to see if I got any bubbles or discharge and didn't. Given this and the compression test results I don't think I have a leaking head gasket. I'll try the flush and see what happens. Thanks/ Chuck
 

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