LLY Rear Engine Coolant Leak


New member
Mar 11, 2022
Maybe been posted 100 times, just hoping for a guardian angel before jumping to head gaskets.

Started with a weeping water pump, I replaced that. A few weeks after the short egr cooler hose busted. Replaced that. I now have a coolant leak on the rear engine, seemingly engine to bell housing.

I’ve checked the turbo coolant line and U shaped hose, all dry. Around the mount of the cooling plate seemed dry but the bellhousing above and below is soaked. It’s a steady leak even when the engine is off.

My initial thought is the rear o rings on the rear engine plate. But it seems pretty coincidental that one offer the other coolant hoses/rings keep leaking. When I pulled the downpipe, I did notice seepage down the back of the head. Not wet, but seeping for sure. Heater core lines are dry as can be as well.

Any other hoses I’m missing that might be causing my issue you guys can think of? Upper rad hose is still soft after a operating temp/overnight park. Hoping to not have to break into this truck since I already have a project truck in the garage. Thanks guys


New member
Mar 10, 2023
For the benefit of others, I had the same issue. It turned out to be the coolant line to the turbo. I hope this helps someone.
Me too, I overlooked it the first time, it was running under the hose where you couldn't see and then dripping down onto the bell housing.


Well-known member
Jun 23, 2009
TX of course
If it's leaking after it shut off I really doubt it's a head gasket. It's pretty rare to have an external coolant leak even with blown head gaskets unless it's blowing out the overflow vent. Letalone a leak with the engine off.

Never mind I didn't realize how old the original post was.