Chevy and GMC Duramax Diesel Forum banner
Cancel
Create thread New Garage Forums

Coolant Leak Drivers Side Rear of Engine

Jump to Latest
9.9K views 5 replies 2 participants last post by  long-time-dmax  
#1 ·
Hey folks, as the title suggests, I’ve got a coolant leak going on. When I pressurize it with my tester, it shows up as a slow drip off of the oil filter housing on the drivers side of the truck. It is coming from somewhere above that though, but I can’t seem to get a good enough look to find where. Only found this because I had a cracked quick connect at the heater core on the firewall, so after replacing those I pressure tested to make sure there were no leaks after the fix. The heater hoses were fine, but this other leak showed up.
Any suggestions on where it could be coming from? I am planning on taking things apart tomorrow to get to the turbo cooling lines to see what condition they are in. But from searching old threads, it seems when those leak it is a large leak rather than slow dripping. I suppose at over 330k miles it could be a head gasket, but I am certainly hoping not. Thanks in advance for any further suggestions on where to look.
 
#3 ·
Thanks, one more thing to check on. I didn’t even know there was an oil cooler tied in up there. Any tips on what to take apart to get a proper look? Looks like the wiring harness and inter cooler piping would be first things to get out of the way.
 
#4 ·
It's just really hard to see. I took mine apart on a guess and a prayer that that was what was leaking. Even after I got it apart and saw that one side of the gasket was really smashed, I still wasn't absolutely sure that was the leak until a week or so after putting it back together and no more leak..

It's not especially hard or expensive to replace the gasket. You will also need the gasket for the tube that goes from the oil cooler to the back of the water pump (housing). You have to disconnect it from the water pump housing. The tube is actually just part of the cooler.
 
Save
Reply Quote Like Like
#5 ·
Well that was fun. Turned out to be the hose clamps on the turbo cooling lines that had worked their way loose over time. If it happens again, I’ll replace the worm drive clamps with some other type. Been holding rock solid at 15 psi for about 2 hours now. Calling it good and will put it back together shortly.
Image
 
Chevy and GMC Duramax Diesel Forum
posts
3.9M
members
230K
Since
2005
A forum community dedicated to Chevy and GMC Duramax diesel owners and enthusiasts. Come join the discussion about modifications, towing, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Discussions 01-04.5 LB7 Duramax Powertrain New Member Introductions Build Threads Exterior