Oil cooler gasket replacement

[Hey you]

I have had a small oil leak for the past year, maybe one or two drops a month. I do see some oil around the filter and the block off plate above.
Thinking of pulling the block off plate and replacing the gasket. Is it necessary to drain the oil first before removing the plate?
Last work I did on this Tahoe, was replacing the coils, wires and plugs, as there had been a misfire. Initially I thought the problem was transmission
related, and changed the tranny fluid, filter too. At the same time, I also removed the temp sensor, which now allows the transmission temp to run
about 30 to 50 degrees cooler than before . Truck is running great... and I like it. Just would like to eliminate this minor leak.
Thanks again for all the info from this forum...
You guys are Gr8!

 

[SpareParts]

No, but you will lose a couple cups, so be ready. I never had any luck with the sealing using the GM metal gasket. I use the felpro one and coat each side lightly with The Right Stuff.

 

[2017sltXL]

I have had a small oil leak for the past year, maybe one or two drops a month. I do see some oil around the filter and the block off plate above.
Thinking of pulling the block off plate and replacing the gasket. Is it necessary to drain the oil first before removing the plate?
Last work I did on this Tahoe, was replacing the coils, wires and plugs, as there had been a misfire. Initially I thought the problem was transmission
related, and changed the tranny fluid, filter too. At the same time, I also removed the temp sensor, which now allows the transmission temp to run
about 30 to 50 degrees cooler than before . Truck is running great... and I like it. Just would like to eliminate this minor leak.
Thanks again for all the info from this forum...
You guys are Gr8!

Good call on the t-stat. High temps have led to early deaths of many a transmission in these trucks.

No, but you will lose a couple cups, so be ready. I never had any luck with the sealing using the GM metal gasket. I use the felpro one and coat each side lightly with The Right Stuff.

I used the GM metal gasket once when I had an '01 Yukon. Never again...

 

[Hey you]

I got the Fel-Pro, just hope it fits OK.

 

[Geotrash]

I got the Fel-Pro, just hope it fits OK.

Watch the torque spec. It's a small diameter bolt into aluminum so it won't survive being over-torqued. And you don't want to be down there trying to get a Heli-coil in there. Don't ask me how I know.

 

[Hey you]

I do not have a torque wrench that small. What should the torque be? I usually use the snug plus 1/4 turn procedure!
Might need to visit HFT again, my favorite tool store.

 

[Geotrash]

I do not have a torque wrench that small. What should the torque be? I usually use the snug plus 1/4 turn procedure!
Might need to visit HFT again, my favorite tool store.

The torque spec is 80 INCH-pounds. I just double-checked with Alldata to make sure.

 

[West 1]

So by feel, 80 inch pounds is about 6.6 ft pounds of torque. If you were using a 12" wrench that would be 6.6 pounds of pressure applied to the end of your 12" wrench to make it turn. Not very much. I torque them by hand knowing it is aluminum and have had no issue but I have torqued hundreds of parts using the inch pound or ft pound torque wrenches so I at least have a good idea what 80 inch pounds feels like.

I like the idea of using the Right Stuff, a thin coat on each side of the gasket, it has to be thin because any extra might end up going into your oil pump making future problems.

Lately I have started using 2 of the Fel Pro gaskets rather than one and on the two trucks I did this on the leak was gone. This was a cheaper option to stop the leak.

 

[Hey you]

Looked under the hoe today to check on the leakage... now I see that there is an oil cooler installed, with the two lines going forward.
Actually, that mounting seems quite dry, and the only oil leakage seems from the rear oil pan bolts, and the cover to the rear main seal.
I will check the torque on the oil pan bolts first. Hope that cures the problem... but if it is the rear main seal??? Hope that is not the problem.

 

[Geotrash]

Looked under the hoe today to check on the leakage... now I see that there is an oil cooler installed, with the two lines going forward.
Actually, that mounting seems quite dry, and the only oil leakage seems from the rear oil pan bolts, and the cover to the rear main seal.
I will check the torque on the oil pan bolts first. Hope that cures the problem... but if it is the rear main seal??? Hope that is not the problem.

Probably the weakest point in the fluid sealing strategy of the LS/LT engines is at each of the 4 corners of the oil pan. There are three sealing surfaces that meet at each one, such that it requires a dab of RTV to ensure a reliable seal. That works great in the factory where the surfaces are clean and dry, proper parts alignment and cure times are assured, and the parts are new with new tolerances. In the field though, when you're working on jack stands with barely enough clearance to get the pan on, oily parts, and distortions in the tolerances from years of heat cycling, and you just want to get it back together, it's almost impossible to get those things to seal right. If that pan has ever been off, I can practically guarantee that it will leak in at least one of those corners, if not all four.

 

[Hey you]

Thanks for that info. I think I will first try to check the torque on the bolts I can access, and snug up if needed. Give it a good cleaning then
monitor. When I get that done, I will post again the results. Keeping fingers crossed!!!

 

[Hey you]

OK, got under the truck yesterday, and cleaned off the residual oil. Checked the oil pan bolts, felt like they were tight, but was able to turn an additional 1/8 turn on the
suspect bolts. Did not want to push my luck by trying to get 1/4 turn .
Also looked into the inspection plate for the aft engine seal, that looked nice and dry.
Will drive for a few days and monitor, keeping my fingers crossed.

 

[Hey you]

OK, time for an update. Good news, no more leakage after driving quite a bit. Still not 100% believing it... but looking good for now.
Decided to do the transmision flush, which although sounded easy... it was an ordeal. The principle of using the engine to pump out the
old fluid from the radiator connection and using an electric pump to put the new fluid into the tranny did work. But getting the tubes, containers
etc... took a while. Got the job done, and the hardest thing was the clips used to keep the feed pipe connected to the radiator.
So, for now I am keeping an eye on both the engine oil, and tranny fluids... no issues for now!

 

[swathdiver]

OK, time for an update. Good news, no more leakage after driving quite a bit. Still not 100% believing it... but looking good for now.
Decided to do the transmision flush, which although sounded easy... it was an ordeal. The principle of using the engine to pump out the
old fluid from the radiator connection and using an electric pump to put the new fluid into the tranny did work. But getting the tubes, containers
etc... took a while. Got the job done, and the hardest thing was the clips used to keep the feed pipe connected to the radiator.
So, for now I am keeping an eye on both the engine oil, and tranny fluids... no issues for now!

Lisle makes tools that allow you remove the pipes from the radiator fittings without removing the clips. Hayden makes a short brass pipe that we use to plug into the upper transmission return line to drain the fluid into a bucket.

Hayden 397
Lisle 22930

The oil cooler gasket is going to leak again, btdt.

 

[Hey you]

I did use the brass pipe for the drain process, worked great. Removing the clips from the radiator fitting was not too difficult... it was the reinstall that
cause me grief... that is until I found out that they should be installed without the pipe line installed, then simply push the pipe into the connection. After
it was secure, simply slide the locking washer over to keep it secure.
I notice my temps are averaging about 45 degrees above the ambient temp with the new fluid. Still much better than almost 200 before bypassing the
stock thermal valve.