Scope Cam found exact Oil Cooler Leak Location

[ron123]

The only way to see the exact point where the Oil Cooler is leaking was using Scope Cam with 45 degree viewer attachment.
It is likely the location where many others are noticing a leak around the cooler as well. Sometimes the dealer replaces gaskets or O-rings and then the owner reports the problem was not fixed. In that case it may be because the leak is actually occurring in the oil cooler "end cap that looks like a freeze plug" right near the top of the cooler adjacent to where the inlet/outlet fitting attaches to the oil pan. The location makes it appear like it is a gasket or oil pan leak. But using the scope with the angle fitting I was able to see it was really the end cap fitting (which is a pressed-in cap).

The following pictures show location.
First is a picture showing areas where oil drips are noticed. These are the most common points I've seen other threads report oil dripping - near blue arrows.



The next picture shows a blue arrow at the exact point where the end cap that looks like a freeze plug is pressed into the oil cooler. It is leaking at the margin of the end cap in one location. This picture is one I stole from the internet and shows a good view of the pan with oil cooler attached that has been removed from the engine. Blue arrow at top is where the leak occurs:



This next picture was taken off the screen of my scope cam using my camera phone - that is why pixels show up.
The shot shows the end cap margin where the oil leak/seepage is occurring.



Here is another view of the leaking end cap:


Before I took the pictures I cleaned up this area. Then let the car run for a few minutes and I could see the oil seepage was starting to flow out from the margin of the end cap again.

As mentioned, this end cap is completely hidden and can only be viewed with scope with angle attachment or by removing the oil cooler. It faces toward the back of the car toward the bell housing/block area and very little clearance at that spot. Notice that the end cap is almost at the same level as the pan gasket, and oil drips look like it is coming from the gasket or where the oil cooler attaches to the pan. But I checked all those locations and only sign of oil leak is right at the end cap on my car.

It looks like there may be some kind of sealer that is in the margin which the factory applies before pressing in the end-cap ... difficult to say if there is sealer or it is a dry fit. I'm guessing there are a huge number leaking at this same location. From what I see the only remedy is a new oil cooler or it needs an Oil Catch Can!!! There are actually two components to the assembly, the cooler itself which is double triangle shaped housing (rhombus) which bolts to the platform the oil and water lines flow through -- the combined assembly is fastened to the side of the oil pan with many bolts.

Here is a view of the cooler from another angle that I stole from internet, this shows the radiator coolant lines adjacent to the double-triangle Rhombus:


This oil leak started at 7,000 miles (or maybe day1 but that is when I first noticed), well within warranty. Good thing because the complete assembly costs hundreds of dollars.
For diagnosis of a mystery oil leak this is a prime location to check FIRST. My scope worked perfect since it has a built in LED light in the cam wand; it is fairly dark in this hidden area of the engine bay.
Wish the Chevy engineers would look at this, needs a redesign to come up with a better way to close off the end-cap to avoid leaks (maybe a threaded plug would be a good approach).
Ron

[sengli]

Great info, in case an oil leak starts in that area. Cudos for the great right up.

[Muscle Car Lover]

Wow, great work on this!

[Mean Green Z28]

Awesome find!