Well, I may have found a problem with my oil cooler. My cooler bundle appears to be have been either manufactured poorly or damaged by a previous repair job. On one end the inner land that stops the large green o-ring is wavy. It seems to be bent towards the end between two of the four spot welds holding the land to the cooler body (on the rear header side). Measuring the ID between the the inner and the outer land, I have a runout of 0.050 inches. It looks to me like someone might have banged on the land (why?) and pushed it in by the 0.050 amount. This would result in uneven pressure of the green o-ring against the land. I don't know if this is a big deal or not. Maybe the flexible o-ring just squeezes a little tighter here and there is no concern. Could I just take a torch and heat the ring as best I can and try to tap it back the other direction to make it more parallel with the other one? Has anyone ever seen this before? I got the shop manual and took the cooler apart (it was easy) per the instructions. The wavy section was on the rear header. When I took the cooler apart the rings looked good. All four were intact and soft. The cooler bundle looks to be new, there wasn't any junk blocking any of the water tubes. I'm thinking my oil in water symptom is not related to this, I don't think those header bolts were tight enough into the block and the rear header gasket looks like it might have been leaking across the oil side to the water side. I am pretty sure a previous owner may have had this repaired, and maybe the gasket to block on the rear header failed. The oil cooler did not leak oil externally, at either end.
Thanks, Sam
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