This sure did surprise me. Hmmm, I think I will start where the antifreeze and any oil exchange heat. Could be transmission oil or engine oil on a Purring Cat 3208. Any member that would like to suggest on where to start, I am open for suggestions.

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I was thinking of adjusting valves also. I don't know if
there are not many Caterpillar owners on here that will do valve adjustment themselves, besides me. After talking to Tom Johns, I would rather trust myself.

Hmmm. I don't know the internal layout of the Cat 3208 motor. Maybe some Cat user forum would have experience.

Since the 3208 is not a wet/sleeved engine, we can eliminate leakage there as the problem area.

Next guess would be the oil cooler, trans cooler, maybe intercooler, or head gasket...

Not sure what "oil sheen" means... One drop of oil can make a sheen on an entire swimming pool. Is it possible your sample was contaminated? Do you have any cooling additives that might spook the test? Interesting

Valve adjustment ain't no big deal, long as you have a barring tool to turn the engine over.

https://www.wanderlodgeownersg...rumdisplay.php?f=127

Very good information regarding the 3208

Check the engine oil - any milkiness is an indicator.

Thanks Rusty, I intend to have the oil tested also. Marvin called and we talked about the Wander Lodge link for the caterpillar 3208. I did not expect such a fast response. I will not be working on the Barth till after Thanksgiving. It is nice to have more than one mind thinking about this problem.

https://www.blackstone-labs.co...qmshtbkijbe%29%29%2F

never used them myself but know others that did

I've had several aviation oil analysis done by Blackstone Labs. Good company, no complaints.

Gas engine would be bad head gasket at best. Don't know diesels.

Hey Kevin, I read an article last night that said if coolant is in the oil, you have a bad head gasket or cracked head, but if there is oil in the antifreeze, you have a faulty oil cooler. It would be worth checking out.
Later
Kenny J

My guess is that either the trans cooler or engine oil cooler is leaking.
If anti freeze gets into the Allison your looking at a trans rebuild.
I would replace both coolers. They are due anyhow. And the least expensive choices.

As soon as my Barth gets into its warm garage, I will be looking at all the suggestions, starting of course with the transmission cooler. Marvin called me within an hour of my post to alert me of the potential problem this could lead to.

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Thanks to all the suggestions. If there are more thoughts please post them here or give me a call. With our 4000 plus members I am sure I can get the problem solved.