its all good now. I posted to your new post. Oil cooler fixed it for me. I’m going to do an oil change soon too to get me back on schedule for the 5k intervals. So I’ll take another test and hopefully get a clean test. But all seems well now. No loss of coolant or gain in oil level. So seems like the fluids are playing nice again.

if you have coolant in your oil, the trans cooler replacement won’t help that issue. You’ll need the engine oil cooler. The trans cooler should be a relatively simple replacement. I don’t believe anything is mounted below it that needs to be removed. You’ll have to pinch off the coolant lines into the trans cooler though. That way you don’t have to drain and refill the entire cooling system, which you do need to do for the engine oil cooler, at least on the S8, I assume the 4.2 is similar in configuration.

oh, nevermind, I get what you were saying now. You did get the engine oil cooler, but thought the trans oil cooler was the one to replace at first glance. Nevermind. Yeah, might as well replace the serp belt and the pulleys while you’re there, but you don’t have to if the parts are still good. You’ll have more room to work than I did and can probably get the alternator out of the way without pulling the nose and radiator off. Just remember to loosen the alternator bolts a bit and tap them back in to loosen the inserts on the alternator mount. It will allow it to drop right out without prying at all.

just bite the bullet and pull the nose and the fans off, makes it much easier. And yes, you thread the bolts back in till almost tight and smack them with a hammer to push the threaded inserts back a small bit and it will allow the alternator to slide right out once you pull the bolts out. The threaded inserts bind on the back of the alternator and hold it in place after the bolts are out, so you will want to tap on the heads of the bolts to loosen them up a bit. I didn’t at first and struggled and pryed. But it wouldn’t come out, i was able to get the bolts out at first with fans in place, but then I pryed on the alternator and wedged it so bad I could not get it out or get the bolts back in to smack them. So I guess you can try to pull the bolts with the fan in place, but beware. And make sure you smack those bolts back before you try to remove them or you’ll be stuck. It’s so much easier with the fan and radiator out of the way.

I thought the manual calls for the radiator to come out too? But you will see once you give those bolts a whack, the alternator will almost fall out. Prying is unnecessary. I don’t know what you can get in there with to smack the bolts, but knowing what I know now, I’m sure there’s a way to hit those bolts back with the radiator in place, but it’s super right in there, and you won’t knwo if you’re successful until you go to pull out the bolts. Once the radiator was out, it was much simpler, and knowing now how to disconnect the hoses, it’s definitely the way to go. No more fighting.