Does anyone ever look down the oil tube to see how clean the oil is keeping the right cylinder head. I have a varnish build up on mine that wasn't there before I put on a set of Troyer e-fans. Truck never overheated, but there is a big temperature diff. at the radiator with and without the e-fans (like 80 degrees from where the probs were, I returned it to stock). I followed the instructions by the book and I think it fried the oil on the head (synthetic oil at that). Anyone had anything like this happen and any tips for a good internal cleaning?

Did have a tech look at the engine temp with a scan tool and it always stayed around 198-200 F.

'02 Screw 5.4, airforce one, magnaflow SISO, hypertech, and recently departed e-fans

 

I think your varnish buildup that wasn't there before and there now.. is not from the fans... but from more miles than before. and maybe synthetic isn't all you thought? The varnish could be from the oil cooling quickly at the top of the head.