Truck is a 94 v6 5 spd. While I was fixing the oil leak by replacing seals on the oil cooler I noticed on top of the cooler, where the u shaped hose connects, the tube is full of some kind of tannish colored paste like material. Just wondering if anyone else has seen this and what it is.

 

Probably rust and crud from the cooling system, the hoses on the oil cooler send coolant through it to cool the oil. Sounds like a good time to do a coolant flush. How's the inside of the rad.

 

Well the radiator was only 3 years old but started leaking so i am replacing it right now since had to drain coolant anyway. Good thing for lifetime warranty. I think I figured it out. It looks like that leak stop crap from a few years ago. It had the rubber hose stopped up and the metal line so the coolant wasn't flowing through.