I've owned the rig since 2016 (it's a 2005 with about 165k on it), so going on 5 years using Wix filters and Mobil 1 during that time (as I have on all my cars since high school). The engine noise developed around 6 months ago and per my posts, was apparent at cold start ups with oil pressure also being low. Once the engine warmed up however, around 5 min or so, the noise went away and oil pressure would rise to normal.

I researched the heck out of what the problem could be and wasn't getting any where. I originally thought it was an exhaust leak. I did find a missing manifold bolt head and installed the repair kit, didn't fix the noise though. I knew my oil pressure was low and knew the noise was being caused by that low oil pressure. I also noticed that my dipstick had sort of a brownish oil varnish on it, perhaps evidence that something was sticky inside the engine. I had read about clogs that can potentially develop in lifters and decided it was at least worth a few bucks to do an engine flush as I have never done one before. I researched what I thought was the best engine flush product and came to Liqui Moly products of Germany. You can buy their Pro Line engine flush here:
I put it in, idled for 15 min as directed and was shocked by what came out. Anyhow, it fixed the problem, engine purrs like a kitten now.

I also tried the Liqui Moly fuel system cleaner and have seen a noticable pick in acceleration and power. Needless to say, I'm sold on their products

That's my story. Give their engine flush product a try and see how it works for you.

 

You also started a thread on having to add coolant to your truck on a regular basis, this tells a story of what could be causing the build up inside your engine.

Coolant will cause all oils to thicken and clog filters and passages within the engine.

Look for a internal leak of coolant


Neal