Cat 3406e getting hot

It is when fan cant keep up I get worried. Btw, you don't have one of those cool looking nylon mesh bug screens do you? The kind with flames or teeth or big logo? Caused me headaches with my W9 years ago. Locked fan would barely prevent overheat with empty bullrack in cross wind...

 

Never had a water pump impeller slip myself, but it does happen. Use to be a write up on here or DG by Johnp3 on testing for that. And finally my last bit of knowledge on this subject and then I will shut up. I bought my W9 in 96 . It was 3yrs old. By the time it was about 6yrs old I had replaced water pump, had radiator removed and rodded, Rebuilt timing advance and other vain attempts at getting it to cool properly in even mild temps. Just drove with fan locked all the time if it was over 75 out. Finally took radiator out again because I got suspicious of the shop that charged me for pulling it and having it rodded. Took to radiator shop and the old man that owned it looked at in in bCk of my pickup. He took out his pocket knife and stuck it in the fins in several places. He says "here is your problem son" as he moved the fins up and down on the tubes like an accordion "fins are detached from tubes- lack of heat transfer" I already had tank off of top and that part looked fine. This was on a 5 or 6 yr old radiator that didnt really show much exterior corrosion. Replace core. Problem solved. Just thought I would pass on what little I have learned over the years. I am the old man now...