My truck is overheating after being still in the 100*+ temps here in Louisiana in 5:00 stop and go traffic. At nighttime, I haven't had a problem. I thought it was my electric fans, since one of my motors was broke for the second year. My truck was fine last year, even with only one motor and the a/c on.

One thing I have noticed though. My oil pressure guage drops to just under 40psi, like probably 38-39. Then my a/c starts warming up. I have to get up to 50+ mph for a few minutes for it to start going down. If I get stuck in traffic it goes back up. It seems like once it hits 210* it goes the big mark in between 210-260* really quick and seems to hang around there until I get back up to speed.

I've checked the coolant level, oil level and made sure the fans were on. What really stumps me is when the oil pressure drops.

Any ideas on what it can be? I'm gonna be pulling this 5.3 in the middle of October and putting in the 383. So, I really don't want to put too much money into fixing this problem. It has 96,xxx miles on it.

 

I recently had one of my 16" fans go out. Even with the 34" radiator, one 16" fan would not keep my h/c LS1 cool in stop and go with the ac on. Even with both fans going and the ac on, it will get up to low 200s while sitting. Once moving it will get in the low 190s-high 180s. Depending on what size radiator and fans you have, I can see it getting warm with only one fan and ac on.

 

i agree and you may be getting a small voltage drop if the battery is get old

 

i also concur. i have two 14" fans on the stock radiator. at idle my temps creep up. same goes for stop and go. once moving my temps drop back down. i think it's just this summer. i have a few local people to me that are having the same issues with their trucks. some even have clutch fans.

as far as the oil pressure, i don't know.

 

I'm having that issue myself. I have two 12" fans (I know, they're small), and 12V of power kept the highway temps (cruise @ 70mph) at 205* all this week. Once I hit the Stop & Go areas of Baton Rouge, temps creep up to 230* (HPT reports near 250*). They creep back down to 217* once I'm moving.

Like goshawk said, I think it's more related to summer temps. It was 101* in BR on Wednesday afternoon. I'm changing my oil this weekend (first oil change since motor swap), and I'll add oil treatment additives. Hopefully, that'll up my oil pressure from 50 to normal range of 60 - 65 (@ cruising speeds of 70mph). Right now, my truck idles with oil pressure just a hair below 25. Not really sure about any relation b/t that and temps, but there could be.