My truck has a problem overheating when it is at idle for about 5 minutes. It is perfect while you are driving it, its just at idle. Im confused as all hell as to why.

Im running a 5.2 on the 3.9 Cooling system (rad etc)
-160 thermostat
-Clutch fan is put back on

The first thing that I put in it was the stock 195 t-stat but that didnt work for bologna.

I initially wanted to keep the clutch fan off of it, hence i bought the 160 t-stat. But at idle, I would get up to about 212 degrees(thats when my e-fan turns on)

I tried buying a 180 t-stat to see if maybe the 160 was stuck on an open-loop after awhile or something, but that was terrible. My temp climbed up to about 245-250 while driving.

So.... I put the 160 t-stat back in and installed my clutch fan back on as a last resort to fix the problem. No luck, Its acting just like it did when i was using the 160 w/o the clutch fan. At idle it gets up to about 210 degrees.

I did some looking and the 5.2 cooling capacity is only 0.3 quarts more than the 3.9 system, so it shouldnt need a bigger radiator or anything.

Help?

edit: I also notice tha when my truck is up to temp at low rpms my oil pressure drops to about 25psi. I know I have a bad rear main seal to replace since its leaking a fair amount of oil there. Could that be my problem here?

 

You might have air in the system. Need to burp it. Had the same problem, would only heat up when idling.

 

how do i do that?