Hey guys I recently swapped my 4.8 to a 5.3 and the engine is overheating but is not overheating all the way thru it stays in the middle of 210 and 260 I replaced the radiator and thermostat and I’m still having the same issue I’m currently running one electric fan out of the 2 cuz I cut the live wire and burned the fuse of one fan but the thing is that while the truck is at idle or at a red light it stays below 210 but once I’m cruising or in the freeway that’s when it stays in the middle of 210 and 260 so technically at 240F really don’t know why is doing that I need some answers plz

 

are going by the gauge on the dash or an actual temp sensor? Check your temp sensor on the head, make sure there arent any cracks in it. Maybe the system needs to "burp" an air bubble, or your water pump is on its way out.

 

Im going by the temp on the dash and do I check the temp sensor for cracks or the actual head of the engine, im also considering that my water pump is going bad as well and how do I make the system “burp”

 

What year is the truck?

You could have an Air bubble in the cooling system or the E-Fans are not set up correctly.

You definitely need to fix the issue you did describe with the Efans.

 

The truck is a 2005 but the engine is from a 2002 truck and I’m trynna get the Efans fixed today
How do I check for air bubbles in the system?

 

Lisle makes a funnel with a bunch of adapters to thread onto radiator or overflow tank. I bought one of them, but never had a need to use it on these engines.

Things to check: dunk thermostat into an old pot of boiling water and check that it does open.

Hook up a scan tool with live data to ensure guage and what ECU is seeing are the same.

Was the 5.3 a good running engine?

 

They told me the engine was running good but the transmission went bad on it I didn’t get too much information

 

I get the nose up as high as possible with jack stands and then leave the radiator cap off and let the truck run for 30-45mins.

 

I had the exact same symptoms when one of my electric fans quit working. Fixed the fan, fixed the problem.

 

Fixed the problem guys I had air bubbles in the cooling system thanks for the help