Coolant temp rising during idle, AC blowing hot during idle.

[AN292]

Let me start off by telling you what has been replaced on this truck, everything below is essentially brand new/less than a year old and OEM/ACDelco

• Water pump (2 weeks old)
• Coolant
• Fan clutch
• AC blend door
• I have a new thermostat that I need to install as well.

So when I idle, my coolant temps go up from 210 to about 230. Also when idling, my AC will go from freezing to hot, and I can hear/feel a jolt or something engaging/disengaging. Along with this I will get a fluctuation in how aggressive the air is coming out of the vents. Sometimes its blasting and sometimes you can hear and feel it weaken. I can confirm my blower motor is very clean, although it could be a bad unit.

Temps go down and AC gets cold when I start driving. Occasionally the coolant temp will go very slightly above 210 during a drive but nothing that would make me worry. Also during drives my coolant temp will actually dip below 210 and go into the 185-190 mark.

I had a water pump leak that was fixed with the installation of the new pump and my coolant levels are on point.

Some things to consider as well: My cooling fan has never been replaced and the bottom fan shroud is missing.

Im all out of ideas, thanks for any help.

 

[Fless]

Seems to be all about air flow, and the fan needs the lower shroud to help it pull air through the radiator at idle. If you don't have the lower shroud it shouldn't be too hard to find one at UPull or a junkyard. And get that thermostat replaced; hopefully you're using one that's OE temp.

If that doesn't help significantly, then I'd suspect that the radiator is partially clogged. Might be time for a new one.

 

[Scottydoggs]

sounds like the fans are not coming on. when the ac is turned on, both fans should be on. regardless of coolant temp.

edit, missed the whole clutch fan part. try spraying the rad and ac condenser down with de greaser, hose it out. the rad's get clogged up with dirt and bugs and the air dont pull through so easy with just a clutch fan.

 

[AN292]

Interesting guys, when I was having this leak I did use stop leak twice. Maybe **** clogging stuff up?

I will double check the rad fans and make sure they are spinning. Thanks a ton

 

[Fless]

One fan, since it's a fan clutch. The fan should have a little resistance, but not a lot, when the engine is cold. When the engine is warmed up you should have a difficult time trying to spin the fan. Both tests with the engine off....

 

[AN292]

One fan, since it's a fan clutch. The fan should have a little resistance, but not a lot, when the engine is cold. When the engine is warmed up you should have a difficult time trying to spin the fan. Both tests with the engine off....

Yeah just did this test, I had slight resistance cold, little more after a drive

 

[BG1988]

sounds like the fans are not coming on. when the ac is turned on, both fans should be on. regardless of coolant temp.

edit, missed the whole clutch fan part. try spraying the rad and ac condenser down with de greaser, hose it out. the rad's get clogged up with dirt and bugs and the air dont pull through so easy with just a clutch fan.

Yeah it makes a HUGE difference 8-10 degrees cooler for the A/C when i did that last year..

 

[exp500]

You really need that fan shroud. as you have now noticed. U pullit or car-part.com.

 

[ROGELIO A GUZMAN]

I had all the same issues. I replaced the same thing you did. I eventually replaced the radiator. I guess the previous owner had put a china replacement rad. I bought an OEM and all my overheating issues were fixed.