Temp 3/4 way high, fan growling

[treehan77]

Noticed my temp was way higher than normal, and the fan was super loud when I pulled in to work this morning. Curiously, when doing 65-70, temp indicated hotter than when I parked and idled, it went down. I’d expect the opposite. Haven’t had time to look at it yet...

 

[SnowDrifter]

Efans or mechanical?

Coolant level?

Any other pertainant info - things you've checked, your own mechanical ability, etc

 

[treehan77]

It’s an 05 so E-fans. Haven’t had time to look at it, it was in way to work. Just wondering g if anybody could explain why crusading would cause higher temperatures than idling at park. I thought wind going through the radiator would cool it instead...

 

[iamdub]

It’s an 05 so E-fans. Haven’t had time to look at it, it was in way to work. Just wondering g if anybody could explain why crusading would cause higher temperatures than idling at park. I thought wind going through the radiator would cool it instead...

The cooling capacity isn't sufficient for the load when cruising, and it's (apparently) not due to insufficient airflow. Either the engine is making more heat than normal at those load levels (not likely) or the coolant isn't transferring the heat to the radiator as efficiently (more likely).

Perhaps you're low on coolant? Air doesn't conduct heat very well.

Maybe the coolant isn't flowing like it should? Thermostats can get stuck partially open or closed and water pump impeller vanes have been known to erode. When idling, an engine is producing less heat so an ailing cooling system may still be adequate. If the coolant is low or if the impeller is worn, the water pump may still be able to pump the water sufficiently at lower engine speeds, but it just cavitates the water at higher engine speeds.

 

[mattbta]

I've got a slow leak on my water pump. Have to top it off every couple of weeks. If I forget and in the Texas summer heat, if the level is low (but not low enough to trip the sensor) it will start trying to creep up on me when moving but idling it goes back down. Check your coolant level when cold.

 

[Chris2144]

Pretty safe bet it has nothing to do with the fans. The louder than normal is because temp is higher than normal and both fans are on high at that point. Coolant level needs to be checked. If good than I would check radiator temp vs engine block temp this will tell if the thermostat is sticking and verify the sensor is correct

 

[treehan77]

It was low, had no choice but to put in maybe a gallon of water from the gas station. It didn’t get over normal on trip home. Probably a small leak, Ive been driving it a lot this last month (usually only drive it on weekends). My wild guess is water pump is dripping and burning off. Can’t get to look at it till Thursday

 

[OR VietVet]

Look for your leak but if you have access to a digital infrared thermometer I would start looking for cooler spots on your radiator that is indicating poor flow. Replace the thermostat because it got hot as well. A radiator that has even flow will show close to the same temps all over the surface. You may have to get one that has a probe.

 

[Chris2144]

You will be able to tell pretty quick if the pump is leaking whatever color antifreeze you have there will be a substance that same color dried up on the block. If it has dexcool in it now is the time to ditch it. Make sure you do a complete flush and run cleaner through it I use zerex coolant. It's a little pricey but imo it is the best you can get. Can be picked up at the local part stores. As has already been said make sure the t stat is replaced. Also check the plastic quick couolers for the heater core at this age they like to get weak and break.

 

[treehan77]

Replaced both plastic T fittings 6 months ago. Thought I had fixed the leak...

 

[treehan77]

Spent 2 mi it’s on the ramps and it made a good size puddle right away. I guess I’m glad it’s coming out onto the ground as opposed to “disappearing” into the motor. Is water pump the consensus? Couldn’t see it coming out anywhere while it was running, but it’s covered with dexcool everywhere.

 

[treehan77]

 

[BG1988]

thermostat not opening all the way, can cause it to run at 3/4 temp ..

 

[OR VietVet]

Drips on the linkage looks like water pump leak and I would never ever change a water pump without doing the thermostat at the same time.

 

[iamdub]

Drips on the linkage looks like water pump leak and I would never ever change a water pump without doing the thermostat at the same time.

Easy job. Check the coolant crossover hoses under the throttle body, too.

 

[Chris2144]

Agreed can be done in an afternoon. Flush it clean it new pump and thermostat bleed it and you're good to go

 

[treehan77]

Easy job. Check the coolant crossover hoses under the throttle body, too.

Does on 05 have this still?

 

[treehan77]

Ok, for a 2005 Yukon 4.8, can anyone tell me which of these I Need-
ACDELCO 252845 or 251743?

anything else? Do I need a new housing or something?

 

[OR VietVet]

I would use the 251743 Water Pump-AC Delco, 131156 Thermostat-AC Delco and the 35720 seal by Fel-Pro.

The AC Delco parts are OE equivalent and I love Fel Pro quality.

All available at Rock Auto

Because I am so OCD I would also run a nice clean tap in the mounting threaded holes to clean them out before reinstalling the mounting bolts.

I don't see that the water pump comes with the gasket/seal. Seal-Fel Pro #35633

Gasket-Fel Pro #35635 or AC Delco #251663

 

[treehan77]

So I don t need a new thermostat Housing?
https://www.rockauto.com/en/parts/acdelco,1511057,thermostat,2200