Engine overheating

[hugox_89]

Hi, I have a 2002 LTZ TB. As mentioned in the title... it is overheating when idling or driving slowly and with A/C on.
I have checked and changed all, radiator, water pump, thermostat, coolant, fan clutch, alternator, belt. I even added an auxiliary fan but that did not work.
I am being told I may need to resurface the cylinder heads. Could that be my problem?
Thanks in advance!

 

[TollKeeper]

When you changed the coolant, was is liquid, or were there chunky bits? or even thick liquid?

Almost sounds like an air pocket, or a clogged water jacket.

 

[hugox_89]

When you changed the coolant, was is liquid, or were there chunky bits? or even thick liquid?

Almost sounds like an air pocket, or a clogged water jacket.

Yes to both, thick liquid and some chunky bits. I will take a look at the lines and see if there is a clogged one. Will report back.

 

[Mooseman]

Sounds like the wrong coolant was mixed with the Dexcool or bad water was used, which causes what you saw. You will need to flush multiple times with water and a coolant flushing agent until it is clear. Then fill with Dexcool, either the premixed or a 50/50 mix of the concentrate and distilled water. Some city or well water also causes this.

This is a good video on how to flush the system.

I don't know how you checked the fan clutch but this is a good way to test it.
How to test the electro-viscous fan clutch
However, if the fan was roaring when it was overheating (it should have), then it's fine and likely not the cause of the overheating. Another sign that the fan clutch might be bad is poor A/C performance at idle.

 

[JayArr]

If you want to build a superflusher get a 5 gallon bucket and a submersible pump, the kind you drop into a pool to drain it. I bought one on Criagslist for $40.

Remove the upper rad hose or cut it in half and also remove the thermostat. Get some plumbing fittings and hose from the hardware store and rig up the submersible pump so that it pumps water from the five gallon bucket into the rad. Rig some hoses so that the engine sends coolant back into the bucket.

I put a bar on the bucket so the pump doesn't sit on the bottom, this allows sediment to settle. Fill the bucket and start the pump. The coolant will circulate through the engine. Now just keep changing the water in the bucket until it's clean. I had one Blazer where I had to change the water about 25 times. I would get a second bucket and just lift the pump out of the dirty bucket and put it in the clean bucket without turning it off, it would gurgle a bit and then re-prime and continue. Dump the dirty water into a toilet and fill it with clean water and repeat.

When the water starts to look cleaner then start the engine. Getting the engine hot will help flush out a whole lot more nasty stuff. When changing water buckets on a running engine I fill the fresh water from a laundry sink and I use hot water to start with so the engine doesn't get a shock of cold water.

In reality this will take a whole Saturday and some $$ but you'll end up with an engine block and cooling system that is really clean on the inside. It is 10X better than crawling under the car to remove the lower rad hose to drain the rad because you don't have to wait for the wtaer to cool down, you don't spill it all over the driveway.

 

[hugox_89]

If you want to build a superflusher get a 5 gallon bucket and a submersible pump, the kind you drop into a pool to drain it. I bought one on Criagslist for $40.

Remove the upper rad hose or cut it in half and also remove the thermostat. Get some plumbing fittings and hose from the hardware store and rig up the submersible pump so that it pumps water from the five gallon bucket into the rad. Rig some hoses so that the engine sends coolant back into the bucket.

I put a bar on the bucket so the pump doesn't sit on the bottom, this allows sediment to settle. Fill the bucket and start the pump. The coolant will circulate through the engine. Now just keep changing the water in the bucket until it's clean. I had one Blazer where I had to change the water about 25 times. I would get a second bucket and just lift the pump out of the dirty bucket and put it in the clean bucket without turning it off, it would gurgle a bit and then re-prime and continue. Dump the dirty water into a toilet and fill it with clean water and repeat.

When the water starts to look cleaner then start the engine. Getting the engine hot will help flush out a whole lot more nasty stuff. When changing water buckets on a running engine I fill the fresh water from a laundry sink and I use hot water to start with so the engine doesn't get a shock of cold water.

In reality this will take a whole Saturday and some $$ but you'll end up with an engine block and cooling system that is really clean on the inside. It is 10X better than crawling under the car to remove the lower rad hose to drain the rad because you don't have to wait for the wtaer to cool down, you don't spill it all over the driveway.

I have not had time to work on the flush. I was setting everything up to do it tomorrow. All I had in mind was buying a radiator flusher liquid and cycling a couple times. The procedure you describe is way better, thank you very much for the input. Will most definitely try this out. Thanks!!