I'll clean the raditor inside and out before I do any towing. I had no issues until I added the turbo also no power!

What he said. Inside AND out cleanliness is paramount. These babies generate a lot of coolant heat and need to get rid of it....... I think a 6.5 idling puts out as much heat as a lightly loaded cummins cruising down the highway. LOL

I would not run a flush in a aluminum radiator. The core tube thickness on one is .010 of a inch and running acid through it is just asking for a leak. Clean the out side of it with a pressure washer and if your problem doesn't go away then you need to replace it. After about 10 years of use they build a scale in them that limits there ability to transfer heat. If you replace it run the premixed anti freeze or distilled water. Any acid in the water can chew through them in no time.

Most engines build more heat idling than going down the highway due to the lack of air flow.

My Overheating Problem Solved
 

I went with the Heath Diesel waterpump kit. I replaced the AC condenser, had the radiator serviced. When I installed the pump I found the real issue, I had a early model water pump that was rotating in the wrong direction. I'm suprized I did no damage to the motor. At the time of my turbo install I replaced the water pump with one I had from a old motor. I had to press the V belt pulley off and replace with the serpentine belt pulley. Bill Heath couldn't believe it when I called and talked about this story. I did all this in July and had no issues when towing what so ever in the summer heat.

Did you end up buying the kit? Im looking into it as well

The HO water pump will fit on a 92-93. I have one on my 93 with the double thermostat cross over. I know there is alot of controvesy out there reguarding running both, but my temp guage never moves. I can tow a load, or just run the truck, and it sits still once it is up to temp......:c:

Here's the thing;

gm installed the dual thermostats in order to flow enough gpm to keep up with the higher flow pump that started in (I think) 96.

Up to that point, the single had enough surface area to flow what the pump would put out.

Now, single or dual?

I run the dual for a couple reasons.

1. It came with the truck (no money spent)
2. it keeps up with the flow of the higher capacity pump
3. it doesn't block off the bypass.

That last one is where most of the contention about "what is better" lies. Some think recirculating some coolant is bad and would prefer it all be forced through the rad before returning to the block. The single thermostat does this at full open.

The dual does not block the bypass. I prefer this for reasons I won't go into here.

To each their own.

Last time I talked to Bill, he wouldn't bother swapping out a dual for a single is the truck already had one. He does recommend a restrictor for the bypass in the dual when using one of his pumps though.

Balance flow and all that kind of jazz....google will turn up lots of "controversy" on the subject so I'm not going to go into it. I have no taste for that sort of thing anymore.

:s: