Overheating towing with Denali 6.2L - Losing my F'n mind!!

Alright! Looks like a new radiator fixed the issue, fingers crossed! Install was fairly easy. I drove it hard up the pass and didn't budge over 210. I took some pictures and will attach them below.

Here's the new one, it is the one that is linked a few posts back. Seems to be pretty decent. Welds are good and it is a 3 core radiator with transmission and oil cooler hookups.



This picture shows the mounting brackets. They are a bit crooked and mounted too far out in my opinion. It made the install a little tough, I had to use a hammer over a cloth to get it to fit all the way in but it worked.


Next is a side by side of how much bigger the new one is compared to the old one. It fits nicely but the fan sticks out about an eight of an inch further than it should, its not really noticeable though. I also didn't notice anything wrong with my old radiator, no damage or anything like that.


Overall I think it was a good swap out for a budget option if you can't afford the Mishimoto.

puckhead said:

I guess so! I would have never known. I took it to a shop a few years back because the truck was going into limp mode, usually after towing. They suggested an auxiliary tranny cooler. It either fixed it or it has been a band-aid now for 3 years I think.

Click to expand...

From reading the shop manual, one of the issues with trans coolers and lines is that they get clogged up over time and reduce flow to the transmission causing them to get hot at the least. Make sure to the best of your ability that the lines and old coolers are flowing well; those that will be reused.

How's the Mrs and the new baby?

swathdiver said:

From reading the shop manual, one of the issues with trans coolers and lines is that they get clogged up over time and reduce flow to the transmission causing them to get hot at the least. Make sure to the best of your ability that the lines and old coolers are flowing well; those that will be reused.

How's the Mrs and the new baby?

Click to expand...

Wife and baby are doing great! Little bit of Jaundice but its all gone now.


Soooo....the radiator fixed the overheating and a new issue has popped up. I wonder if the overheating was masking this other issue.

Anyway, wife was driving and pulled into the driveway and it died like it was running out of fuel. Next day she drove it and threw the service traction control warning and code P0011. The print out from Autozone recommended replacing the variable valve timing actuator. Any other pieces of advise?

puckhead said:

Wife and baby are doing great! Little bit of Jaundice but its all gone now.

...code P0011. The print out from Autozone recommended replacing the variable valve timing actuator. Any other pieces of advise?

Click to expand...

That's good to hear! As for the Denali, code P0011 is for the Camshaft Position Actuator. Make sure the battery is fully charged, the oil level is good, oil pressure above minimum once warmed up and the oil clean and proper viscosity. Then you can command the actuator on with your Tech2.

Were you messing around the water pump during the radiator install? Check the CMP connector. The problem is either the ECM or the actuator with that code if its not the connection issues or oil and battery.

This thing keeps popping its head back! I drove it the other day and coming up the pass the temperature started to rise past 210. Didn't notice any performance issues and it did go back down after the climb. Still does just fine in the city and during long idling even while hot. Any ideas???

I changed the oil and cleared the code. I was a bit low on oil. We will see if P0011 comes back. No Tech2 yet, its on the wish list thought. Other than maybe some spilled coolant I didn't get close to the water pump.

I don't remember in watching this thread, have you checked head gaskets? I have never used one, but there is a "block tester" you can rent from auto parts store. I was going to check mine too since it has 274k on the odo. You have to buy the test fluid, and only use 1/10 of the fluid.

My 6.2 got a little hotter than normal driving up Sugarloaf mountain a few weeks ago, like the 225 range. I wonder if the lower plastic guard under the radiator has anything to do with it? I had to remove mine since it was broken in half, and that's when I noticed it got 10-20 degrees hotter than normal. Once I slowed down and the fans went to high, it cooled back down in a minute. I mention this plastic guard because I remember the 00's blazers with the 4.3 had that same shield and would overheat without it.

mikeyss said:

My 6.2 got a little hotter than normal driving up Sugarloaf mountain a few weeks ago, like the 225 range. I wonder if the lower plastic guard under the radiator has anything to do with it? I had to remove mine since it was broken in half, and that's when I noticed it got 10-20 degrees hotter than normal. Once I slowed down and the fans went to high, it cooled back down in a minute. I mention this plastic guard because I remember the 00's blazers with the 4.3 had that same shield and would overheat without it.

Click to expand...

It's a very good possibility.... the air damn under the front bumper is there for the same purpose.. it creates a low pressure area behind it which helps the air to flow through the radiator... that is why I am curious when I see guys trimming them down or removing them all together if they ever have any cooling issues.

Any update on the this? Is it still over heating?

puckhead said:

This thing keeps popping its head back! I drove it the other day and coming up the pass the temperature started to rise past 210. Didn't notice any performance issues and it did go back down after the climb. Still does just fine in the city and during long idling even while hot. Any ideas???

I changed the oil and cleared the code. I was a bit low on oil. We will see if P0011 comes back. No Tech2 yet, its on the wish list thought. Other than maybe some spilled coolant I didn't get close to the water pump.

Click to expand...

No, it has been all good. No issues! Might be a bandaid but it will work for us for a while.


Sent from my iPhone using Tapatalk