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

[puckhead]

**Update**

Alright, I wrapped my fuel lines and rails in the engine bay. Didn't do the ones under the truck next to the transmission.

Drove it today in 95-100 degree temps in the city then up a mild mountain pass. Here is what happened.

Denali did good all day in the city with the A/C on the whole time. Started heading up the hill and the temp spiked to about 200. Turned the A/C off and pulled off to the side of the road and it cooled down real quick. Even turned the A/C back on. Hooked up my OBDII reader for some more accurate reads.

Started up the hill again with A/C on and got the Service Stabiltrac/Traction Control Off messaged. Didn't notice any performance issues so I kept going and the warning light eventually went away (10 minutes maybe). During this time my temps went up to 232 degrees but it never died the rest of the trip. It cooled down for a while then spiked to 225 as we were getting home.

Don't really know what to think of these results. Is it normal/safe for the temp to get up that high? I was unloaded and not towing. Just me and the A/C.

Edit to add. Wife always fills up with 91 octane, so do I. I also dumped in a bottle of Sea Foam for good measure.

 

[gpracer1]

Not towing and that high of trans temps I wonder if the converter is not locking up.

 

[swathdiver]

During this time my temps went up...

Have you pressure tested the radiator and made sure both fans are functioning at full power?

 

[puckhead]

Have you pressure tested the radiator and made sure both fans are functioning at full power?

I thought the shop I took it to did the pressure test but that was just for the fuel pressure. How do I go about doing a pressure test? Is there a gauge I can buy for the coolant reservoir?

The fans seem good. I have seen both at a low and a high setting.

@gpracer1 These are engine temps, not tans temps. Trans is good.

 

[swathdiver]

How do I go about doing a pressure test? Is there a gauge I can buy for the coolant reservoir?

Exactly! Craftsman, Harbor Freight, Amazon, local auto parts store or maybe even a neighbor with a race car down the block.

 

[puckhead]

I will check that, thanks! This thing is killing me!

 

[kbuskill]

I will check that, thanks! This thing is killing me!

To me these are positive results.

To keep me from going back and rereading 6 pages... Did the stalling problem happen before without pulling a trailer???

 

[puckhead]

To me these are positive results.

To keep me from going back and rereading 6 pages... Did the stalling problem happen before without pulling a trailer???

Yes it did. I would say its a hair positive. I think the heat tape helped a bit.

 

[gpracer1]

I thought the shop I took it to did the pressure test but that was just for the fuel pressure. How do I go about doing a pressure test? Is there a gauge I can buy for the coolant reservoir?

The fans seem good. I have seen both at a low and a high setting.

@gpracer1 These are engine temps, not tans temps. Trans is good.

Sorry I thought I saw trans temp

 

[intheburbs]

**Update**

<snip>

During this time my temps went up to 232 degrees but it never died the rest of the trip. It cooled down for a while then spiked to 225 as we were getting home.

Don't really know what to think of these results. Is it normal/safe for the temp to get up that high? I was unloaded and not towing. Just me and the A/C.

Edit to add. Wife always fills up with 91 octane, so do I. I also dumped in a bottle of Sea Foam for good measure.

Both of my trucks stay dead-nuts at 210° 100% of the time. The needle never moves. Only time they go higher is when I'm towing, and only then when I'm really working the engine.