Over-heating Alpha when towing. Need some advice.

[Hans3T]

Hey H4O / Tustin,

I've been on the road from VT to VA all day today and the T has hit the red "H" zone on the temp gauge 4 or 5 times today, and is running hot in general. I am towing a 4x8' U-haul and have the slantback loaded with boxes, but I believe that I am still well under the maximum towing capacity.

The over-heating alarm and message came on during long, slow hill climbs in the mountains of NY and PA, forcing me to drop to around 40 mph and blasting the heater until the engine cooled. Checked the coolant level and it is where it should be. The rest of the drive on level/slightly hilly road my temp gauge was spiking between 1/8th cool and 7/8ths hot. The outdoor temp was between 60 and 75 degrees the whole trip, so nothing crazy there.

Anywho, I have a 6am appointment at a GM dealer here in Winchester for diagnosis. My old man thinks a stuck thermometer and my brain thinks end of the world. Or, could it just be that I'm over-heating because I'm towing and this is normal? Tomorrow I have to drive the T from Northern VA to southern NC (~500 miles) so I'm freaking out a bit...

Not sure if anyone will see this tonight, but I figured I'd give it a try.

 

[3Hummers]

Thermostat is a good guess. Have you had the cooling system flushed? The Alpha tends to run hot as you know but I have not had an overheating issue like you describe.

 

[Hans3T]

I have not had it flushed. I've only got 25k on the odometer and the owner's manual says its good for 5 years/150k miles... I was going to add water but the manual said that is a no-no, so I didn't do that.

:sigh:

 

[06 H3]

damn! I run my 06 which runs hot with a small 6x10 trailer with a buggy and dirtbikes on it up the grapevine (steep steady grade) in 90+ degrees and never hit the redzone.

Sent from my DROIDX using Tapatalk

 

[H3slate]

Mine did the same thing, and it was the thermostat. Definitely get it fixed before finishing the drive.

 

[Portager]

My best guess is the thermostat.

Unless you have blockage of the airflow into the radiator. Like offroad lights?

Another thing that could cause overheating is mud clogging airflow through the radiator.

 

[Hans3T]

Mine did the same thing, and it was the thermostat. Definitely get it fixed before finishing the drive.

Good to hear I'm not alone. Thank you! :hans:

My best guess is the thermostat.

Unless you have blockage of the airflow into the radiator. Like offroad lights?

Another thing that could cause overheating is mud clogging airflow through the radiator.

No off-road lights...I do have the BA bumper, but I doubt that is causing the problem. I've had it one there for over a year with no problems...I've even does this same drive a few times.

Debris in the radiator is a possibility. I always do my best to gently clean it out after hitting the trails. Haven't been in that situation in over 6 months, and, have done this same drive with no problems.

The "X factor" in this equation is the U-haul... I'll keep you gentlemen posted.

 

[RuggedH2]

Yep. Something is wrong. I hope it turns out to be simple, like the thermostat.

I pulled two Harleys to Sturgis (around 800 miles) with the engine cranking out high RPMs (especially while climbing), in a loaded cargo trailer with gear and supplies for two weeks (tents, bedding, clothes, tools, etc.) in the little 5 cylinder, in August... and my engine never even got close to overheating.

IMO, that Alpha should be able to pull that load easily.

 

[bro of bro of 3 & 3hummer]

Check the radiator cap.

 

[SolidusJ]

As you know I just made a 1,3XX mile pull with 5,000+ LBS (10,620 LBS with everything all together) with the 3.7L and my max temp the whole way with 212 with and avg 204 the PCM fan was a big help. Like everyone said good chance it's your stuck thermostat you'll be good as new when you pop in the new one.

 

[alrock]

I think we found the answer - you need to get rid of that V8 and go with the I5. Done!

 

[Portager]

Double check your tire pressure, especially on the trailer. Also check the tongue load. It should be between 10% and 15% of the trailer weight. Closer to 10% is preferred unless it starts wobbeling.

 

[SC_Hummer_Guy]

I think we found the answer - you need to get rid of that V8 and go with the I5. Done!

Haha isn't that rather reverse of the norm around here Alex?

And Hans, I had that problem a good bit back and it was the thermostat. And that was just from pulling a uhaul like your doing.

 

[hummech]

i would have the dealership check thermostat but i would also have then inspect the trans for overheating. if this only happens when you tow, i have found that the trans is running hot, the cooler is up at the radiator which with a 240 degree temp around the radiator won't remove the heat from the engine. have the dealer look for trans over heating codes while they are at it just in case. most likey the thermostat but worth the look while you are there.
let us know what they find,
mike s.

 

[twinmill28]

I like what hummech says.
When we pulled the trailer up the mountains and across the desert, I could watch the trans temp climb and take the engine temp with it.
I knew the solution was to put a trans cooler on it but since we left the mountains and don't drive across the desert any more, it's not an issue! I only pull the trailer in short bursts on flat land now and life is much better for the deuce.
Also, not sure if you're running a tune, but that really wreaked havoc with the temperatures while pulling a trailer as well. I went back to the stock tune with Super Unleaded and it tows like a champ now---given that I drive within the deuces limits and don't try driving it into the ground.

 

[LagunaH1]

Yup, the alphas run hot but not this hot. Looking forward to hear what you find out. Good luck dude.

 

[Hunner]

I have an H3 Alpha if that was what we are talking about. I just towed my Whaler from Arkansas to Perdido Key Fla. in 90-100 degree temps and mine with a Warn Power Plant stuck up in the front and an air tank under that behind the bumper but the cooler is below that. It ran 190-212 degrees at about 65 mph speed. If I got in stop and go traffic it hit 220 a couple of times but came right back down when I started moving. I also had my cargo carrier mounted on top for more drag.
That was with the AC on, of course.
I have a Flashpaq set to tow mode.

What's normal?

 

[Hans3T]

i would have the dealership check thermostat but i would also have then inspect the trans for overheating. if this only happens when you tow, i have found that the trans is running hot, the cooler is up at the radiator which with a 240 degree temp around the radiator won't remove the heat from the engine. have the dealer look for trans over heating codes while they are at it just in case. most likey the thermostat but worth the look while you are there.
let us know what they find,
mike s.

Wish this post was earlier, but with a coastal time difference I can't complain.

Dealer had it for 3 hrs running "tests" and found nothing. Trans and engine fan are operable, coolant is good, thermostat was not stuck... So my truck got a clean bill of health from them.

Could this be right?

>Sent using Tapacrack<

 

[LagunaH1]

How much weight are you towing and how much is the truck carrying?

 

[3Hummers]

I hate that " we couldn't duplicate the problem" response. While I know it is legit in many cases it is frustrating. How is the truck running today?

 

[LagunaH1]

How fast were you going up those inclines before dropping down to 40?

 

[Sierra H3]

You may want to search for a mechanic that is more of an Ace on coolant systems. Parts don't always fail hard, sometimes they hold up during "testing". If it was my truck, I might swap the thermostat anyway just to rule that out. FYI, elevation makes a big difference in towing capacity.

 

[Hans3T]

How much weight are you towing and how much is the truck carrying?

My guess is 3k lbs total. Nowhere near the max rating.

I hate that " we couldn't duplicate the problem" response. While I know it is legit in many cases it is frustrating. How is the truck running today?

Much of the same, but I kept it out of the warning beeps by easing down before it got as bad as yesterday again. My old man called GM and opened a case for me while I was driving. There's a Hummer dealer in Wilmington I'll take it to sooner than later.
Good news is I made it to my final destination.

>Sent using Tapacrack<

 

[Hans3T]

How fast were you going up those inclines before dropping down to 40?

No faster than 65 on the flat driving all day. Cruised at 55 mostly. On hill declines hit maybe 70 for brief stints.

>Sent using Tapacrack

 

[Hans3T]

It ran just about this hot for the whole 500 miles today.

>Sent using Tapacrack<