so today was hot...

[MarK M]

and i noticed when driving the 3 today that my temperature was up to almost red.

I managed to bring it down by turning off the A/C. I first notice this happen when we went to our Death Valley trip.

I couldn?t imagine it happening to me now. For the folks that know Northern California, we have Altamont Pass, which is a climb but not too steep. The Grape Vine going to LA is worse. Anyways, this is where i noticed my temperature soaring high.

Is there anything I can do to eliminate this? Adding a bigger fan? Changing the thermostat so that it kicks in the fan sooner? I was even thinking as far as adding a sprayer for the radiator to help with bring the temps down. Kinda like the evos had on their first year production for the intercoolers.

thanks,

[RIC-H0]

Originally Posted by MarK M

and i noticed when driving the 3 today that my temperature was up to almost red.

I managed to bring it down by turning off the A/C. I first notice this happen when we went to our Death Valley trip.

I'd check your tranny temp before I did anything else. Check the trans. fluid and see if it's still red or a dark burnt color. If it's dark, I would definetly take it in for the trans overheating, thus causing everything else to run hot.
IMO

[evldave]

How many miles do you have? I'm starting to see more people make comments about cooling issues (and it's getting close to summer). Not a lot yet, but it's starting to warm up here, I've got 11k miles on my rig, and the 'stabilized' temperature I'm seeing is noticeably higher in the warmer weather with more miles on my rig. It's supposed to be 100 here in a few days, guess we'll see.

[Michael1]

Originally Posted by MarK M

Is there anything I can do to eliminate this? Adding a bigger fan? Changing the thermostat so that it kicks in the fan sooner? I was even thinking as far as adding a sprayer for the radiator to help with bring the temps down. Kinda like the evos had on their first year production for the intercoolers.

thanks,

I wouldn't do any of this. I would complain to the dealer. Something is not right here, and may not be right with an entire block of production. It could be the fan clutch, the radiators, fan pitch, etc. The H3s should not be getting this hot. You're not even towing a trailer! GM has higher standards than this, so either engineering screwed up, or the supplier is providing parts which are out of spec. You should be able to tow a fully laden trailer (3500 lbs with manual, 4500 lbs. with auto), up a grade (such as the eastbound 15 Baker grade in California) at 100F with the A/C on full at the speed limit (or as fast as the truck will go). If it can't do that, there is something wrong.

Michael

[evldave]

hmmm, maybe I should turn off my DRLs, thereby reducing the load on the engine and possibly lowering the likelihood of overheating.

WAIT! The DRLs are causing the overheating. Can you imagine the amount of extra heat produced by all these cars using DRLs? It's not greenhouse gases causing global warming, it's Daytime Running Lights! OHMYGOD! We need to put a stop to these DRLs now, before we pass along a legacy of wanton waste to the next generation of car buyers

Screw the DRL's, I don't want them on usually. But it's not going to solve the overheating problem or save me a thimble of gasoline.

Never experienced much temp gauge movement past midpoint with my H3 even on Altamont pass. Mark - something's wrong I think.

S.

[f5fstop]

Originally Posted by Michael1

I wouldn't do any of this. I would complain to the dealer. Something is not right here, and may not be right with an entire block of production. It could be the fan clutch, the radiators, fan pitch, etc. The H3s should not be getting this hot. You're not even towing a trailer! GM has higher standards than this, so either engineering screwed up, or the supplier is providing parts which are out of spec. You should be able to tow a fully laden trailer (3500 lbs with manual, 4500 lbs. with auto), up a grade (such as the eastbound 15 Baker grade in California) at 100F with the A/C on full at the speed limit (or as fast as the truck will go). If it can't do that, there is something wrong.

Michael

Agree take it to the dealer. If the coolant is that hot, you don't want to mess around, especially with an aluminum block/head engine. But let's add in the fact it might not be the coolant overheating, it might be a sensor is bad and giving a bad signal to the PCM. A tech with the Tech 2 can determine this in minutes.

Other point, if you are driving at speeds above 30-40 mph, no fan in the world can draw any more airflow through the radiator, than what is being pushed in by the movement of the vehicle.

Do you have any restrictions in front of the radiator?

As I told someone on another thread, if the sensor is ok, have the dealer to a drain and then a Vac-and-fill of the coolant system. If there is a possible air bubble in the engine, it can cause overheating, and this has been a problem with some of the Ecotec 4-cylinder engines. Haven't heard of any problem with the Vortec inline engines, but who knows. The vac-and-fill method prevents any air bubbles from forming inside the block. Just some ideas from my easy chair

[MarK M]

Thanks guys for all the comments. I'll definitely take it in to the dealer for them to look at.

As far as restrictions, I really don?t have any except for the warn box where I connect my controller. I can?t imagine this would cause this as the box is small; plus I didn?t have this box when I was in Death Valley.

[MarK M]

one more thing... I've wheeled several times since i got the 3. Should I have them do a 4-wheel drive maintenance or something like that.

Where they check and change fluids... perhaps tranny incase its not red anymore?

[MarK M]

Originally Posted by evldave

How many miles do you have? I'm starting to see more people make comments about cooling issues (and it's getting close to summer). Not a lot yet, but it's starting to warm up here, I've got 11k miles on my rig, and the 'stabilized' temperature I'm seeing is noticeably higher in the warmer weather with more miles on my rig. It's supposed to be 100 here in a few days, guess we'll see.

I have roughly 15K miles on the 3.

[HummerNewbie]

Originally Posted by MarK M

one more thing... I've wheeled several times since i got the 3.

Is the radiator maybe caked with mud? Have you hosed it out good?

[f5fstop]

Originally Posted by MarK M

I have roughly 15K miles on the 3.

When did you get it, if before August of last year, did the dealer add the extra t/case fluid? If not, might be a good idea to at least have them add the extra fluid.
Axles are synthetic, should be good for a while yet.

[Michael1]

Originally Posted by f5fstop

Other point, if you are driving at speeds above 30-40 mph, no fan in the world can draw any more airflow through the radiator, than what is being pushed in by the movement of the vehicle.

I don't know about modern trucks, but in the old days (70's, early 80's), there were some clutched fans on GM's Heavy Duty Cooling Systems that would drop radiator temperature even at 60-65 mph. It sounded like a jet engine when it engaged, and I believe it took about 10 hp to run. That might be a bit much for the little H3 engine. I think the aerodynamics are better on today's vehicles with respect to cooling system air flow, so such "big mutha" fans aren't needed.

As I told someone on another thread, if the sensor is ok, have the dealer to a drain and then a Vac-and-fill of the coolant system. If there is a possible air bubble in the engine, it can cause overheating, and this has been a problem with some of the Ecotec 4-cylinder engines.

Do all of the dealers have "vac-and-fill" systems now?

It can be a real bear getting some cooling systems voided of air, and it definitely can cause overheating. Some GM vehicles have air bleed valves which help some.

Michael

[HummerNewbie]

Originally Posted by Michael1

I think the aerodynamics are better on today's vehicles with respect to cooling system air flow...

Seems funny to here "aerodynamics are better" in a discussion about Hummers. I know you were talking about the cooling system but they just seem funny in the same conversation

[Michael1]

Originally Posted by evldave

hmmm, maybe I should turn off my DRLs, thereby reducing the load on the engine and possibly lowering the likelihood of overheating.

WAIT! The DRLs are causing the overheating. Can you imagine the amount of extra heat produced by all these cars using DRLs? It's not greenhouse gases causing global warming, it's Daytime Running Lights! OHMYGOD! We need to put a stop to these DRLs now, before we pass along a legacy of wanton waste to the next generation of car buyers

Wrong thread, Dave!!! But I like your sense of ingenuity. Don't worry. I'll get back over there. I know you guys are chomping at the bit.

Michael

[evldave]

Originally Posted by Michael1

Wrong thread, Dave!!! But I like your sense of ingenuity. Don't worry. I'll get back over there. I know you guys are chomping at the bit.

Michael

What pisses me off more than anything is I've spent a couple hours this week looking up NHTSA and other reports just because of that. Of course, it was at work, so it's not like it was getting in the way of anything important. You are getting closer to redeeming yourself for your obsessive anger at DRLs, but not yet...

[KenP]

What was your trans temp doing? If the trans gets hot, that will raise your engine temp. PhilD had to install another trans cooler, but since you're stock you shouldn't have that problem.

Just make sure to check that temp before you take the truck in if you can. It'll be good info for the tech and may save him a step or two.

[f5fstop]

Originally Posted by Michael1

I don't know about modern trucks, but in the old days (70's, early 80's), there were some clutched fans on GM's Heavy Duty Cooling Systems that would drop radiator temperature even at 60-65 mph. It sounded like a jet engine when it engaged, and I believe it took about 10 hp to run. That might be a bit much for the little H3 engine. I think the aerodynamics are better on today's vehicles with respect to cooling system air flow, so such "big mutha" fans aren't needed.



Do all of the dealers have "vac-and-fill" systems now?

It can be a real bear getting some cooling systems voided of air, and it definitely can cause overheating. Some GM vehicles have air bleed valves which help some.

Michael

The H3 has a large grille opening for air flow, max airflow through the radiator will be forced it at speeds. Now on the C5 Vettes with no openings in the front for airflow, just the lower air flow deflector, fans will turn on at speeds to help draw air through the radiator.

GM recommends Vac-and-fill for all vehicles now, but not a requirement; yet.

[f5fstop]

Originally Posted by evldave

What pisses me off more than anything is I've spent a couple hours this week looking up NHTSA and other reports just because of that. Of course, it was at work, so it's not like it was getting in the way of anything important. You are getting closer to redeeming yourself for your obsessive anger at DRLs, but not yet...

You guys still discussing this subject? If so, just don't look at NHTSA, look at European and Canadian Data, that is where the idea first took fruit. They were the ones who pushed it. NHTSA has looked, but made no decision on requirements; yet.
Problem I found with that discussion is not whether or not DRLs are worth it, it was the idea that $3.00 in fuel per year was a logical reason to have them disabled on a Hummer.

[evldave]

Originally Posted by f5fstop

...
Problem I found with that discussion is not whether or not DRLs are worth it, it was the idea that $3.00 in fuel per year was a logical reason to have them disabled on a Hummer.

Ah, but now we've found that DRLs are contributing to global warming! This must stop! I'm surprised the uber-liberal EU hasn't caught on to this and stopped their use altogether.

I'm sure DRLs are also the cause of deforestation in the rain forests of the Amazon, genocide in Uganda, and the fall of the Roman Empite. Just haven't found any studies to back those up: yet.