Cooling Issues

[4speedfunk]

Knock on wood...my 08-5cyl has been rock steady since day one but, there are WAY too many discussions about H3 cooling systems. I know Alphas run hot. I've seen it on numerous H3's so I think there is some merit to those complaints. But not the 5-cylinder. No way. There should be plenty of cooling available with the stock system.

There seems to be a culture among Hummer owners that more money means more performance. And its never been more pronounced, than it is with the cooling system. Seriously...there are some crazy ideas & suggestions floating around about how to solve a hot-running H3. Everything from cutting holes in the hood, to adding fans, high-dollar aluminum radiators, and messing with ECM settings. Its quite entertaining to read about these mods but, its also sad that some people buy into the b.s. and end up blowing hundreds of dollars on their cooling system for virtually no reason at all.

Unlike the rest of the H3...the cooling system is super old-school, and its not that hard (or expensive) to get it working correctly. I honestly don't understand the need to "get tricky" with it. You can replace the ENTIRE cooling system for very little money, and return it to factory spec. and it should perform perfectly. If it doesn't...something is wrong. No amount of radiator, e-fan, clutch, pcm tuning, thermostat, blah blah blah is going to fix it. If it does...then you are most likely masking the real cause of the overheating, rather than simply fixing the original problem.

 

[Hopkins86]

https://vimeo.com/173274777


Sent from my iPhone using Tapatalk

 

[Hopkins86]

If I don't have my blower motor on the fan don't run till the temp gets to 3/4 on temp gauge


Sent from my iPhone using Tapatalk

 

[Hopkins86]

Sorry 4 the poor video skills https://vimeo.com/173275313


Sent from my iPhone using Tapatalk

 

[SedonaBound]

There seems to be a culture among Hummer owners that more money means more performance. And its never been more pronounced, than it is with the cooling system.

It's a disease that's certainly not limited to Hummer owners. :giggle: The answer to chronic hot running is a larger or more efficient radiator that can shed more BTUs. Aftermarket e-fans are band-aids that only help at low speed. I know that for fan efficiency, blade design is critical but the e-fans I've seen look like they were designed by a marketing dept. FWIW, I've had two H3s; a 3.5 and a 5.3; both rock steady in the middle of the temp gauge whether in Phoenix traffic at 110 degrees or on the trail in 4L.

A study of rig mods vs. cooling issues would be interesting but the sample on a forum is probably too small to be definitive. If I was thinking of an e-fan, I'd hit the salvage yard with my clearance dimensions in hand, and look for one from an import SUV/truck that would fit.

 

[amrg]

The V8 has a setup that works perfectly. 2 small cooling fans infront of the condensor were perfect setup for me (SA model). Offroading at 110+ weather was no problem at all and temps were always in check.
Sadly with the new engine setup, the intake manifold sits 3" lower and as a result the clutch fan blades dont clear the intake tubing at all. This issue was existent with the stock manifold but the stock intake tube has a small dent molded into the plastic part going into the tb to clear the fan blades.

 

[rsc]

If I don't have my blower motor on the fan don't run till the temp gets to 3/4 on temp gauge


Sent from my iPhone using Tapatalk

The a/c triggers the fan because without airflow across the a/c fins it will quit cooling right away. The fact that the fan only comes on at 3/4 on the gauge means that the gauge needs calibration. 1/2 on the gauge could be 198 or 202 or 210 or anything really. On the 3 H3's I have, the temps measured with a scangauge through the OBD II port have a displayed temp spread of 12 degrees. As Doc Olds loves to say, it's just an idiot light with a gauge attached. Gauge temp means nothing, actual numbers do. Find out real numbers and quit worrying unless it's running close to 240F.

 

[Hopkins86]

Ok I just put my scan tool on it here is the pics I took

Sent from my iPhone using Tapatalk

 

[Hopkins86]

Ok I just put my scan tool on it here is the pics I took

Sent from my iPhone using Tapatalk

The 3/4 temp gauge is only hitting 221


Sent from my iPhone using Tapatalk

 

[Hopkins86]

The 3/4 temp gauge is only hitting 221


Sent from my iPhone using Tapatalk

So how do I fix my gauge can it be recalibrate or do I have to get a new one I didn't see that in my scan tool but I don't have that if a advance tool


Sent from my iPhone using Tapatalk

 

[JPaul]

Why are you registering 127 degree intake temps? That seems awfully high. Also, that E fan setup looks awful, the fan is only pulling air through a very small portion of the radiator. The rest of the radiator's airflow is effectively blocked everywhere else other than the fan opening and a few 2"x3" openings, so even at highway speed when the fan is unused it still won't have enough cooling efficiency. It really should not be using a completely flat piece of aluminum plate, it should be formed plastic that would still allow airflow from the rest of the radiator.

I also think if you're going to use electric fans on anything over 2 liters you should have two fans at a minimum, unless you are just adding a pusher fan to aid the stock mechanical fan. Even my 98 Dodge Neon had two fans on the DOHC 2.0L (the SOHC 2.0 only had one fan). And by simply upping the engine to a 2.4L engine it didn't have enough airflow to cool the engine if I was in stop and go traffic and had the AC on in high temperatures. And the radiator was brand new and the engine newly rebuilt, so it wasn't anything wrong with the cooling system itself.

Regardless of all that though, have you tried talking to pcm of NC about it? If you bought it new from them they should be providing you with support for their product, not us.

Sent from my Nexus 7 using Tapatalk

 

[Hopkins86]

Why are you registering 127 degree intake temps? That seems awfully high. Also, that E fan setup looks awful, the fan is only pulling air through a very small portion of the radiator. The rest of the radiator's airflow is effectively blocked everywhere else other than the fan opening and a few 2"x3" openings, so even at highway speed when the fan is unused it still won't have enough cooling efficiency. It really should not be using a completely flat piece of aluminum plate, it should be formed plastic that would still allow airflow from the rest of the radiator.

I also think if you're going to use electric fans on anything over 2 liters you should have two fans at a minimum, unless you are just adding a pusher fan to aid the stock mechanical fan. Even my 98 Dodge Neon had two fans on the DOHC 2.0L (the SOHC 2.0 only had one fan). And by simply upping the engine to a 2.4L engine it didn't have enough airflow to cool the engine if I was in stop and go traffic and had the AC on in high temperatures. And the radiator was brand new and the engine newly rebuilt, so it wasn't anything wrong with the cooling system itself.

Regardless of all that though, have you tried talking to pcm of NC about it? If you bought it new from them they should be providing you with support for their product, not us.

Sent from my Nexus 7 using Tapatalk

Yep I think it's time to yank it out I left them a message sent a email haven't got any reply back yet


Sent from my iPhone using Tapatalk