H3 Alpha engine temp

[fowlken8]

I've noticed that my alpha gets up to temp very quick. Faster than my other vehicles. And given the southwest heat wave, idling with AC on it passes halfway and climbs.

I know the gauge isn't perfect. We can probably survive up to 3/4 on the gauge... But I don't like it.

Turning off the AC or driving always makes the temp go back to under halfway.

I am planning on towing a bumper pull trailer for camping in September and want to avoid any possibility of overheating. Heading north in NM there are some very steep, long, grades. This 5.3 feels nothing like my supercharged 5.6l titan. And I expected that. But I'm not confident.

All cooling components check out. Is this just a hotter engine? Is this unusual heat wave the culprit?

 

[Alpha X]

Rather than rely on where the instrument panel gauge is pointing, you may want to add a ScanGauge (or UltraGauge or similar gauge) for more accurate temp numbers for engine, transmission, etc. See this link below for some discussion about the Alpha codes to display the info.

See here:

Transmission Fluid Temperature using a ScanGauge X-Gauge in a 2010 Alpha

Make your Trans Fluid Temp display in a 2010 H3T Alpha, using CANSF. The 2010 has the LH9 5.3L V8, 2009 has the LH8. If you go by what ScanGauge lists on their website, it won't work in an Alpha because I believe the code for the I-5. You might get it to read "32". That's not correct. Use...

hummer4x4offroad.com

.

 

[alrock]

Have you considered replacing your fan clutch? If it's having trouble at idle vs. when driving, that could be the culprit.

That said, in my I5 it can't handle 110 degrees plus with a/c on at idle. I have to keep the RPMs at 2000 or above. Even though the Alpha and the I5 share the same radiator, the Alphas seem to cool a bit better than the I5. I think your Alpha should be able to handle this heat, at least reasonably well. Heck, my work-supplied Ford Fusion doesn't have any problem at these temps.

 

[fowlken8]

The fan clutch seems OK with thr hand spin test. It's really hit and miss. Made me wonder if there were any air bubbles so I did the silly elevated front end, squeeze radiator hose trick to see if any bubbles came out and no. It goes just above half way. And this is when not moving at all for 10-20 minutes. I hate using gauges and I have an ultra gauge somewhere.... Same as my titan, the oil pressure gauge just floats and it's scary...but apparently it's a real time gauge and they've since removed it due to buyer concerns haha

 

[alrock]

Just above halfway is pretty much where GM spec'd the temp gauge to read. It's normal. Hitting 3/4 is less normal but we're also dealing with some exceptional weather in many places right now.

 

[alrock]

Alright, I scienced the sh*t out of this today. Took a thermocouple and measured air temps coming out of my upper vents with a/c on and recirc on. The H3 was parked outside but not in the direct sun. My a/c was rebuilt by Reloader 15,000 miles/2 and a half years ago, replacing everything in front of the firewall. Radiator was replaced not long before that, and fan clutch not too long ago.

When I started up today, it was 106° outside. Within about a mile, the a/c temp was about 50°. Once I got on the freeway, the engine was warmed up and the temp gauge was showing 2 clicks above half. The a/c dropped to 48° and then slowly continued to drop where it ended up maintaining an output between 43.3° and 43.8°, with one drop to 42.9°. Once I got near my destination, the a/c jumped back into the low 50s. Once I parked and left the engine running, it was 60° within 60 seconds. The temp gauge hovered between 2 and 3 ticks above halfway.

When I got back in, it took about a mile and a half for the a/c to drop to 53°, in part I think to the heat soaked engine compartment, condenser, etc. On the way home, the outside temp was 108° and the a/c never got below 46°. Once I got on surface streets it ran in the low 50s, jumped up to about 63° when I parked at an ATM, but then dropped back into the upper 40s when I started driving again.

At every stoplight it would jump up and drop back down when driving. That's fine with me for spread out lights, but when I'm in a more compact part of the city the a/c won't cool down much as I spend more time stopped and less time with significant airflow through the condenser. I did test 2000 RPM for about 60 seconds and the a/c temps hovered about 54° and the temp gauge didn't rise up to 3/4 as it might at longer stop lights.

To validate the intense science behind this, I'll add some key words like control, variables, delta, calibration and ANSI.

 

[fowlken8]

thank you sir. I admit I do not have any knowledge in the 5.3L. I'm a 3.7L guy for my past 3 H3s. it could be normal. I just never saw any of my other 3's gauge get to even half. If this is normal, I just need to adjust my expectations