Engine temp

[JMVH2]

OK, I went up north for the weekend (MI) for a total of 350 miles one way, I was pulling a 6 x 12 enclosed trailer with 2 motorcycles for a total weight of 2800 lbs. speed about 65 mph on the interstate ; MI is very flat very few hills, the tranny oil temp was always below 1/2 on the gauge (below 200 F) the engine coolant gauge always runs below half at about 195 to 200 F this time it went up to 235F with and/or without AC ambient temperature at 95 F. Why it will do that? Very minimal weight pulled? All fluids are OK and recently replaced, the truck only has 41000 miles.

[KenP]

Just guessing, but 95* is pretty darn hot. That's likely the only reason.

[Hummie2]

My truck is also an 03 and is marginal on cooling @95F ambient anymore. It never used to be that way. I am wondering if 3yrs worth of oxidation is starting to take its toll on the aluminum radiator fins. It may not transfer heat as well as it used to. I had it get hot off-road @100F recently, never had any problem in the past. Might be time for a bright shinny new radiator.

[kdio]

I always had trouble with my H2 running hot. I had everything check and even did a flow test on the radiator but everything check out normal. I finally decided to replace the radiator with a Ron Davis Aluminum Radiator. It is a direct replacement and it solved all my problems. My temperature now never goes above 190 degrees and the transmission runs at about 175 degrees. When you see the size of the radiator that GM puts in the H2, you will be amazed how small it is. It is onlt 1 inch thick. Magna Charger said they have heard of a lot of customers complaining about their H2 running hot and they are the ones that recommended the Ron Davis Radiator.

[Fubar]

Originally Posted by kdio

I always had trouble with my H2 running hot. I had everything check and even did a flow test on the radiator but everything check out normal. I finally decided to replace the radiator with a Ron Davis Aluminum Radiator. It is a direct replacement and it solved all my problems. My temperature now never goes above 190 degrees and the transmission runs at about 175 degrees. When you see the size of the radiator that GM puts in the H2, you will be amazed how small it is. It is onlt 1 inch thick. Magna Charger said they have heard of a lot of customers complaining about their H2 running hot and they are the ones that recommended the Ron Davis Radiator.

Kdio, happy to hear your cooling issues have been resolved. It is funny that Magna Charger is recommending a product that there warranty companies says will void the magnason warranty. Personally I don't know why changing a radiator would void the warranty but then I also don't understand how a valve guide sucked into one of the heads isn't covered under warranty because it is "Not an internal engine component" ?? Just one of the many excuses I heard when I had my troubles with Magna chargers extended warranty company.

When I spoke with the folks at Rod Davis I was told that their product was never intended to be in a daily driver that it had been developed for racing applications and was to be treated as a disposable commodity being changed out every few races. Perhaps I was told this because I came to them with an existing problem and they didn't want the liability, don't know.

But with that info in mind while I was sitting at Cerritos Hummer one day waiting for Magna Chargers extended warranty folks to come out and look at my truck 3 H2's were brought in on flat bed haulers all with Rod Davis radiators and all experiencing the same trouble, busted inner-cores or so the tech and service manager said. They went on to say that they refuse to install the Ron Davis radiators any longer and are swapping out the ones that come in with ones that are made of the same material as the stock unit just 2 inches wider and holding 3 extra gallons.

I wish you all the best of luck with your Ron Davis radiator. Perhaps with any production run there are problem units and perhaps Cerritos Hummer got a hold of 3 of these units and they all just happened to fail at the same time. Fell free to contact Mike the service manager at Cerritos Hummer if you'd like to confirm any of this. It is possible that you will never have any issues with your radiator. It just seamed strange to see 3 fail and all be brought in within a few hours of one another.