Hi guys,

I have a 2011 Silverado Hybrid and I have a questions about heat.

Twice now I have seen the gauge go above the "normal" spot (which is the 12 o'clock position marked as 210 degrees).

The first time was in death valley while 4x4 mode at low speeds - frankly that did not surprise me since there is so little airflow. I turned off A/C and switched transmission to Manual mode. Trans temps peaked at about 170, coolant peaked at about 245 (on scangauge).

The second time was Friday (6/7) driving up the I-5 grapevine from the Valley side into LA. The temperature in the Valley was 103-105 and the Temp on the LA side was high 80s. I had been driving across the valley at 75-85 mph from north of Sacramento with the A/C on (i.e. about 5.5 hours) - but the needle stayed in the normal range until I reached the grapevine. As soon as I began the climb the needle move well above "normal" and I turned off the A/C. I did not have my scanguage hooked up but the temp was higher then I have seen before and I would put it above 245. The needle was about 7/8th of the way to the top pin marked as 260 on the gauge. Trans temp peak was 167 (which I consider normal for a long grade). I had no leaks, low fluids or warning lights. Temperature dropped to normal as soon as I got over the hill at Gorman and stayed normal. The truck was not towing and I was the only passenger, although I did have my full off road safety kit (Hi lift jack, air compressor, tow chains, axes, sledge hammer) and some luggage (500 lbs total cargo weight). On the return trip it was cooler (70s on the north bound climb) and the temp was normal the whole way.

I would be interested in any thoughts on if they was "normal" and any advice on improving cooling on this truck.

Thanks.

 

If you would have hit engine coolant of ~ 125C 257F the AC should have turned itself off and the DIC would have complained. Same goes for trans fluid I believe above 105 or more C.

No Cottonwood fuzzies in the grille or radiator? Around me I need to peel the blanket off the outside AC unit.

 

Good to know the setpoints. I got nothing on the DIC so I will call it ok.

I have thought about clearing the debris off the radiator - it has the usually collection of bugs and small rocks from 70k miles of use.

Any thoughts about adding an oil cooler?

 

The GM Small Block has a 2-bolt aluminum cover just above the engine oil filter. It is removed when the factory oil cooler is installed.

If you were going to rev the engine up in the heat > 3500 rpm under heavy load, I would look into the adaptor, plumbing, and cooler used on the non-hybrids. All factory parts.

 

Interesting. Having moved from the Coast to the Central Valley (115 is a normal summer high) and climbing the other passes over the Sierra every few weeks I might look into that option.

 

I love the internet -

http://www.lingenfelter.com/mm5/merc...=#.UbeG7efbNIE

"The Lingenfelter oil cooler adapter is designed to allow the installation of an oil engine oil cooler on GM Gen IV V8 engines including the LS1, LS2, LS3, LS6, LS7. The LPE adapter is machined from a single piece of 6061 aluminum and is then black hard coat anodized for additional durability. The adapter features -10 fitting for the oil inlet/outlets along with a port for the oil temperature sensor and oil feed line. This adapter was specifically designed to reduce oil pressure drop over other designs on the market, retains the factory oil filter location & includes gasket and bolts. Oil exiting the adapter is filtered oil."

 

That's quite a lot for just the adapter block. I'd be tempted to fire up the old Bridgeport and whittle out my own for $100.