"Alert: Engine Oil Hot, Action Required: Idle Engine"

nando87 · May 27, 2014

This past weekend we went camping and towed our toy hauler to the mountains to get away from this AZ heat. When going up a long grade about 3/4 the way up I got a warning that appeared in my center screen.

I started the hill climb at 65mph, the truck then loss speed to about 53mph and downshifted. It was able to get back to 60mph but then that's when I got the warning.

Has anyone else experienced this?

The new motors have over 8qt. of oil and oil jets for cooling, I wouldn't think that this would be an issue.

I use to have an 07 with a V-Max with the NHT package (4:10 gears) and I never had this warning come up and I've towed in a lot hotter weather and steeper grades.

Edited May 28, 2014 by txab
edit title

Jon A · May 27, 2014

Interesting, that’s the first heat-related issue I’ve heard of on one of these trucks. Of course most of us haven’t towed anything in the summer with them yet so I’d say their cooling systems aren’t yet proven.

What are the specs on yours (engine, axle ratio, Max Tow, etc)?

The stock fan settings are really relaxed and let the engine and oil get pretty warm. The most simple upgrade is a tune to turn them on more aggressively with coolant and oil temp. Once lower temperature thermostats are available we’ll be able to be even more aggressive. Hopefully the stock radiator and oil cooler will prove sufficient with enough fan and a little more breathing room from a cooler thermostat.

sourdough44 · May 28, 2014

It may depend on particulars, length if grade, trailer weight, temp, driving technique and the rest. Did you turn the A/C off before the grade? I'd also take it easy on the gas pedal. There may be add-ons you could get to help with cooling.

In general, a more heavy weight truck can handle adverse conditions better, 2500 HD as an example.

nando87 · May 29, 2014

Interesting, thats the first heat-related issue Ive heard of on one of these trucks. Of course most of us havent towed anything in the summer with them yet so Id say their cooling systems arent yet proven.

What are the specs on yours (engine, axle ratio, Max Tow, etc)?

The stock fan settings are really relaxed and let the engine and oil get pretty warm. The most simple upgrade is a tune to turn them on more aggressively with coolant and oil temp. Once lower temperature thermostats are available well be able to be even more aggressive. Hopefully the stock radiator and oil cooler will prove sufficient with enough fan and a little more breathing room from a cooler thermostat.

Mine is a 5.3 with 3.42 crew cab 4x4.

The water temp and tranny temp weren't very hot so the fans were doing their job I think. The oil temp was another issue, I really hope this isn't an issue going forward with these new trucks.

And yes, the A/C was off for the whole trip.

I was WOT, if not I would have been going 40mph up hill. I had already lost like 12mph by mid grade and when she finally down shifted I was able to climb back to 60mph but then I got the warning.

Jon A · May 29, 2014

Thanks for the info. I wouldn't be too quick to assume the fans were doing all they could for a couple reasons.

The biggest reason is the oil cooler on these trucks is actually an in-tank water/oil cooler in the cold side tank of the radiator. The faster those fans are blowing, the colder the water in that tank will be. The colder that water is, the better the oil cooler is going to work. If your water temp was 210 (not very likely), with your A/C off your fans are only spinning at about 10% speed--in other words, doing very little.

Running in those conditions at 210 is unlikely as these engines heat up fast even in much less demanding conditions--but the stock dash water temp gauge hides this fact. The Denali gauge won't move off the 210 mark until water temp exceeds 225--and it's digital so it reads exactly how GM wants it to read. I haven't tested the Chevy gauge to see exactly how it moves but they all have a "dead spot" around 210 so the chances are very high you were running at least somewhere close to 220 even if the gauge hadn't moved much. At that temp the stock programming still only has the fans running at less than 25%.

That matters because the water in the cold side of the radiator could be close to 200 degrees under those conditions. Even with the stock thermostat, having the fans on close to max could drop that temp by 20-30 degrees which will make it cool the oil much better. With a cooler thermostat you can have the fans come on 100% at a much lower temp. With stock programming they don't come on 100% until the engine is running 244 degrees. Also a cooler thermostat means your water and oil are cooler at the bottom of the hill before you go up giving you a larger safety buffer.

Anyway, that's why I think the stock performance could be improved upon significantly without spending big bucks on new parts. Of course it's possible the oil cooler just isn't good enough--I think we'll know a lot more after this summer as everybody gets a chance to tow in hot weather. Hopefully this was a one-off aberration in your case, but unless something's broken, it doens't bode well running into this issue in May.

nando87 · May 29, 2014

My temp gauge was at the 1/4 mark before hot, so it differently was moving past 210 deg.

Like you said, hopefully this was a one off event but it's only May and the outside temp was only in the 90's.

Never had this issue in my 07 towing the same trailer and rout.

Jon A · May 29, 2014

OK, your water was probably 230+ then. That's getting warm but still OK, but it's not going to cool your oil very well. Even at 234 degrees your fans are still on at less than 50% power with stock programming so that's what I see as the biggest area for improvement without changing any hardware. I have mine set to be at 100% by 226 degrees which I think is a much more reasonable setting with the stock thermostat.

It'll be interesting to see if this is a common issue with these trucks as we go through the summer months. Hopefully not but now you have me worried.

nando87 · May 29, 2014

How did you change your fan engagement temps? I have a buddy that tunes with HPTuners that can do it but I don't want to void my warranty already.

Jon A · May 29, 2014

I used HP Tuners, it is detectable by the dealer. Diablo claims (and it seems legit) their programmer is not detectable so that's probably the safest way to reprogram.

Something else you can try--and it sounds counter-intuitive--is cranking your A/C. While that adds heat to the system, it also speeds up the fans depending upon the pressure of the system (easy to get it to a high pressure on a hot day). There's another fan table just for that. For some conditions, the added speed of the fan will remove more heat than the A/C adds. It's not ideal, but it's something else to try short of reprogramming.

In SAE J2807 (the new towing test standard the manufacturers might finally adopt) the toughest desert hill climb test (12 miles up Davis Damn grade with ambient temps over 100 degrees) is done with the A/C cranked which is naturally supposed to make it more difficult. But one can see how that isn't necessarily the case depending upon how they program the fans.

Anyway, good luck and keep us updated. Most of us haven't had any hot weather yet with the trucks so you're a good canary in a coal mine for us.

nando87 · May 30, 2014

I'll have to look into the Diablo since the dealer can't detect it. I would hate to use HPT and for some reason my motor go out and I voided my warranty just because I was trying to compensate for a flaw in the cooling system.

fondupot · May 30, 2014

How many miles on your truck? What oil were you using?

nando87 · May 30, 2014

How many miles on your truck? What oil were you using?

2500 Miles, whatever the Dealer puts in.

fondupot · May 30, 2014

2500 Miles, whatever the Dealer puts in.

I wonder if somehow they put in 0w30 instead of 0w20. Since that 0W30 is slightly thicker...it retains more heat and then causes the message? Just spit balling...not trying to make you paranoid.

Edited May 31, 2014 by fondupot