Too warm for winter cover?

[npauli]

Q. When is it too warm to have a LB7 winter cover on? (when you're not towing or hauling).

A. Just learned today. When it's in the 60's outside, the coolant temp seems okay (not much over 200F), the fuel economy is wonderful, but the passenger's side battery starts bleeding some goo around the positive post. That's enough motivation for me to take off the cover, and take it off a little sooner next year.

Anybody know of anything that would be bothered by heat worse than that battery? An infrared gun measured temps ~ 150F on a lot of underhood components.

[lmholmes11]

I have always heard that you shouldn't use the winter cover if the outside air temp is above 30 degrees or so. Regardless if towing or not. If you do want to keep the cover on, at least fold down a corner, or make it so there can get some airflow in. I live in Michigan, and i travel up to the Upper Peninsula (-10 F average) and i have never even had to use, or felt the need to use the cover. It always starts right up.

[Mark Rinker]

60 degrees is way too warm to have the cover on. You might see some temporary, artificial benefits like some mileage increase, but your cylinder head temps are probably too hot, and there are alot of electronics that live under the hood...not advisable. I'd follow the GM owner's manual on this one.

As for the second comment regarding starting - that has nothing to do with the benefit of running the winter front. You're wasting ALOT of fuel by not running it when its -10 out, through heat losses.

Other than that, the DMax will make cabin heat and keep water temps in a normal range, even when its that cold out.

[More Power]

Q. When is it too warm to have a LB7 winter cover on? (when you're not towing or hauling).

A. Just learned today. When it's in the 60's outside, the coolant temp seems okay (not much over 200F), the fuel economy is wonderful, but the passenger's side battery starts bleeding some goo around the positive post. That's enough motivation for me to take off the cover, and take it off a little sooner next year.


Was the battery hot to the touch?

Open the hood after towing on the interstate on a hot summer day. It gets really hot under there....

Jim

[Mark Rinker]

Was the battery hot to the touch?

Open the hood after towing on the interstate on a hot summer day. It gets really hot under there....

Jim

Its unbelievably hot, when towing AND its above 80 degress out. But...there is still lots of (relatively cooler) airflow, even at 80 or 90 degree outdoor temps, coming through the cooler stack and then past the engine, carrying away heat from cylinder heads, turbo, and exhaust manifolds - rushing around the engine and carrying heat down and under the moving truck.

Never was this more clear than the day last summer that a GM Service Advisor and I went for a ride in my Kodiak with the doghouse off, in search of an exhaust leak. You could not stay in the cab of the truck, even with all four windows open, and the A/C on. We were both amazed at the VOLUME and the HEAT that rushed past that engine (in this case, into the passenger compartment) when the truck was rolling. The faster you went, the more impossible it became to even breath - it was THAT hot.

There is more air cooling going on while underway than we can easily measure. In the winter, this effect is a negative - too much super cold air robs your engine of efficiency by carrying away heat from the engine compartment, faster than the engine can maintain it. The cost is fuel, and in some cases, drivability as it can cause fuel filter freezing under extreme conditions.

The winter front completely interrupts this air-cooling affect, and underhood air cooling then relies only on what the fan can pull through the cooler stack. To make things worse, the fan clutch doesn't react properly to the engine temps building behind it, it only reacts to the temperature of the air coming over the stack.

The passenger side battery always is the one that gets baked, in our experience with 2001-2006 Duramaxes. It lives in a bad place for airflow, even when the winter front is off. Most of our passenger side batteries will boil a little acid out the vent in the summer while towing. They are always the first to fail - in the four pairs of AC Delcos we've replaced, the passenger side tested bad 100% of the time, and the driver side was still good.