Overheating duramax/ roaring fan/ steering stiff

[djdave33]

I have a 2005 duramax duelly. I have had it overheat pulling a 3000lb trailer when it was 75 degrees outside. I have it overheat unloaded and no trailer at 95 degree temp. The cooling fan starts to roar and the temp gauge keeps climbing untill the dic starts to flash coolant hot. Took to dealer on several occasions they changed the cooling fan assembly 2 times and then changed out the air cleaner assembly from a 2006 lmn but my truck will still overheat and sound like a SCHOOL BUS. I also have a problem with the steering issues. Namely the hard stiff steering at slow parking lot speeds and or when the truck is stopped and try to turn the steering wheel. It turns ok for about half of the wheel travel then it gets so stiff and looses power assist. I have had a new power steering pump installed, new steering gear assembly and was also told on one occasion that one of my tires was a few lbs to low on air that was causing me troubles. Imagine that on a $51000 truck that starting haveing these issues at 1613 miles.. The truck now has 21000 miles on it and I am afraid to use it anymore because I dont want to jeopardize my familys lives driving something that could leave us stranded on the side of the road somewhere. Gm states it can not duplicate some of the problems but the mechanics pull me to the side and say there are a (lot of complaints) about the same problems Iam having.
The truck is a 3500 hd DRW 4x4 with all the heavy duty towing packages and coolers.
I am hoping someone on here would have some suggestions as the truck now just sits in my garage unused.

thanks for any help,
David

[djdave33]

Any ideas from anyone???

[member12]

there are other members here that can help more than I can.

If your electrical fan turns on, then we need to figure out why. Perhaps a stuck thermostat?

Does it cause a problem in heavy traffic or slow speeds when towing a heavy load? It could also be a transmission cooling fan.

GMCsonoma and Shadams are know pretty much everything about everything related to any GM truck, and I'm sure they'll post soon.

Theres a bunch of responses in the other thread you started about this.

[djdave33]

Originally Posted by member12

there are other members here that can help more than I can.

If your electrical fan turns on, then we need to figure out why. Perhaps a stuck thermostat?

Does it cause a problem in heavy traffic or slow speeds when towing a heavy load? It could also be a transmission cooling fan.

GMCsonoma and Shadams are know pretty much everything about everything related to any GM truck, and I'm sure they'll post soon.

Theres a bunch of responses in the other thread you started about this.

I dont remember starting another post.. but maybe I did.. Anyways the diesels dont have an electric fan its a belt driven clutch fan. I have had a bunch of things done under warranty and its still under factory bumper to bumper. It has had 2 new clutch fans installed, new programming, an air cleaner assembly from a 2006.. As for the hard steering problem.. it has had a new flow valve for the power steering pump, a new power steering pump, then a new steering gear assembly, then another new steering gear assembly. I am still having overheating problems and steering problems..

[shadams]

Were there any DTC's set? There are quite a few reasons the engine could overheat other then a failed cooling fan clutch. I wonder if the fan is always on because the engine is alwys running hot? This is from the engine overheats diag:

This condition may be caused by any of the following possibilities:

• Installation of an aftermarket grille.

• A plugged charge air cooler.

• Fan clutch not operating properly.

• Drive belt slip.

• An overfilled transmission.

• Turbocharger not operating properly.

• A plugged air filter.

Do you know if they verified any of these other things? I have only had one other Duramax with those types of problems but he was really working that thing much harder then you state you are.

As far as the steering goes, it sounds like they have thrown a bunch of parts at it instead of telling you that it may be normal. Now of cousre, without feeling it, I really cant say that it's normal, but here is the info in the service manual about what you mention. Notice the part where it says replace the flow control valve, you said they replaced that, right?

A lack of steering assist could occur if the brakes are applied and turning the steering wheel with the vehicle stopped or during parking lot type maneuvers. This concern can be aggravated by worn tires, low tire air pressure, low power steering pump pressures, and tires larger than stock size. In some cases, where the power steering pump pressures are at the low end of the specification, replacing the power steering flow control valve with P/N 26095470 may improve the concern.

The other thing is this vehicle has hydroboost braking, which means it uses power steering fluid pressure to assist in braking instead of engine vacuum, its possible there is a problem there contributing to the lack of assist.

[djdave33]

Hi,
Thanks for the reply..
My truck is all stock grill and no power programmers or exhaust ever.. I have had it at several dealerships and some of them have not been able to duplicate it.. I have had the fan clutch changed 2 different times under warranty. I also have had the air cleaner assembly from a 2006 lbz installed under warranty. It still overheats alough it helped a little bit with the a/c assembly. I am trying to find how to reasonably solve all the problems with my duramax lly overheating issues. The truck sits in my garage with 21k miles on it. It is still under fact warranty. The belts are not slipping actually I was thinking the fan seems to be running to fast and loses some efficiency by spinning so fast. I know about the hydroboost thing I formorly had a 2001 3500 8.1 with allison, same braking system but I never had the hard stiff steering with that truck or any overheating problems.
Any help would be greatly appreciated..

Thanks,
Dave

[djdave33]

Im sorry i didnt see the rest of your reply..

Yes they did replace the steering flow control valve one time and they said it made it worse to the effect it had no assist at all.. I dont know if its normal or not but the pump squeels and is stiff as**** to turn.. its really bad..

thanks,
Dave

[shadams]

Strange....I dont see how, if it comes in with the problem, they couldnt fix something like that. Sounds like there is a restriction somewhere. I wonder if they actually did a PS pressure test rather then just replacing that valve?

[djdave33]

Im reading from the r/o
Steering/supensionn hours3.5

customer states: loses power steering
PERFORMED PRESSURE TEST ON POWER STEERING AT 245 PSI AT IDLE. 3 LITERS A MINUTE. FOUND PIT33860 WHEN PRESSURE IS AT LOWER SIDE OF SPEC
REPLACED FLOW CONTROL VALVE AS STATED IN PIT33860:::: MADE CONDITION WORSE. HAD NO POWER ASSIST.
CALLED TECH ASSISTANCE. THEY STATED TO REINSTALL ORIGINAL FLOW CONTROL VALVE STATED THIS IS A CHARACTERISTIC OF THIS VEHICLE..

that is the exact wording on the r/o


any ideas?

thanks,
Dave