I hope the 6.5L fleet does not revolt....

[GM Guy]

So, got it half way home today, was riding with a friend and needed to help him get a truck home, so I left it where his truck and my hay baler are located, and I will bum a ride down and pull the baler back.

Questions:
1) what would cause it to puke black when I leaned into it leaving the town it was at? probably ran at least 10 minutes and was half warmed up. vane position sensor, turbo issues, etc? what exactly controls the vanes on these?

2) how much fun is it to dis-assemble the cooling stack on these? combination of crap in stack, and t-stats, she did get up near 210 running empty, and would float around. ran really cold first 10 miles, then started coming up, nearly hit 210, then back down.

Looks like original fill Dex-Cool. plan on draining and putting fresh in. I assume get t-stats from the dealer, and nowhere else? (or does Rock auto sell the correct OEM ones?)

I am pretty impressed with the ol ZF6, shifts quick, and I easily got the hang of the double detent and left slot reverse. I think the truck loves me.

I topped it off and put half a bottle in each tank of Stanadyne lubricity formula.

Power steering fluid looks gross, need to flush and install the factory cooler, cant believe they dont come with one.

 

[WarWagon]

As much as I neglect to say air filter...

Pouring out the black starting out on Duramax engines equipped with EGR is sometimes a bad EGR flopping wide open when it shouldn't. Other notable symptom with this is the black clears up with RPM and you take off.

High back pressure is known to blow open even a good EGR. So clogged or melted cat, collapsed exhaust, etc are also something to check.

LLY running hot already?

 

[JayTheCPA]

1) what would cause it to puke black when I leaned into it leaving the town it was at? probably ran at least 10 minutes and was half warmed up.
. . .
Power steering fluid looks gross, need to flush and install the factory cooler, cant believe they dont come with one.

Did it belch once-and-done, or repeatedly? If once-and-done, could have had excessive idling in recent history.

And if the power steering fluid looks that bad, chances are that all the other lubes need replacing too.

 

[btfarm]

Did it belch once-and-done, or repeatedly? If once-and-done, could have had excessive idling in recent history.

Agreed. With a working EGR, PCV, and cat these tend to blow out alot of built up soot when you first hit it after alot of idling and low speed driving. If it didn't clear then that's a different thing.

 

[THEFERMANATOR]

Really starting to hate my local Allison shop. stopped in today, asked about why they were closed on Sat. "Oh, well, Saturdays are pretty hit or miss some days, and the other parts person was gone that day, so we didnt open." What I wanted to say and did not: "Saturdays would be alot more hit and alot less miss if you would actually stay open according to your hours.

Also, same idiot says the 40 dollar per gallon Mobil ATF "is actually Transynd, as Mobil bought the rights" yeah right buddy. Did not buy a damn thing there.

Mobil delvac is transynd. They paid Castrol for the rights so they could sell it through NAPA. The Transynd from allison shouldn't be but $28-30 a gallon.

 

[THEFERMANATOR]

Egr vslves don't normally push open until boist goes past 18-20 as it takes about 50 psi or so of pressure to push one open. 1st thing is find out if its stock tuning or not. Air filters are rarely a concern with the 06+ as they flow so much air. As to the temp, was this on the stock gauge or a scanner? The stock gaugecan read anywhere from 195-210 with engine temps of 170-225. Oem/ac delco or mishimoto is the only ones to run. Thecooling stack isn't bad to clean, but it is a pain to get the inner fan shroud out.

And for the love of Christ, IT'S NOT AN LLY! It's a derated version that for some RIDICULOUS reason GM gave the LLY VIN code to. There is NO part of an 06 that are shared with an 04-05 LLY except for maintence items.

 

[Ed HD]

I was going to say, first thing I'd do is get it home, give it the once-over with new fluids and filters, wash and blow out the radiator stack and take it out for a drive and get on it a little bit, and get a feel for it.

 

[GM Guy]

luckily the smoke was one and done. I have not leaned into it that hard again though, had a piece of farm equipment behind me today.

Got it home!

Fuel guage has not even come off full. Ah, the joys of loping along in 5th at 1900 RPM...

I think I might have figured out some of the clutch issues some guys (not me luckily) have with ZF6 clutches.

Right in the Duramax supplement, it says the 5 speeds run DOT3 brake fluid in the clutch, ZF6 runs DOT4. I wonder what I have... God only knows who put what in there...


How hard is it to dis-assemble the stack, and what do I leave in and what do I take out when I clean it?

Finally, with my HVAC issues, not only is the blower inop, but so is the temperature control. What is the usual failure in this part? Control head or actuators?

 

[JayTheCPA]

luckily the smoke was one and done. I have not leaned into it that hard again though, had a piece of farm equipment behind me today.

Actually, that was a good time to lean into it and see if the cloud was just from built-up crud. With the load, it would have had an extended time to get good torque and heat through the motor

I have found that 3'rd (actually 4'th if you count the creeper) is a good gear for blowing out the 'stuff'. Start out around 25 mph in 3'rd, lean into it, and let the motor go through the RPM band as far as the speed limit / comfort factor allows. After one (maybe two) of those and it should not have any idle related crud left.

 

[THEFERMANATOR]

The only difference between dot 3 and dot 4 is the temperature rating. Dot 4 is a higher temp fluid designed to work with abs systems and 4 wheel disc brakes, and is backwards compatible with dot 3. They're both aqueous fluids that should be flushed out and changed every 5 years or so.

As to the control head, which one is it? Theres 3 different styles of a/c's in these trucks. Manual temp control, dual zone temp control, and automatic climate control. Actuators and blower resistor/controllers are known for issues just like every other GM product is known for.

As to the cooling stack, I would pull the fan shrouds, replace the fan clutch while you're in there, remove the radiator, and then the intercooler. It isn't that hard to get them apart to clean really, and on a ranch truck I would do it all.

 

[WarWagon]

luckily the smoke was one and done. I have not leaned into it that hard again though, had a piece of farm equipment behind me today.

Got it home!

Fuel guage has not even come off full. Ah, the joys of loping along in 5th at 1900 RPM...

I think I might have figured out some of the clutch issues some guys (not me luckily) have with ZF6 clutches.

Right in the Duramax supplement, it says the 5 speeds run DOT3 brake fluid in the clutch, ZF6 runs DOT4. I wonder what I have... God only knows who put what in there...


How hard is it to dis-assemble the stack, and what do I leave in and what do I take out when I clean it?

Finally, with my HVAC issues, not only is the blower inop, but so is the temperature control. What is the usual failure in this part? Control head or actuators?

Like many GM models of this vintage: The HVAC plug at the resistor pack burns up requiring a new connector and resistor pack. There is actually a Special Policy Coverage Adjustment on it.

Subject: 10240 - Special Coverage Adjustment - Heating, Ventilation, and Air Conditioning Blower Not Fully Functional or Inoperative


Models: 2003-2006 Chevrolet Avalanche, Suburban Tahoe

2003-2007 Chevrolet Silverado

2003-2006 GMC Yukon, Yukon XL

2003-2007 GMC Sierra

Equipped with Manual HVAC (CJ3) or Heavy Duty Heater (C42)


--------------------------------------------------------------------------------

Condition
On some 2003-2006 model year Chevrolet Avalanche, Suburban, Tahoe; GMC Yukon, Yukon XL; and 2003-2007 model year Chevrolet Silverado and GMC Sierra vehicles equipped with a manual heating, ventilation, and air conditioning (HVAC) system (CJ3) or heavy duty heater (C42), the interface between the electrical terminals of the relay resistor module and the wiring connector that powers the module may be incapable of conducting higher current levels for sustained periods of blower motor operation. In addition, moisture and other contaminants may enter the fresh air intake plenum and contact the internal circuit of the module or corrode the terminals. If any of these were to occur, the relay resistor module or wiring connector could overheat and the HVAC blower may not function on certain blower settings or may be inoperative. This may be accompanied by a burning smell or smoke.

Special Policy Coverage Adjustment
This special coverage covers the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

Dealers are to install a new blower motor resistor and resistor module connector. The repairs will be made at no charge to the customer.

 

[THEFERMANATOR]

Like many GM models of this vintage: The HVAC plug at the resistor pack burns up requiring a new connector and resistor pack. There is actually a Special Policy Coverage Adjustment on it.

Subject: 10240 - Special Coverage Adjustment - Heating, Ventilation, and Air Conditioning Blower Not Fully Functional or Inoperative


Models: 2003-2006 Chevrolet Avalanche, Suburban Tahoe

2003-2007 Chevrolet Silverado

2003-2006 GMC Yukon, Yukon XL

2003-2007 GMC Sierra

Equipped with Manual HVAC (CJ3) or Heavy Duty Heater (C42)


--------------------------------------------------------------------------------

Condition
On some 2003-2006 model year Chevrolet Avalanche, Suburban, Tahoe; GMC Yukon, Yukon XL; and 2003-2007 model year Chevrolet Silverado and GMC Sierra vehicles equipped with a manual heating, ventilation, and air conditioning (HVAC) system (CJ3) or heavy duty heater (C42), the interface between the electrical terminals of the relay resistor module and the wiring connector that powers the module may be incapable of conducting higher current levels for sustained periods of blower motor operation. In addition, moisture and other contaminants may enter the fresh air intake plenum and contact the internal circuit of the module or corrode the terminals. If any of these were to occur, the relay resistor module or wiring connector could overheat and the HVAC blower may not function on certain blower settings or may be inoperative. This may be accompanied by a burning smell or smoke.

Special Policy Coverage Adjustment
This special coverage covers the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.

Dealers are to install a new blower motor resistor and resistor module connector. The repairs will be made at no charge to the customer.

This is if it has the dual zone manual climate control, thats why I asked what he has. Without knowing, it's all guesses.

 

[Ed HD]

Looks like the Dual-Manual.

 

[btfarm]

I'd suggest that you do what I did after you get that inner fan shroud out. Hang it on the wall permanently as a conversation piece

 

[THEFERMANATOR]

The resistor and plug is a known issue with them, and so are the actuators for the temp doors.

 

[GM Guy]

Sorry guys, I thought I had mentioned earlier I had found the TSB on the blower motor issues earlier, It definitely has the full list, that is for sure.

The special coverage on this one ran out back in september and 4,000 miles ago, but our local GM dealer says that GM is decent about still chipping in on things like this.

I imagine off warranty i am looking at quite a bill, so hopefully they will float most of it.

 

[THEFERMANATOR]

It's less than a $100 for the new resistor and plug last time I bought one.

 

[GM Guy]

can they find out which blend door is messing up with the tech II? It wont change temp also, constant heat. does not seem to matter which side.

I can punch the a/c button and get it to blink, so I think the system is getting juice properly.

 

[THEFERMANATOR]

Are both sides on heat? I know the drivers side temp actuator is located on the front of the hvac box directly over the trans tunnel.

 

[GM Guy]

GM OE only for t-stats I assume? OK to get through rockauto as long as I choose the ones labeled Original Equipment?

I remember Ferm mentioning keeping the a/c compressor where its at for fear of leaks and pull it apart as she sits.

Is there any preference on coolant filter kits? I want a nice bolt on one.

IMO Cat EC1 is the best, but how bad is Dex? should I switch to EC1, or keep the Dex? I know 01-02 had issues with gasket material, I assume LBZ had this fixed?