Chevy/GMC Duramax

[BillTex]

Originally Posted by r carl

Kinda long but interesting.
Chevy Silverado HD2HD | Pickup Truck Comparison | Chevrolet.com

That was interesting...the payload tests show some real differences in chassis engineering. No wonder the GM capacity numbers are up for the new design.

Really, you can't go wrong with any of the new HD trucks...although if looking at Ford...I would wait a few years for the new drive train to be proven.
GM, and of course, Cummins are well tested at this point.

If you need to be the first up the hill...buy a GM!

Happy New Year!

Bill

[moosetags]

Fred, the truck, is our 2011 Chevrolet Silverado 3500 Duramax 4x4. Fred is a crew cab long bed with single rear wheels.

We took delivery of Fred on August 5th of this year. Fred is our first diesel tow vehicle. Before Fred, we always pulled Lucy with 3/4 ton Suburbans. We bought Fred so that we would be able to carry our new Outfitter truck camper and tow the Airstream at the same time.

We now have a little over 15,000 miles on the new truck. We couldn't be more pleased with Fred's capabilities and road manners. We haven't weighed the truck camper yet, but are estimating that we are somewhere around 2200# ready to camp. Lucy weighs in at 7400# with an 850# tongue weight.

After 15,000 miles, most of it towing Lucy with the truck camper on board, we are convinced that we got the right vehicle for the job. Fred rarely has to down shift on an upgrade at highway speeds. He just reaches down into his bag of torque and continues on. Fred's engine braking system handles the down hill duties with confidence. We no longer experience any of the runaway train feelings that we would sometimes get towing the Airstream down hill with the Suburbans.

Fred's road handling capabilities are excellent, both on the highway solo or towing, and off road in the back country with the truck camper.

Brian

[gsmithii]

All,

Our '06 Chev is now running it's "new" reman engine after the original was brutally killed. Bulletproof can't survive "I think you have an electrical problem" for that low oil pressure indicaton.

When we last met we had just enjoyed a ride off the mountain from Skyline Drive to Charlottesville and we were waiting for a decision by GM on whether they would replace our engine. GM did replace the engine - actually the GM Protection Plan insurance policy we bought when we bought the truck two years ago. That was a huge relief to say the least.

Of course with a pretty new engine in a slightly used non-DEF truck we are planning to drive this beauty for a right good long time. Our Safari follows the truck like a little puppy dog & the truck barely knows it's there.

[moosetags]

I read that you are saying that Chevrolet replaced you engine with a pre LML/DEF motor. Is that correrst?

Brian

[gsmithii]

Originally Posted by moosetags

I read that you are saying that Chevrolet replaced you engine with a pre LML/DEF motor. Is that correrst?

Brian

Brian,

Yes, they did.

Supposedly the remanufactured engine is an identical replacement for the original engine. No DEF or any need to consider the new emissions requirements. It should be an LBZ engine from top to bottom.

As was written elsewhere, including this thread, that could be a mixed deal with all the strengths and weaknesses of that engine.

All things considered as I wrote previously, if the engine is "new" the cost/benefit equation works out to run this truck until it croaks. I may go before it does.

[dznf0g]

Emissions requirements apply to the build date of the VIN on the truck, not a parts replacement date.

[Streamside]

I have seriously looked into replacing my 02 gmc oil burner (with either a ford or gm) since reaching 200k miles but have a question for those of you that have 2011or 2012 models that have the regen to burn off the soot. Do your fuel milage computers account for the fuel burn during the regen? Has anyone done enough fuel receipt collection over an extended period of travel to verify the computer. It is great that some people are reporting such great milage figures but it seems to conflict with other reports on the diesel forums that I have visited.

Not to be disrespectful so I am posting this same question on the F250 thread, too.

[dznf0g]

Originally Posted by Streamside

I have seriously looked into replacing my 02 gmc oil burner (with either a ford or gm) since reaching 200k miles but have a question for those of you that have 2011or 2012 models that have the regen to burn off the soot. Do your fuel milage computers account for the fuel burn during the regen? Has anyone done enough fuel receipt collection over an extended period of travel to verify the computer. It is great that some people are reporting such great milage figures but it seems to conflict with other reports on the diesel forums that I have visited.

Not to be disrespectful so I am posting this same question on the F250 thread, too.

GMs do account for all fuel usage. The calculation is performed with all the fuel delivery commanded by the powertrain control module. A lot of folks here don't believe their onboard system is as accurate as pencil and paper and the variables between multiple station pumps, so you're probably going to get some disagreement here.

[Streamside]

Originally Posted by dznf0g

GMs do account for all fuel usage. The calculation is performed with all the fuel delivery commanded by the powertrain control module. A lot of folks here don't believe their onboard system is as accurate as pencil and paper and the variables between multiple station pumps, so you're probably going to get some disagreement here.

I was hoping that was the answer.

[moosetags]

We have a 2011 Chevrolet Silverado 3500 Duramax. We took delivery on August 5, 2011. It was one of the last 2011's made. It now has 16,000 miles on it. I have closely monitored fuel consumption from the beginning, both manually and with the on-board computer. I have found the on-board computer to be extremely accurate. I now depend on it solely.

Thus far, the fuel mileage has been roughly what I expected. The truck alone has gotten 18 mpg on the highway. Pulling the Airstream with the solo truck gets 13 mpg. With the Outfitter truck camper solo, it gets 14 mpg. Pulling the Airstream with the Outfitter on board, the truck gets 11 mpg.

The truck has been consuming approximately 2.5 gallons of DEF every 2,500 miles.

I had the truck at a Chevrolet in Scranton, Pennsylvania, for a DEF system warning message. It turns out that I had turned the truck off during a regen which resulted in this warning the next morning. I did find out from the technician that the truck had under gone 10 regens with 10,000 miles on it. This would indicate that a regen takes place roughly every 500 miles with my type of driving. WE do mostly highway driving. Our average speed at 15,000 miles was 45.6 mph.

Brian

[dscluchfc]

I have the 02 GMC Duramax/Allison.
Recently spent close to $9000.00 in repairs.
This is how it went.
At about 200K miles the coolant reservoir began to darken. I didn't think much of it since a mechanic had placed some florescent marker dye in the coolant quite a while before that to trace a coolant leak at the oil cooler feeder tube, and I thought this might be a side effect of the dye.....wrong!
Gummy tarrish stuff began to appear in the coolant tank and the tank gradually turned black. Diagnosis limited to soot or oil in the coolant and it turned out to be oil.
The source of the oil was a cracked housing of the oil cooler where the oil filter screws on....remember that marker dye...the long bolts of the housing were run out and back in with sealant on them which stopped the coolant leak, and had to be periodically redone...but the ROOT CAUSE was a cracked oil cooler housing which began to inject oil at high pressure into the coolant.

The fix was to replace the oil cooler, the upper and lower radiator hoses, remove clean and return the radiator, power flush the block, power flush the heater core, new heater hoses and new coolant reservoir.....$3100.00

The fuel gauge had not worked for a couple of years, so I had the sending unit fuel pump in the tank replaced, $970.00

But, there was still a intermittent white cloud in the exhaust....which now began to get worse. I had done an injector job only 46K miles previously at 186K miles, and so I was NOT happy to be told 4 of the LB7 injectors were bad. GM provided no help because the truck had 232K miles on it, Bosch Injectors provided no help because the injectors had 46K miles on them and they only warrant to 12K, but the dealership agreed to take nearly $2000 off the price of a complete injector job...so we proceeded. Upon delving into this we began to search for possible reasons for the early failure of the injectors.

In the process of doing the injectors and looking for reasons for contamination it was discovered the fuel rails were contaminated with metal...the only place that could come from is the high pressure injection pump which had 232K miles on it., So the injector pump was also replaced. Total cost of 8 new injectors and new injector pump $4700.00.

We were told the OEM filter filters to 7 microns and Bosch says anything 7 microns of larger will damage their injectors. So we explored auxillary fuel filtration systems and decided on one from Nicktane.com which uses the Cat IR-0749 2 micron filter placed in line prior to the OEM filter. Cost $338 installed.

So, about $9000 in repair bills on a truck with 232K miles on it.

While mine was in the shop, I met a man from a nearby town who had his in for a refurbish, his 3rd refurbish at 800K miles...his truck was an 01 GMC Duramax which had a farm life of HARD work.

WHAT I LEARNED:

1) Grease is still cheaper than iron. $9000 in repairs is 1/6th of what I could have traded for a new 2012 Duramax....and after this refurbish, I may get another 200K miles out of this one for $9000 plus fuel and maintenance....pretty cheap miles.

2) Refineries only filter diesel to 40 microns, and after it leaves the refinery, there are multiple points of possible contamination into the fuel, so you MUST filter properly.
"Properly" means to at least 2 microns as anything larger than 7 microns will absolutely shorten the life of today's high pressure injectors that run at highway pressures of in excess of 23,000 psi. Fuel filter need to be changed at a minimum of every 8000 miles, and more often if there is the least hint of a bad load of fuel. FILTERS ARE CHEAPER THAN INJECTORS!!! I was accused by the peeps at GM and Bosch of lack of proper maintenance, but I had records and an extra clean truck which contradicted their assumptions. Because of that the local dealer, who had done the injector job 46k miles earlier gave me a break.
If you are not filtering your diesel to a minimum of 2 microns, START ASAP.

3) I am at 238K miles now, and I have a truck which performs like a new one at 1/6th the price of trading. I guess I will see how far this goes....I am pretty much committed for the next couple of years anyway to get my repair money back in driving.

[slowmover]

David, sorry to see the expense, but appreciate that the per-mile cost over the life of the truck -- both time & miles -- gives it a different appearance.

For others -- and maybe to add some more context -- when lifetime costs are translated into a cents-per-mile representation (over many miles and many years) it isn't as daunting an expense. If I posit that the truck will be in operation for 15-years and 350k miles the benefit, as above, of repairs is obvious.

A crate engine replacement for my truck would be in excess of $16k if done at the dealer (not a comparable cost, per se, but to indicate the upper range of potential repairs). While $9k seems high, so again is the performance of a diesel pickup truck properly-specified and carefully used. I believe we've earlier seen seen very good mpg reports on this truck; I know that we have for the model which tends to be very good.

In other words, $9k in no way cancels the reduced fuel use of a high-mpg turbodiesel pickup truck for many owners. And reinforces the choice made over not only a new truck, but even a used replacement that features more power than necessary (at a higher fuel burn rate) with potentially even higher repair costs.

In an exercise I ran the lifelong predicted fuel costs of mine against an accepted average mpg for the 4WD versions with automatics. In this simple calculation the difference at a fuel price point was $26k. So a $9k repair hurts, but the truck is still on track to do a great deal of work at what is still an economical cpm.

To take this outside the realm of a simple model, I have averaged 22-mpg on my truck (different brand) over the past 35,000-miles. While little of that is towing it should also be appreciated that it is also about one-half in-town miles.

It would be very hard to give up a truck with this balance of fuel economy and power as I think is shown by the repairs and report above.

Thanks for the report.

Good luck

.

[BillTex]

Originally Posted by dscluchfc

I have the 02 GMC Duramax/Allison.
Recently spent close to $9000.00 in repairs.
This is how it went.
...

David...sorry if I lost track...did you buy this truck new?
Just curious...

Bill

[dznf0g]

Originally Posted by dscluchfc

I have the 02 GMC Duramax/Allison.
Recently spent close to $9000.00 in repairs.
This is how it went.
At about 200K miles the coolant reservoir began to darken. I didn't think much of it since a mechanic had placed some florescent marker dye in the coolant quite a while before that to trace a coolant leak at the oil cooler feeder tube, and I thought this might be a side effect of the dye.....wrong!
Gummy tarrish stuff began to appear in the coolant tank and the tank gradually turned black. Diagnosis limited to soot or oil in the coolant and it turned out to be oil.
The source of the oil was a cracked housing of the oil cooler where the oil filter screws on....remember that marker dye...the long bolts of the housing were run out and back in with sealant on them which stopped the coolant leak, and had to be periodically redone...but the ROOT CAUSE was a cracked oil cooler housing which began to inject oil at high pressure into the coolant.

The fix was to replace the oil cooler, the upper and lower radiator hoses, remove clean and return the radiator, power flush the block, power flush the heater core, new heater hoses and new coolant reservoir.....$3100.00

The fuel gauge had not worked for a couple of years, so I had the sending unit fuel pump in the tank replaced, $970.00

But, there was still a intermittent white cloud in the exhaust....which now began to get worse. I had done an injector job only 46K miles previously at 186K miles, and so I was NOT happy to be told 4 of the LB7 injectors were bad. GM provided no help because the truck had 232K miles on it, Bosch Injectors provided no help because the injectors had 46K miles on them and they only warrant to 12K, but the dealership agreed to take nearly $2000 off the price of a complete injector job...so we proceeded. Upon delving into this we began to search for possible reasons for the early failure of the injectors.

In the process of doing the injectors and looking for reasons for contamination it was discovered the fuel rails were contaminated with metal...the only place that could come from is the high pressure injection pump which had 232K miles on it., So the injector pump was also replaced. Total cost of 8 new injectors and new injector pump $4700.00.

We were told the OEM filter filters to 7 microns and Bosch says anything 7 microns of larger will damage their injectors. So we explored auxillary fuel filtration systems and decided on one from Nicktane.com which uses the Cat IR-0749 2 micron filter placed in line prior to the OEM filter. Cost $338 installed.

So, about $9000 in repair bills on a truck with 232K miles on it.

While mine was in the shop, I met a man from a nearby town who had his in for a refurbish, his 3rd refurbish at 800K miles...his truck was an 01 GMC Duramax which had a farm life of HARD work.

WHAT I LEARNED:

1) Grease is still cheaper than iron. $9000 in repairs is 1/6th of what I could have traded for a new 2012 Duramax....and after this refurbish, I may get another 200K miles out of this one for $9000 plus fuel and maintenance....pretty cheap miles.

2) Refineries only filter diesel to 40 microns, and after it leaves the refinery, there are multiple points of possible contamination into the fuel, so you MUST filter properly.
"Properly" means to at least 2 microns as anything larger than 7 microns will absolutely shorten the life of today's high pressure injectors that run at highway pressures of in excess of 23,000 psi. Fuel filter need to be changed at a minimum of every 8000 miles, and more often if there is the least hint of a bad load of fuel. FILTERS ARE CHEAPER THAN INJECTORS!!! I was accused by the peeps at GM and Bosch of lack of proper maintenance, but I had records and an extra clean truck which contradicted their assumptions. Because of that the local dealer, who had done the injector job 46k miles earlier gave me a break.
If you are not filtering your diesel to a minimum of 2 microns, START ASAP.

3) I am at 238K miles now, and I have a truck which performs like a new one at 1/6th the price of trading. I guess I will see how far this goes....I am pretty much committed for the next couple of years anyway to get my repair money back in driving.

Sorry about your ordeal. Hey, you were given bad intel on the filters though. Originally Bosch recommended 10 microns (IIRC). Back in about 2008 or 2009 that recommendation was changed from 10 to 2 microns. All parts stock was purged and 2 microns has been all you can get since that time from a dealer.....aftermarket, you're on your own. I THINK Ford did the same thing about the same time.

The downside of this? Carry and extra filter. One load of dirty fuel and you'll be dead in the water. I guess it's a good thing to catch it though. As you found out those high pressure injection pump will get eaten up with even the smallest of dirt. FYI, a human hair is about 10 microns in diameter......always wondered if that's a fine blonde hair or a black curly hair.....? Once the pump goes, the injectors plug and you can't just rebuilt modern high pressure injectors in a shop environment like the old poppet style.

[Streamside]

Originally Posted by dscluchfc

I have the 02 GMC Duramax/Allison.
Recently spent close to $9000.00 in repairs.
This is how it went.
At about 200K miles the coolant reservoir began to darken. I didn't think much of it since a mechanic had placed some florescent marker dye in the coolant quite a while before that to trace a coolant leak at the oil cooler feeder tube, and I thought this might be a side effect of the dye.....wrong!
Gummy tarrish stuff began to appear in the coolant tank and the tank gradually turned black. Diagnosis limited to soot or oil in the coolant and it turned out to be oil.
The source of the oil was a cracked housing of the oil cooler where the oil filter screws on....remember that marker dye...the long bolts of the housing were run out and back in with sealant on them which stopped the coolant leak, and had to be periodically redone...but the ROOT CAUSE was a cracked oil cooler housing which began to inject oil at high pressure into the coolant.

The fix was to replace the oil cooler, the upper and lower radiator hoses, remove clean and return the radiator, power flush the block, power flush the heater core, new heater hoses and new coolant reservoir.....$3100.00

The fuel gauge had not worked for a couple of years, so I had the sending unit fuel pump in the tank replaced, $970.00

But, there was still a intermittent white cloud in the exhaust....which now began to get worse. I had done an injector job only 46K miles previously at 186K miles, and so I was NOT happy to be told 4 of the LB7 injectors were bad. GM provided no help because the truck had 232K miles on it, Bosch Injectors provided no help because the injectors had 46K miles on them and they only warrant to 12K, but the dealership agreed to take nearly $2000 off the price of a complete injector job...so we proceeded. Upon delving into this we began to search for possible reasons for the early failure of the injectors.

In the process of doing the injectors and looking for reasons for contamination it was discovered the fuel rails were contaminated with metal...the only place that could come from is the high pressure injection pump which had 232K miles on it., So the injector pump was also replaced. Total cost of 8 new injectors and new injector pump $4700.00.

We were told the OEM filter filters to 7 microns and Bosch says anything 7 microns of larger will damage their injectors. So we explored auxillary fuel filtration systems and decided on one from Nicktane.com which uses the Cat IR-0749 2 micron filter placed in line prior to the OEM filter. Cost $338 installed.

So, about $9000 in repair bills on a truck with 232K miles on it.

While mine was in the shop, I met a man from a nearby town who had his in for a refurbish, his 3rd refurbish at 800K miles...his truck was an 01 GMC Duramax which had a farm life of HARD work.

WHAT I LEARNED:

1) Grease is still cheaper than iron. $9000 in repairs is 1/6th of what I could have traded for a new 2012 Duramax....and after this refurbish, I may get another 200K miles out of this one for $9000 plus fuel and maintenance....pretty cheap miles.

2) Refineries only filter diesel to 40 microns, and after it leaves the refinery, there are multiple points of possible contamination into the fuel, so you MUST filter properly.
"Properly" means to at least 2 microns as anything larger than 7 microns will absolutely shorten the life of today's high pressure injectors that run at highway pressures of in excess of 23,000 psi. Fuel filter need to be changed at a minimum of every 8000 miles, and more often if there is the least hint of a bad load of fuel. FILTERS ARE CHEAPER THAN INJECTORS!!! I was accused by the peeps at GM and Bosch of lack of proper maintenance, but I had records and an extra clean truck which contradicted their assumptions. Because of that the local dealer, who had done the injector job 46k miles earlier gave me a break.
If you are not filtering your diesel to a minimum of 2 microns, START ASAP.

3) I am at 238K miles now, and I have a truck which performs like a new one at 1/6th the price of trading. I guess I will see how far this goes....I am pretty much committed for the next couple of years anyway to get my repair money back in driving.

Knowing what you know now and if you had the chance to trade for a 2012, would you have done it or just spent the $$? I've got the same truck, replaced injectors. Water pump, transmission cooling line and lower rad hose... That's all outside of normal maintenance. About 210,000 miles and still runs really good. Have been contemplating the trade before something really happens... $8k for another 5 to 10 years doesn't seem that bad right now!

[dznf0g]

Originally Posted by Streamside

Knowing what you know now and if you had the chance to trade for a 2012, would you have done it or just spent the $$? I've got the same truck, replaced injectors. Water pump, transmission cooling line and lower rad hose... That's all outside of normal maintenance. About 210,000 miles and still runs really good. Have been contemplating the trade before something really happens... $8k for another 5 to 10 years doesn't seem that bad right now!

All I can tell you is I have one fleet account who turns them at 750,000 miles. They seem to think that the durability vs. maintenance/repair costs pencil out to that mileage.

They are a trailer manufacturer with their own dealer delivery trucks. They run pretty much 16 hours a day loaded.

[slowmover]

Originally Posted by dznf0g

All I can tell you is I have one fleet account who turns them at 750,000 miles. They seem to think that the durability vs. maintenance/repair costs pencil out to that mileage.

They are a trailer manufacturer with their own dealer delivery trucks. They run pretty much 16 hours a day loaded.

Any idea of the average mph? Or how many engine hours when they turn them?

Thanks

[dznf0g]

Not for sure, but they are highway miles delivering utility, horse, car, etc trailers....so my guess would be avg. 50 mph over life.....so 15,000 hours or so. I doubt they see much idle time like a pto service truck or a semi, if that's what you mean. That's strictly and educated guess of how that type of fleet is normally run. I never asked these guys specifically.

[slowmover]

Your guess makes sense. I think of these engines as being 10,000-hour capable. Those miles and use then make sense for the outer edge of what is realistic.

Thanks

[r carl]

May be worth checking into.
http://www.powerupdiesel.biz/