o.t. duramax questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

browndawg71 · 07-11-2004, 11:04 PM

i have been considering a new chevy with the duramax diesel and would appreciate any feedback from any owners or possibly GM mechanics . what kind of fuel mileage and any prolems if any.

griesel72 · 07-11-2004, 11:43 PM

I get about 18 mpg with mine (3/4 ton, 4X4 extended cab) I've had some problems with the brake system, but the truck runs/pulls really nice.

Good luck

David

browndawg71 · 07-12-2004, 12:09 AM

griesel72 what kind of brake problems and what trans are you running. i have drove a friends and was very impressed with the performance and he loves it .i have heard alot of good things about them.

Shane65 · 07-12-2004, 08:46 AM

If you are considering a used one, check out the price of rotors for the truck before you buy. I had a mechanic tell me of a guy that had to have all four replaced at at price of(are you sitting down?) over $1700 each(Canadian). Add in the price of calipers, pads and labour. That's one hell of a shock to the wallet. Now if we were talking of an exotic Ferrari or something, the price may be sane but this is a truck!

griesel72 · 07-12-2004, 06:18 PM

browndawg71

my truck has the allison automatic, which is pretty impressive with it's ability to shift down and slow the truck with out even pushing the brake.

My truck has what was referred to by the chevy mechanics as a "phantom" problem. when i picked up the truck the first time, right after i started it, it came on with a message "service brake system" I had them take it back to the shop, and they told me that they fixed the problem, but every once in a while it comes on with the same message, but no chevy dealership seems to be able to fix it. It doesn't seem to affect the brakes, but it scares a guy to have a possible problem with the brakes on a 40000 dollar truck.

If you're looking at a 2001, i know that Teeitup just bought a 2001 with almost 90000 miles, and is having good luck (as far as i know)

Good luck, i know you will like it.

David

T HAUS · 07-12-2004, 06:35 PM

I've got an '03 and we just turned 20k. We've got a 3/4 ton, full 4 door, 4x4, with the Allison.

No problems other than some board burned up within the 1st 1000 miles and it would not allow the air to work on the driver's side. Just blazing heat and the blower blowing full speed.

Also had a faulty brake sensor go out. Would not allow the cruise to work.

Other than that, it's a great truck. I live in SW Mo, and we drove it to Florida and Colorado last yr. Avg mpg around 19 on the hwy at 70mph.

I've had an 01 Dodge and I love the Cummins, but Dodge cannot keep a tranny behind the Cummins IMO.

teeitup · 07-12-2004, 07:55 PM

Yes I bought a 2001 3/4 4x4 ext cab about three or four months ago just turned over 100K on it, I've put 8K on it since I bought it. No problems yet, getting 15-16 mpg. Allison tranny is AWESOME so far!!!!!

Tx Firefighter · 07-12-2004, 11:14 PM

Just make sure you get the "LLY" engine if you get a 2004 model. That is the newer version that has lots of changes to it, namely much better injectors.

It was a running change in the model year.

They're typical GM trucks, that is to say, they are plush and real nice overall. The aluminum heads scare me a little though.

Hijack to respond to post above- By the way, the Cummins has the heaviest duty transmission available. Both mine and my wife's Cummins trucks have the NV5600 6 speed manuals. No tougher transmission in a diesel truck ever.

As far as Dodge auto trans go, notice both of mine are 6 speed manuals? Enough said on that....

I'm a real big hot rod diesel junky. 700 ft/lbs of torque is easy with any of the big three diesel engines nowdays.

breeh · 07-13-2004, 12:08 AM

I have an '04 Crew Cab with the LLY. I have had zero problems so far but only 6k miles. I think that it is just beginning to get broke in as the mileage just keeps getting better (19mpg unloaded). I haul a 3500# Alpenlite truck camper on it and it doesn't even know it is there. Also, I have the Allison trans....

68C15 · 07-13-2004, 07:27 AM

Tx Firefighter, with simple plugin reprogammer they can get over 900 ft lbs. although you need to strengthen the flexplate lugs on converter as they will shear off. imagine 12.9 in the 1/4!!!
the new ones with the improved injectors I havent worked on yet but the only problem I have seen with the older ones is injectors getting plugged with dirty fuel. at a cost of about $500 each just for parts. you have nothing to worry about with the heads. I had the heads off one that had over 200K miles & there was NO RING RIDGE. even still had the crosshatch on cyl walls!! some of them had a small crack in the fuel rail pressure regulator. keep in mind they run @ 30K PSI so DO NOT OPEN LINES WHILE RUNNING.
to sum it all up if I was in the market for a diesel I wouldnt get anything else than a Dmax-Allison
truck -GM engine-Isuzu fuel injection-Bosch
PS the reason the heads came off is somewhat embarrasing (lack of info & other shop incorrectly replacing an injector)

07-11-2004, 11:04 PM	#1
browndawg71 Registered User Join Date: Jun 2004 Location: paris, texas Posts: 235	o.t. duramax questions i have been considering a new chevy with the duramax diesel and would appreciate any feedback from any owners or possibly GM mechanics . what kind of fuel mileage and any prolems if any.

07-11-2004, 11:43 PM	#2
griesel72 Senior Member Join Date: Apr 2003 Location: Howard, Kansas USA Posts: 1,997	I get about 18 mpg with mine (3/4 ton, 4X4 extended cab) I've had some problems with the brake system, but the truck runs/pulls really nice. Good luck David __________________ 1969 K10 Custom 10 1997 Z71 2006 Volkswagen Jetta TDI 2006 King Ranch 1980 Wife

07-12-2004, 08:46 AM	#4
Shane65 Registered User Join Date: Oct 2003 Location: Ontario Posts: 108	If you are considering a used one, check out the price of rotors for the truck before you buy. I had a mechanic tell me of a guy that had to have all four replaced at at price of(are you sitting down?) over $1700 each(Canadian). Add in the price of calipers, pads and labour. That's one hell of a shock to the wallet. Now if we were talking of an exotic Ferrari or something, the price may be sane but this is a truck! Last edited by Shane65; 07-12-2004 at 08:48 AM.

07-12-2004, 06:18 PM	#5
griesel72 Senior Member Join Date: Apr 2003 Location: Howard, Kansas USA Posts: 1,997	browndawg71 my truck has the allison automatic, which is pretty impressive with it's ability to shift down and slow the truck with out even pushing the brake. My truck has what was referred to by the chevy mechanics as a "phantom" problem. when i picked up the truck the first time, right after i started it, it came on with a message "service brake system" I had them take it back to the shop, and they told me that they fixed the problem, but every once in a while it comes on with the same message, but no chevy dealership seems to be able to fix it. It doesn't seem to affect the brakes, but it scares a guy to have a possible problem with the brakes on a 40000 dollar truck. If you're looking at a 2001, i know that Teeitup just bought a 2001 with almost 90000 miles, and is having good luck (as far as i know) Good luck, i know you will like it. David __________________ 1969 K10 Custom 10 1997 Z71 2006 Volkswagen Jetta TDI 2006 King Ranch 1980 Wife

07-12-2004, 06:35 PM	#6
T HAUS Registered User Join Date: Nov 2003 Location: SW Missouri Posts: 111	I've got an '03 and we just turned 20k. We've got a 3/4 ton, full 4 door, 4x4, with the Allison. No problems other than some board burned up within the 1st 1000 miles and it would not allow the air to work on the driver's side. Just blazing heat and the blower blowing full speed. Also had a faulty brake sensor go out. Would not allow the cruise to work. Other than that, it's a great truck. I live in SW Mo, and we drove it to Florida and Colorado last yr. Avg mpg around 19 on the hwy at 70mph. I've had an 01 Dodge and I love the Cummins, but Dodge cannot keep a tranny behind the Cummins IMO. __________________ 1966 Chevy C-10 1970 Chevy K-5 Blazer 4x4 1972 Chevy K-5 Blazer 4x4 2003 2500HD GMC Duramax/Allison 4x4 Full 4 Door

07-12-2004, 12:09 AM	#3
browndawg71 Registered User Join Date: Jun 2004 Location: paris, texas Posts: 235	griesel72 what kind of brake problems and what trans are you running. i have drove a friends and was very impressed with the performance and he loves it .i have heard alot of good things about them.

07-12-2004, 07:55 PM	#7
teeitup Just like to part out trucks!! Join Date: Nov 2001 Location: Meriden, Ks-North of Topeka 10 miles Posts: 27,395	Yes I bought a 2001 3/4 4x4 ext cab about three or four months ago just turned over 100K on it, I've put 8K on it since I bought it. No problems yet, getting 15-16 mpg. Allison tranny is AWESOME so far!!!!! __________________ 67 Chev swb stepside 4x4 283 4 speed SOLD 72 blazer 4x4 4 speed Cheyenne 72 GMC swb 4x4 fleet 4 speed, original paint 1958 Cameo (one of 1405 built, it was my dads) 2020 chevy Apex 4x4 crew cab 1969 Z28 with the 302 1980 chevy swb 4x4 1964 chevell Malibu SS 1976 K20, sold new originally out of my dads chevy dealership Members that I've met, over 200 probably closer to 300 in the 12 years I've been on this site, everyone I met "It was a pleasure"

07-12-2004, 11:14 PM	#8
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Just make sure you get the "LLY" engine if you get a 2004 model. That is the newer version that has lots of changes to it, namely much better injectors. It was a running change in the model year. They're typical GM trucks, that is to say, they are plush and real nice overall. The aluminum heads scare me a little though. Hijack to respond to post above- By the way, the Cummins has the heaviest duty transmission available. Both mine and my wife's Cummins trucks have the NV5600 6 speed manuals. No tougher transmission in a diesel truck ever. As far as Dodge auto trans go, notice both of mine are 6 speed manuals? Enough said on that.... I'm a real big hot rod diesel junky. 700 ft/lbs of torque is easy with any of the big three diesel engines nowdays. __________________ I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 07-12-2004 at 11:17 PM.

07-13-2004, 12:08 AM	#9
breeh Recovering 67-72 Addict Join Date: Oct 2000 Location: North Bend, WA Posts: 1,788	I have an '04 Crew Cab with the LLY. I have had zero problems so far but only 6k miles. I think that it is just beginning to get broke in as the mileage just keeps getting better (19mpg unloaded). I haul a 3500# Alpenlite truck camper on it and it doesn't even know it is there. Also, I have the Allison trans.... __________________ 68 Short Fleet 4x4; 427; BTO Level 3 700R4; NP205; Dana 60 front and rear; 4" lift with 35's; Disc brakes; AGR variable ratio steering; factory bucket seats; factory tach and tilt. "Friends call me cruzer cuz I like fast cars and fast women"

07-13-2004, 07:27 AM	#10
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Tx Firefighter, with simple plugin reprogammer they can get over 900 ft lbs. although you need to strengthen the flexplate lugs on converter as they will shear off. imagine 12.9 in the 1/4!!! the new ones with the improved injectors I havent worked on yet but the only problem I have seen with the older ones is injectors getting plugged with dirty fuel. at a cost of about $500 each just for parts. you have nothing to worry about with the heads. I had the heads off one that had over 200K miles & there was NO RING RIDGE. even still had the crosshatch on cyl walls!! some of them had a small crack in the fuel rail pressure regulator. keep in mind they run @ 30K PSI so DO NOT OPEN LINES WHILE RUNNING. to sum it all up if I was in the market for a diesel I wouldnt get anything else than a Dmax-Allison truck -GM engine-Isuzu fuel injection-Bosch PS the reason the heads came off is somewhat embarrasing (lack of info & other shop incorrectly replacing an injector) __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card



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