I have what sounds like noisy lifters when I acclerate. I brought it to the dealer, and they confirmed it. They advised against trying to adjust because its a very time consuming job and they may not fix it.
Has anyone else experienced this? Is the dealer full of it? The truck is still under warranty.

I'd run a balance check on the injectors.There is NO lifter adjustment that I'm aware of and that's the first I've heard of.

Sounds like noisy injectors to me

I actually had all 8 injectors replaced less than 10,000 miles ago. Could they be failing again?

Yes there is a valve lash adjustment. It is .012.I personally adjust valve lash on all injector jobs. They are always loose. It makes them so much Quieter. It is alot of work but if it is Really noisey you probablly should have it done.If not horrible I would wait till you need injectors. Have balance rates checked and regulator return rate. Tim

With a 100k engine warranty wouldn't that be warranty work? Of course with a $100 deductible it might not be worth it. Anybody know the flat rate time for a valve adjustment?

Seems to me it should have been done when the injectors were changed.:ro)

Midwest
Its not horribly loud, just enough where I can hear it. My injectors were replaced less than 10,000 miles ago. Should the dealer have adjusted them at that point regardless of whether it was an issue or not?

Once again this finding a good and reliable tech. Should it have been done? yes is it required? no Because it is such a big job it takes only 1/2 hour once your there. Of course the argument is going to be --you can barely do injectors in the time GM pays I'm not adjusting lash too. I do, it all goes to a much quieter and overall customer satisfation.

Midwest
Thank you for your input, I apreciate it.

Yes there is a valve lash adjustment. It is .012.I personally adjust valve lash on all injector jobs. They are always loose. It makes them so much Quieter. It is alot of work but if it is Really noisey you probablly should have it done.If not horrible I would wait till you need injectors. Have balance rates checked and regulator return rate. Tim

Interesting

Is it a actual adjustment or tolerance?

Mackin, I know you're asking Midwest, but I'm certain I saw adjustment nuts on the rocker arms of the 2 or 3 DMaxs I've seen with the val;ve covers off.

You get some different coefficient of expansion with the iron block and the alum heads. Unsure of the effect, but if the manual says .012 clearance, then I guess then that's what they should be adjusted to. And seems to me any mechanic that really cared about his work would at least try to get the service manager to OK half an hr or so tacked on for this adjustment.
I don't work on vehicles for a profession, but if I have the valve covers off one of my own, and it has an adjustable valve train, I check lash or hydraulic preload, as the case may be.
Are the lifters on DMax hydraulic or solid?

Getting GM to pay for a lash adjustment is unlikely IMO, but like midwest says, a good tech may do it, ( I never have and never found a reason to even check) but I may check the next couple I have down and see how they are and how close they are.

Ditto to what Dmaxali said.... I'm sure the rest of you would go beyond the call of duty while you're making a living as a dealer tech with no additional compensation
:blahblah: . I will for my own learning experience check the next couple I do as well. I'm not opposed to learning.:)

The lifters are solid therfore IMO it should be checked especially with the valve covers off.They are usually .015 or better. In some instances when there is valve/seat wear the valve receeds in the head narrowing the clearance.Too tight lash can burn valves and cause a slight hp loss @ high rpm. The adjuster is a screwdriver slot with a 14mm jamb nut on the rocker arm over the pushrod.
Valve lash can be done with just the primary/upper valve cover off so not quite as much work as injectors.

Duramax cam is a roller design - solid roller lifters

ok, now i'm confused. i was never aware of need=ing valve adjustments. I've got 148k on the ole girl and i'd swear i have a valve tap, but i've only heard about the "dreaded tick" and "noisy injectors". i've been under the impression the lifters were hydraulic. In light of this new revalation, how can i figure out which noise i have. my tap never goes away, increases rythmacally with rpm, ie, the faster the revs, the noisier one valve, (or injector, or something) gets. temp of engine also doesn't matter. same tap all the time. i've always thought it was a valve tap but have been convinced otherwise.
so how big of a job is it to adjust the valves--i believe it is the left bank. i've done inj balance rates several times and they are always fine, well within range. truck runs great, no issues other than tap, tap ,tap,tap.
sorry for the long post but this is very interesting to me--i just did a search for valve lash adjustment and valve adjustment and in this forum i found only this single post with the info that there is valve lash adjustment "required".
great site.:rant:

It is not considered maintanance(sp).It is just a very good idea in my opinion. I have done 30-40 sets of injectors and all appear out of spec.(.012) usually loose but some tight.Any other vehicle with solid lifters you would adjust why not this one. I was probably never mandated because of the cost.I'm not shure the labor I wiil try to post tomorrow.

If your noise is an injector, it can be disabled with a scan tool and see if the noise changes. Tim

midwest-
i'll be looking forward to the post. all along i've been waiting for a injector to crap out so i'd get new ones to solve this tapping mystery, but if in fact it is a loose tappet, i can adjust it up and get peace and quiet.
gonna get my stethoscope out today and try again to pin down the cylinder. don't have the proper scan tool to shut down cylinders and the morons in the 2 local gm stores here would like to replace the door hinges to solve the tapping issue:lol:

Midwest, is the .012 lash setting a hot idling setting or a cold setting with engine shut off or what?

Engine off , TDC #1 compression you adjust 5 one side 3 the other. Then rotate 360* and adjust the left over 5 on one side and 3 on the other. Sorry not going into The whole proceedure. The engine should be cool.It will most likelly be cool by the time you get the valve covers off if it is your first time.Labor is 8-9 hours flat rate.

midwest,
what is the firing order?

Firing order is 1 2 7 8 4 5 6 3 And the Rh bank is 1357 LH is 2468.

Firing order 1 2 7 8 4 5 6 3 Rh bank 1,3,5,7 LH 2,4,6,8

Midwest, THX for the info, and I don't need the whole procedure, I've been doing my own maintenance and repair work for 51 years that I have owned motor vehicles and that includes several with solid lifters and even rollers on some of the dirt track cars that gave me my username (driving tactics). Those radical cams in the race cars idled so fast it was next to impossible to adjust hot and running! Good to hear it's a cold, dead engine on the DMax!
A Harley actually increases lash when hot due to the aluminun cylinder, etc expanding more than the steel pushrods, etc. Wonder which wat a DMax goes?

Ok I got a question on this?
If they are I doing the injectors is it easy to do the valve lash check and adjustment or is it a totaly seprate beast?

My wife dropped the Cowboy Caddy off today (injectors and FPR) It was loud as heck, sounds like a 90's PS so I asked her to ask the tech about the valve lash "if they were going to check it" while they were digging around in there repalcing injsectors. She was told today by both service guys ( I think one is the manager) the Dmax's valves are not adjustable. She just looked at him like he was stupid cause I talked to her this morning about this post...she didn't want to get into it since she wasn't clear on the details....and they also let her have a loaner!
I hope it is a case of not knowing the product:badidea: and not a case of thinking she's a gurl and would never know the difference?

I would have rather had him say we will check and adjust if need be and charge you for the time instead of what was said.....

I'm taking a copy of the post down when I pick it up ( I think they hate that:muahaha: ) and see what he says to me..Just for S & G's

Thats the problem, Most guys working on these trucks are just parts replacers.Valve lash is adjustable and is in Service information if they would look. If they won't do it under waranty, let them charge you an hour thats all it should take with valve covers off. Tim

My truck is in the shop as we speak.

My wife called ( I am at work in Seattle it's at home and can't call long distance) and asked Ron the (Diesel) Service Manager while they were in there to go ahead and check and adjust the Lash, Ron the Service Manager said that it is a waste of time and my money they are HYDRAULIC and they will never need to be adjusted for the life of the truck!

She doesn't want to fight with him about it and told me to deal with it......

Here is the info on specs listing mechanical lifters from the GM site...WOW what do you know.....

I do have to say they have been pretty nice out at Parkland Chevy in Tacoma so I can't be too pissed off...they just called her and told her they have to order a couple cooler lines (under warranty) they will have it ready tomorrow afternoon?

I am going to drop this info off for Ron to read ion the ****ter when he gets in in the morning and maybe he won't be so fast to write off a customers request, cause I am sure it wasn't that she's a gurl and doesn't know anything or a straight out lie because he diodn't want his tech doing it......I will give them the benifet of the doubt on it and believe it was a simple misunderstanding of the 6600 Duramax!

Too bad I get home after he has already left for the day...I have friday off so I will be going in if they don't get it done Thursady and the wife pics it up......

Ok on further review do the LB7's have mechanical or hydrualic lifters

It looks like the LLY's have mechanical and LB7's which mine is have Hydraulic......

Looks like I got CROW to eat........thanks!

WHAT!!!!! Who give you that crap?They have SOLID roller lifters and have not changed on the LLY.If they're not solid why is there a spec (.012)These dealers that blow crap up peoples butts when the info is right there to read P-ss me off.I guess the 50+ I've done were wrong. Tell them to adjust them anyway just for the h-ll of it.

MIDWEST,
Hey man my apologies, I was told they are hydra from the diesel service manager and when looking up specs from GM's sight I only found LLY's and they do list them as Mechanical, so I went searching, searching LB7 lifters I found a bunch of stuff that said Hydra for the lifters? It was late and I was headed out the door so when I got home I dug and dug and found the answer on specs of the LB7 on a couple of GM related sites.......

They didn't have it completed yesterday so I didn't go talk to RON the service manager but I will be going there tomorrow since I have the day off.......I have copied all this stuff and just hope they don't do this to anyone else, I am going to ask that they go in and check and adjust if need be on there dime since he was at fault and it was asked (even with me paying for it)...... I doubt it will happen but since the service deopartment screwed up maybe they will waive the 100 deductable for a couple other warranty items they did?

Anyway Thanks you so much Midwest, you are a wealth of knowledge and all I can say is thanks!
JOSH

I was not po'd at you. I thought someone was blowing smoke up your a--. I want the best for you and all dmax owners. Checking valve lash is a great improvement for overall customer satisfaction.Tell the dealer it is document #808020 if they would just look. Tim