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2001 2500HD 6.0 knock

Discussion in '1992-Present Chevy & GMC models' started by roostr3269, Dec 29, 2001.

  1. roostr3269

    roostr3269 1/2 ton status

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    I bought my silverado last winter and at around 6000 miles I started hearing a knock. I called the dealer and they told me to bring it in. I was told that its a condition called piston slap and it wont affect the reliability of the truck. I am having a hard time believing this. It now has 15000 miles on it and it lasts for 10 to 20 seconds or so at startup. Anyone have any experience with this prob.? Thanx.

    live to wheel, wheel to live--1972 gmc jimmy 8 inch lift, 37" ssr's
     
  2. Sparky87k5

    Sparky87k5 1/2 ton status

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    If you have enough clearance between your pistons and your cylinder walls to hear piston slap, don't expect many miles from that engine. Your clearances appear to be on the edge of acceptable. I would contact GM directly and ask if piston slap that you can hear is normal. Check with GM and find out what factory clearances are is this engine. If it comes to a tear down, you'll have the data to support your case.

    87 K5, 427BBC,D60 & 14BFF, NV4500, NP208, TSM disc's,
     
  3. 3car

    3car 1/2 ton status

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    i agree.this isnt the first time i heard of this on these new vortecs.

    eatin'fords and shittin'dodges down in the sunshine state.
     
  4. MudNurI

    MudNurI 1/2 ton status

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    It really is NOT a Vortec problem- its a "GM" issue- it happens with the duramax's as well as the 6.0 and 8.1's ... matter of fact I have an 89 that has a knock, has had it for quite some time as well- only few minutes after start up- with over 300k miles on it- the engine is still going-- The only thing that you can do is bring it into your dealer AGAIN, and explecitly explain to him/her what the problem is, have them note it in your computerized record--- so when GM finally figures out whats going on- they can correct your's regardless of how many miles are on your truck with our 99- we had to keep bringing ours in for computer updates- you may want to try that avenue- as it seems more and more problems are occuring up till the 2002's- I have not heard/read 1/4 as many problems with the 2002's ticking or knocking- try the computer update.

    Brandy

    LOVING the new Duramax!!!
     
  5. 4x4k20

    4x4k20 1/2 ton status

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    go to www.pickuptruck.com they have a gm forum there there is a lot of talk about the 6.0 knock there

    4x4k20<P ID="edit"><FONT class="small">Edited by 4x4k20 on 12/29/01 08:07 PM.</FONT></P>
     
  6. 82GMC

    82GMC 1/2 ton status

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    Brandy, I have not heard of any piston slap problems with Duramax's are you sure they have this problem? I have heard about the "ticking" problem though. I went to thedieselpages Rondevous (sp?) This summer, The Duramax plant tour was a part of that, Someone did ask someone there about the ticking, And his answer made no sence to me at all, He said it was air bubbles in the oil popping?!?! Seems wierd to me but you never know.

    I am the hunter Who live's in the darkness, And grows through your fears...... And you are the hunted.
     
  7. MudNurI

    MudNurI 1/2 ton status

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    People describe things differently- I can't really tell you if its different or not, but according to John he has heard ours tick/ping what ever you want to call it- I just asumed it was the same sound??? Though he seems to think its a lifter problem with ours- We NEVER heard anything with our 99- maybe it is a different noise? I guess until you hear a Duramax and a Vortec side by side and both are making the noise we can't tell if people are talking about the same thing. I would almost be sure enough to make the statement, that the diesel "sounds" different to begin with, hence the same exact problem could cause the same exact noise, and it would sound different? Again, I'm no master mechanic, but according to what I've read- the problem occurs at the same time, for the same amount of time, with both the vortec's, and the Duramax's? Along with one of our old trucks. I still would have to say to the original poster, to have his computer updated- It may not fix this problem- but there are SES updates for it I'm almost positive. Hope this helps?

    in response to your answer you received from the plant guy- according to our new dealer- ( you could read about our old one with a search I've been screwed by my dealer) GM is more than aware of the problem, however they do not have a fix, and they are still claiming that it is nothing to worry about. Again, it seems that its about a 50/50 problem with these trucks. I can not stress enough to get it in your service record that you complained about it- matter of fact, every time your truck goes in for ANYTHING mention it, and have it put in your record... We mentioned our peeling paint on our 89 a few times- and ended up with the entire truck repainted, sanded down to bare metal etc.. If you don't mention it to them, and its not documented, you will have no recourse when your truck has 75k on it, and your engine is toast.... sorry this is so long!

    Brandy

    Brandy

    LOVING the new Duramax!!!
     
  8. roostr3269

    roostr3269 1/2 ton status

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    Hey Brandy, when u say update the computer, is this a warranty issue? The first time i called gm corporate, they told me they would discuss my "options" with me. Well when they did call back, "options" never entered the discussion. I think its a load of crap when u buy a new vehicle and within a couple thousand miles its slappin or knockin and GM admits there is a defect, but wont do anything. I think i will approach the dealer again about this, and see if maybe i can talk real loud while i am in there about this KNOCKING, so every1 in there can hear me, hehehe. thanx for all the response.

    live to wheel, wheel to live--1972 gmc jimmy 8 inch lift, 37" ssr's
     
  9. 82GMC

    82GMC 1/2 ton status

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    Yes GM is quite aware of the problem, The guy at the plant said they had looked at the problem, And said while they didn't think it's something that will degrade the life of the engine, They hadn't done enough testign to be sure. (At that time of course.) That was in September.
    Roostr, I don't know what to say except good luck! And Hopefully your engine stays in one piece!

    I am the hunter Who live's in the darkness, And grows through your fears...... And you are the hunted.
     
  10. MudNurI

    MudNurI 1/2 ton status

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    When our computer was updated with the '99 it was due to the SES light coming on- it came on and stayed there, the dealer updated the computer- and a few weeks later it came on again- We didn't pay for having this done, and it was done at different dealerships- I would tell the service writer, that your SES light has come on a different times, and stayed on for awhile and then went back out- --- they will try to duplicate the condition and of course, they wont be able to because yours has never done it- however, when you mention that you KNOW that there are computer updates-- they will run your VIN through GM's system, and see if there are any that yours needs. They can pull it up in minutes- The good thing about the computer upgrade is they can not pick and choose what upgrades your truck gets- once they input your vin- they will come up, and the computer will automatically update any and all that your lacking... Also, I would check out <a target="_blank" href=http://www.thedieselpage.com>http://www.thedieselpage.com</a> Becuase there is discussion regarding this in there 6.0 and 8.1 forum- there is a thread on the Duramax forum from a guy that actually thinks he may have found the problem- its quite interesting-- good luck!!! If this doenst make any sense pm, or email me, and I'll try to explain it better--

    --Brandy

    LOVING the new Duramax!!!
     
  11. roostr3269

    roostr3269 1/2 ton status

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    Thanx a lot for the info.

    live to wheel, wheel to live--1972 gmc jimmy 8 inch lift, 37" ssr's
     
  12. IGOR

    IGOR 1/2 ton status Premium Member

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    So if given the chance, would all of you that own new GM rigs buy one again - or would you go Ford or Dodge?

    I ask because I'm in the market right now...
     
  13. BARRAZA

    BARRAZA 1/2 ton status

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    There have been a lot of posts on other boards that I have been following regarding this subject. It appears that it is not a GM problem, the noise has occurred in many other makes (FORD had a lot of these problems too). The problem seems to center around the Hypereutectic pistons that are now used, and as someone who built his own "knocker", I have my .02 to contribute. I think that because of the output and designed usage of these engines, ie 300 plus ftlb of torque and high gross wt and tow ratings, hypereutectic pistons were the best choice. These pistons are much stronger than a cast piston and much less expensive than forged piston. They typically run at wall clearances greater than cast pistons(always quiet) and less than forgings(can be somewhat noisey). These reasons are why I picked them for the 383 in my truck. I asked the machine shop to bore the block at the min recommended clearance but when I was doing the assembly I discovered they bored to the high side of recommendations. Guess what, it has the exact same symptoms as the engines in the new trucks, knocks a little for 15-30 seconds on cold start. I think it would suprise many people that pistons are not round when cold nor are the sides straight up and down. In fact there is quite a lot of taper in the sides of a piston, my guess is that the hypereutectic pistons are more sensitive to clearances as far as noise goes. They make a louder cold knock than the forged pistons in two other motors I have but the knock quiets sooner. The 383 now has about 90k miles on it and runs just like the day it was new. I think it all comes down to whether or not they wanted to take 50-75 ftlbs out of the motors and use cast pistons to please everyones ears or add the cost and the noise of forged pistons (given how quiet these new trucks are, you would definitely hear them). BTW I also have a 2002 Z71 with a 5.3 and it's quiet as a mouse. Has it been that long ago that we listened for (and liked) the rattle of cold forged pistons as an indication of serious power?
     
  14. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Make sure you use 5W30 weight oil. I have heard this is often a problem if you use heavier oil.

    I would absolutely insist that they change the engine if it persists. I would not let them make excuses. If they continue to make excuses, take it back a few times, get it documented, and make them buy it back as a lemon.

    There is absolutely no reason that an engine should knock "normally". I don't care what kind of pistons they use. Piston slap is piston slap--and there's no reason they should have bored the motor too much to where it's going to make noise.

    I wouldn't care if it'd last 500,000 miles--if it made a funny noise and I payed what they want for a new pickup truck, they'd sure as hell be taking it back. 30+ grand for a truck is absurd. It better do everything I want for that kind of money.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  15. MudNurI

    MudNurI 1/2 ton status

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    A vehicle is not considered a lemon- unless it has been to the dealership to be fixed, they have attempted and the problem consists,,, ususally more than 3 times- the situation with these trucks is not the same, you can take it to the dealership, however they WILL NOT ATTEMPT to fix it, because they CAN NOT... its pretty simple really-- but your post makes it sound as if those of us with these trucks can just walk back into the dealership and say- hmm sorry I don't like the way the seat feels, you can have it back- its the same situation. The truck has no loss of power, still runs every day, starts, stops, doesnt stall, can still pull the house down etc.. hence there is nothing "wrong" with the truck... by stating you would absolutely insist that they change the engine is just plain nonsense- Lets think about this- Joe has a truck, he doesnt like the way the engine sounds, he gets it replaced, jack has one, he doesnt like the way the ali shifts, he gets a new one etc.. think about what would happen to the companies if they did that. I'm not saying that there are not people that have gotten lemons, there are... however these new trucks are not lemons, and it doesnt matter WHAT is said/done/etc... they are not going to fix it, at this time anyway- who knows maybe in 2-3 months, there will be a recall...Regardless, I hate to say it but short of everything in my previous posts, there insn't much to do...documentation is the only way to go.... The other thing 5W30 is not the recommended oil for these engines, believe it or not is is 10W40... our dealer put in 5W40 in our new d/a,( the recommendation for our area) due to where we live and the cold weather, but running oil that is not the recommended - that is the one listed in the back of your owners manual- may end up biting you in the butt in the end. Especially if you have it done at a dealer's... where they have record of what type of oil you have. I really have no choice but to run syntetic fluids in my truck- why? because it is the "recommended fluid" yup it costs more, but if my rear end blows up in 20k miles, I have documentation that it was changed and filled at the "recommended" times with the "recommended" fluids. I'm not saying your wrong with your post, this is just my .02.... I believe most people would agree with me...

    Brandy

    LOVING the new Duramax!!!
     
  16. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I don't know what engine you're talking about--but I worked at a Jiffy Lube and all of them said 5W-30 on the cap.

    Their are plenty of manufacturers engine defects I can think of that don't cause drivability problems. To say that because it still drives and has plenty of power, so there's not a defect is complete bullshit.

    It's a new truck. The engine should not knock under any circumstances. If it does, something is wrong.

    If they bored it too big, they sure as hell better replace that engine, or bore it .030 and put oversize pistons in it.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  17. MudNurI

    MudNurI 1/2 ton status

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    but exactly what "proof" does anyone have that the engine was bored incorrectly? has anyone had any problems with any component associated to the knock? NO not one- (that I am aware of, and from the posts on the boards with this as a topic).. that is what my point is, they are not going to replace anything until there is a problem caused.

    Our truck is a 2001 2500HD Duramax, ali combo- and it specifically states "the recommended oil for this truck is 10W40" in the owner's manual, where they have a graft showing the different viscosities and the levels of protection.

    Chevy has a "slip" in there rearends- that has been there since at least 89- our 89 did it the day it came off the dealers lot, and has done it daily since.... I mentioned it numerous times when it went to the dealers- now you could say any rearend that klunks is junk etc.. well I'll tell you, the truck has close to 400K miles on it, and we have done NOTHING to the rear end, other than grease etc.... I could have bitched complained been pissed about it etc.. but I take GM's word for it, they built the damn thing, and if they tell me that its "okay" for the klunk, then by golly it must be. and from the way the truck has been run/driven, if it was a weak rear end, it would have been on someones driveway by now- we have plowed with that truck the winter it was new- thats 11 winters, 11 vermont winters, and the rearend has stayed in one piece. LIke I said before, documentation is the only way to protect oneself in this kind of situation.regardless of what you as the consumer may think is wrong with your truck- you can't just "make them buy it back" its just not that simple. You would think after 42k I could if I wanted to but you can't....plain and simple.

    I'm not saying since it still drives etc.. that there is no defect- what I am saying is that you can not prove the truck is a lemon....if that was the case, you coudl say becasue there was a rattle in the dash, it was a lemon if they couldn't find it... its a new truck, with a new engine tranny combo- there are going to be bugs worked out of it. HENCE THE COMPUTER UPGRADES. these new trucks are A LOT different from the old ones, who knows, maybe it IS SUPPOSE to knock? there is a post on dieselpage regarding someone who thinks he may have found the problem, matter of fact I emailed the original poster of this post the entire thread, seems to be it may be something as simple as he thought- some little flap flappin- I don't have the post right here, but I tell ya it made sense, and it actually had NOTHING to do with the Engine itself- Again, just my .02, don't bash me from it!

    Brandy

    LOVING the new Duramax!!!
     
  18. 84_Chevy_K10

    84_Chevy_K10 Banned

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    The proof that they bored it too much is that it knocks. Like I said, a new truck with 15,000 miles that knocks is a bunch of BS. THE KNOCK IS THE PROBLEM. What are you talking about, "has anyone had any problems with any component associated to the knock? NO not one- (that I am aware of, and from the posts on the boards with this as a topic).. that is what my point is, they are not going to replace anything until there is a problem caused. "?

    The fact that a new truck knocks isn't enough for you? To me that is unacceptable, and to most other people that work on engines, they'd think the same thing.

    If my new truck knocked, I wouldn't take any chances. If it knocks, something is wrong with it.

    Obviously you have little to know mechanical knowledge if all you do is quote other messege boards or the owner's manual, and think that the knock is okay.

    No new engine that knocks is okay in my opinion. If you find that acceptable, great, your truck came with the special feature that makes it sound like it's got 300,000 miles on it when you start it. I know I'd find that a real attractive feature if I bought a new truck, piston slap.

    I was talking about gas engines. I've never heard of putting anything but 15W40 in a Diesel engine anyway and regardless of what was recommended, that's what I'd use.

    As for the Alison comment, recommended engine oil has absolutely nothing to do with transmission type.

    How about some connecting rod knock to go with your piston slap? Would it be a lemon then?

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  19. blazer72

    blazer72 1/2 ton status

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    I haved had our 01 with the 8.1 in 2 times now doue to engine nosie I was told by to delres that as long as the start up sound goes away with in 3 min they will not due anything. So I will take it to gem for every oil change and every time I will have them time the knock and valve ratel till it goes away since GM gets to fix its for any thing for the next 120,000 miles I dont care what they do

    72 Blazer 400TPI NV4500 NP203/205, 6 bolt FF14
    01 Suburban 8100 2500 4X4
     
  20. Twiz

    Twiz 1/2 ton status

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    As per SI 2000, 12/'01.

    Bullitin #01-06-01-022

    Engine Knock on Cold Start
    2001-2002 Chev and GMC p/u with 6.0L

    Some of the above vehicles may exhibit an engine knock noise that begins in the first several thousand miles of use. The knock noise is most often noticed during initial (cold) start-up and typically disappears as the engine warms up.

    This noise may be caused by an interaction between the piston and cyl wall. GM Powertrain Engineering, and an analysis of engines returned with this condition, has cofirmed that the noise is not detrimental to performance, reliability, or durability of the engine. The noise does not have any effect on the longevity of any of the engine components.

    <font color=red>Important
    At this time, replaceing the engine assembly or pistons will not eliminate this noise. </font color=red>

    Please share the information found in this bullitn with customers who inquire about this condition. In the event they have additional questions or concerns, please advise them to contact Customer Assistance at the numbers listed below.

    Chevroltt 1-800-222-1020
    GMC 1-800-462-8782
    Canada 1-800-263-3777

    Probably not what you wanted to hear, but thats what I found. If you took it to a dealer, and made a complaint. The concern is now on record and G.M. should and will take care of you, in the event that something does happen, or the bullitin is updated.




    <font color=blue>Wow Factor
    A SBC at 6000 RPM, Piston speed of 60 MPH.
    3- The intake charge reaches a speed 4 X greater than the piston.
    Thats 240 MPH.
     

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