GM Engine Knock

starnuts · September 2002

The GMC Area Service Manager has just agreed to replace my 6.0L engine in my 2002 1500HD with 12K miles. It knocks for over 10 minutes (idling) when started first thing in the morning. He says the new engine has "higher mass coated pistons with improved piston to cylinder clearance and a new heavy duty crank shaft. Engine part number is: 88984277. Can anyone confirm that this engine is an improvement ??

Thanks,
Nick
Dallas

gator36 · September 2002

GM Did change the motors for the 2003 MY.
I talked with a GM powertrain engineer.
He stated that they did tighted the clearances on the piston to bore clearance. The pistons all have a polymer coating on them, apparently there is a slight change in the engines now being produced.
GM Powertrain refers to the psiton slap as a Engine tick. He explained why the tick would go away after the famous de-carbonizing. He also stated that there are some motors with other problems that are being incorrectly diagnosed as piston slap. Generally a very helpful person to talk to .

Walter (Gator36)

egarcia528 · September 2002

Is the engine knock problem limited to newer GM engines? My 96 suburban is knocking during cold starts and then it goes away. Hard acceleration makes the engine knock. I heard that the piston slap issue does not apply to my engine type. Is this true?

obyone · September 2002

Hard acceleration makes the engine ping. Cold start knock is an entirely different issue. There's also bearing knock.

99-06-01-003 APR 99 Engine Bearing Knock Noise

sonjaab · September 2002

Side by side parked in my motel for a
week. We had the Bass Masters fishing
tourney. 6.0 , 8.1s crews, excabs.
Listened to each one every morning and
asked the guys about cold start knock.
All the guys had the fuel rail and injector
tick at idle. Only one guy who lived in
Northen Canada complained about cold start
knock in the winter only..summer its gone
he says..I said me too !
Out of 18 rigs and fancy fishing boats
5 fords and 1 mopar......geo

tep · September 2002

I have a 2001 5.3L knocker (it pings, too) and have submitted last two oil changes for analysis. First analysis at 10,500 mi (not first change, of course) showed elevated copper, tin, and silicon. Latest analysis at 15,750 showed improving levels to near universal averages.

Comment from lab: "You can see your metals improving as it passes through wear-in stage. Copper and tin both dropped to within-average levels, and silicon decreased as well. Although none of these elements is at the universal averages quite yet, we suspect they will get there within the next two or three oil changes. We did not find any unusual moisture, antifreeze, or fuel in the oil. Insolubles were average at 0.4%, showing good filtration. It looks like this is going to be a nice engine for you."

FYI, am using Mobil 1 and Pure One filters. I may wait an oil change or two before submitting another sample. I am trying to be a little less compulsive as I get older, and decided with this truck to wait until the Oil Life monitor tells me it's time to change rather than using an arbitrary number, but I don't know if my conscience will ever let it get to be much over 7500 mi.

tep

noobie1 · September 2002

I'd be interested to know what the power train engineer's explanation is about the relationship between carbon build-up and the tick (knock).

tep; Interesting. I've had similar comments from Blackstone. Is that the lab you're using?

-David

tep · September 2002

noobie: Yes, I'm using Blackstone. They are very prompt in getting the sample tested and in getting shipping materials out.

It certainly remains to be seen if indeed this is going to be "a nice engine." I plan on driving the thing into the ground. Hopefully the ground comes sometime after 10 years and 150k miles or so!!

tep

noobie1 · September 2002

I really like them too. I've only used them once, at the third change (9000 mi.), but I appreciate their honesty; Their comments to me were about the same as yours: drive it two or three more changes to get an accurate read.
Their site is where I first heard of by-pass (off-line) filtration which I plan to install on my truck at the next change. Though they don't sell them, yet are very high on them, I think it's fair to conclude there must be some benefit.
Given your conscientious attitude about care, you should have no problem meeting your mileage goals. Lots of vehicles get there with less.

-David

xyz71 · September 2002

I agree with you - I changed to M-1 in both of my trucks - 99 Z-71 and a 2001 Tahoe - 5.3L engines.
I also decided to relax and just let the oil life monitor tell me when it is time to change. I was a complete fanatic before - Once - during a vacation trip - pulled into a Jiffy Lube with 2,999 miles since last change - I was only 250 miles from home.

So far the 99 Z-71 wanted a change after 137 hours and 3,400 miles 4.5 months; 132 hours and 3,300 miles about 4.5 months; 135 hours and 3,600 miles about 5 months; 128 hours and 4,800 miles 3 months. (Obviously the 4,800 miles included a long highway trip).

Tahoe light came on after 157 hours and 3,800 miles 5.5 months.

Some would say I am wasting $$ changing this often (M-1 should go at least 5K) but I say what the hell I change it myself and for a little more than $20 it gives me peace of mind.

My Z-71 has 3,300 miles and 130 hours since last change - so I guess it will light up any day now.

gator36 · September 2002

Regarding the carbon buildup...
The engineer refers to what we have used blanketly or more accurately the dealers have, Piston Slap, as an engine tick.
From what we discussed, the general negative connotation at the dealerships leads to some engines being mis diagnosed as having piston slap or the "engine tick".

The tick is caused by a buildup of carbon, not on the crown of the piston, but on the side. Now I cannot remember if it was between the top of the piston and the first compression ring or between number one and two compression rings. However this buildup is what is causing the the tick upon startup. When they de-carbonize the motor, the carbon is not there to interfere.
In my case, I have it warm, cold, on a hill, pretty much all of the time. There are documented cases where there are other problems. It is my belief that the engine tick is the most common problem. Yet no one can say this is exactly what it sounds like. There is speculation that I may have a wrist pin knock. Yet try to get the dealer to look at it after all of the corporate bs and tsbs from gm.

The engineer also aluded to a few engines with an o-ring that was torn on installtion of the oil pickup tube.

I hope this helps.
I will say this. I had piston slap on my 97 GMC 5.0l and it was running fine at 150K miles when I sold it. It did not burn oil (or at least as far as I could tell) and I definately was not a grannie on the gas pedal... The piston slap on the 5.0 GMC was not the noise I have in my current 5.3.

Walter (Gator)

noobie1 · September 2002

I'm still curious about the de-carbonizing. Have you ever had it done? Did it provide a temporary solution as most say? For the do-it-youself'ers, do you know the procedure?
Thanks for your help.

-David

gator36 · September 2002

As far as the proceedure, results and whether or not i have had it done...

I have not had it done... Others have reported on this board that they had theirs done and it worked for several thousand miles....

From what I have read about the proceedure. It requires 2 oil changes a special solvent and from what I understand a tool to load the solvent into the cylinders. It is possible for the initiated, yet you will need a delivery method to get it into the cylinders.

After a soak, they evacuate the cylinders and change the oil. They suggest a short drive to clean out the rest of the solvent and the remaining carbon. Then one more oil change to clear out the remaining solvent...

This is what I read once on a TSB with the proceedure for this process....

Walter

rayt2 · September 2002

I also have the knock, have gotten the ext. componenet warranty from GM for the engine but expect them to do their usual...........nothing! I plan on running this truck for at least 10 years like my last. I change oil/filter @ 5k or unless doing a lot of towing, then when the Oil Life monitor kicks in. Regular ole 5w30 dino juice is all Iv'e ever used, the synthetics just make CEO's richer!
What I will be doing before the 3/36 runs out is purchase an extended warranty from Warranty Gold (GM won't get my money for theirs) to cover everything for the next 7 yrs/100k, by then I'll sell it and buy another new. I have lost my faith in GM's products as far as reliability goes since the knock issue inflicted my 5.3 and their take it or leave it attitude. They very well may have sold me my last GM product, time will tell when I'm ready for another new truck on what brand it'll be.

Ray T.

gm02 · September 2002

...is through who? I thought that was GM warranty offering. On the web found a GM warranty, 5/75K for $950 w/$100 deduct.
Thanks

starnuts · September 2002

The dealer wanted to try the decarbon on my engine before he would go to bat for me on a buy back or engine replacement. It was at 11K miles. Neither I nor the service manager thought it would do any good, but he said he had to try it before proceeding. Surprisingly, after the treatment, no more noise; none !! It was very quiet on a cold start the day I picked it up. I drove it about 75 miles that day. The next day cold start at home and the noise was back; exactly the way it was before. Can't explain why. Mine clatters for up to 10 minutes after cold start and anytime after it cools from full operating temp. Now, the new 6.0L engine is on order; should be here this week.

Nick

rayt2 · September 2002

Warranty Gold is out of Texas and been in business for 18 years. I was quoted for their diamond plan w/$50 ded. 5yr/100k $1180, 5yr/150k $1604, 6yr/100k $1204 & 7yr/100k $1254. Coverage starts from date of purchase, mileage runs to the plan bought. For instance, I buy the 5yr/100k plan I effectively get 8 yrs and 100k coverage. The catch is to buy before the last 1000 miles of your factory warranty otherwise you can only purchase as a used car policy. There is a topic on Warranty Gold in the "maintenance & repair" board on Edmunds for more info and to ask Warranty Gold rep directly since they follow the board.

Ray T.

rayt2 · September 2002

Warranty Gold is under Finance,Warranty & Insurance discussion board.

Ray T.

starnuts · September 2002

I just got a call from the dealer. My new 6.0L engine is in. I'm dropping mine off there tonight. They said it would take two full days, maybe three to remove and replace. I'll let you all know how it turns out.

Nick

starnuts · September 2002

Picked up my truck yesterday with the new 6.0L engine installed. It took the dealer a day and a half to do the install. The truck was spotless when I picked it up and ran fine. I can find nothing wrong with it: smooth, quiet, no internal abnormal engine noises, everything else appears to still work on the truck. Only time will tell if the new part number engine really prevents the slapping. My congrats to my dealer, Sewell GMC in Dallas for going to bat for me to get a new engine. I'd do business with them again, even if this engine turns out to be no better than the first.

Nick

noobie1 · September 2002

Congratulations! And thanks for the info. I wish my dealer were like yours. All I get is the 'normal' runaround. Quality Chevrolet in Escondido, Ca in case anyone wants to be forewarned.

-David

rfisher7381 · October 2002

Has anyone been promised that a repair for the piston slap problem was due soon? I heard that new engines were going to be offered for the 6L and new piston/rod assemblies for the 5.3L but my dealer keeps saying he hasn't heard anything yet. I've been following the gm piston slap website but no recent reports of corrective action have shown up. I have a 2500HD 2001 w/6L engine which has piston slap but isn't using oil (at least yet!).

obyone · October 2002

planned on doing.....which is nothing.

pally · November 2002

The guy who was running the slap site was threatend by GM and now the site has dissappeared! Hmmmmmm?

ryanbab · November 2002

"The guy who was running the slap site was threatend by GM"

He was? Did they put a hit out on him or something?

jtt3 · November 2002

http://gmpistonslap.tripod.com/

rayt2 · November 2002

Site was not shut down it was under refinement. GM tried o bully their way in on John but it didn't work just gave him more resolve to push on instead. The new website is even better then the last.

Ray T.

obyone · November 2002

on his HD at pickuptrucks.com. Topics getting long too. Seems everyone's interested in getting a new motor....hmmmmm. Also that there is a TSB out to address the knock with 6.0 being replaced and 5.3 getting new pistons. Check it out...I'd post a link but....well you know.

gmpistonslap · November 2002

Just to clarify John had nothing to do with the launch of the new website at gmpistonslap.tripod.com and in fact has disappeared. I own a website company and a GMC slapper and decided to take over upon John's disappearance. Look for the new site to grow in a more organized fashion!

Webmaster Dan

whatsachevy · November 2002

of any known engine problems as a result of the ticking noise at start-up. My '01 2500HD 6.0 has ticked since about 5 or 6K. I now have 22K. The noise is no louder and doesn't last any longer than it ever did. It uses no oil between changes and is driven pretty hard. My buddy's '97 GMC 1500 5.7 now has 115K (110K knocking). It still doesn't use any oil and has been, by far, the most ill-treated truck I have ever seen (including stuck in a pond with muddy water up to the bottom of the dash - I only wish I had a picture). I say drive 'em hard and worry when, and if, people actually start having problems.

ryanbab · November 2002

I wouldnt trust an engine replacement. Much more than engine noise can go wrong

I still have not heard of any performance issues or engine malfunctions due to any engine noise (i am not talking about oil consumption either)

to quote someone "if it aint broke why fix it?"

gmengineman1 · November 2002

For noobie of Escondido, CA. Tell your dealer service writer that you want to speak to the Service Manager. Tell him that you wish to have a conference with the Chevrolet Zone Manager. Tell him what your concerns are. If he asks what do you want to fix the problem. Tell him right out up front what it will take to satisfy you. Check on the California Lemon law provisions and see if you meet that criteria. Chevrolet has had to "buy back" several vehicles of the '01-'02 model year. They're not happy about it. But you have to get determined enogh to be a burr in their saddle. Then they'll start to listen. There are several Lemon Law lawyers in the San Diego area who thrive on cases like yours. Find one in the yellow pages.

noobie1 · November 2002

All your thoughts are well appreciated. Thanks for your interest. What you're talking about is a major commitment. I understand that GM has likely calculated that most people like me will wimp out and just go away; The process seems designed to impede and discourage; Time constraints, aggravation, etc., all rational excuses for weaseling out of what we know is responsible reaction. I'm still sitting on the fence about it.

-David

rayt2 · November 2002

Get off the fence and go proactive don't become a victim to the corporate giant! I had to face them over a lemon law case in 1987. I had my documentation and 8 times back to dealer for same problem. I represented myself against the GM lawyer and dealership service manager, I won GM lost.

Ray T.

rayt2 · November 2002

Thanks for the correction on my last post re:GM Piston Slap website. I wasn't aware John has dissappeared (did the corporate bully get him ???LOL)
You have done an excellent job with the NEW site, thanks for keeping up the good fight.
My Y2K knocker still knock'in after almost 35k miles to date.
No adverse effects (other than it sounding like it wants to be a diesel) so far but time will tell.

Ray T.

ryanbab · November 2002

Just wondering does your knock every day?

Mine did sunday morning and hasnt since (today is tuesday).

rayt2 · November 2002

Knocks on every cold start regardless of ambient temperature, built Chevy Tough my [non-permissible content removed]! I still enjoy this truck regardless but it doesn't say much for Chevy's claim. They still have the largest extended cab on the market yet!

Ray T.

ryanbab · November 2002

Also i notice that my knock is never the same sound noise wise. One day it is loud next day i dont hear it next it is faint.

I would have to say all the rattles in the cab drive me more crazy than the engine knock. I am just baffled

obyone · November 2002

With all the problems I've had with my truck, the one thing that I never had was problems with rattles. Perhaps you need to put back correctly what you once took apart? LMAO!! Course you could always crank up the radio.....

ryanbab · November 2002

"you need to put back correctly what you once took apart? "

haha

hmmm dash has been apart, pass side door was apart, rear seat was taken out, both rear door panels taken off, etc

I have to say taking the pass side door off and adding a strip of 3m tape in one spot stopped that rattle

I think the main reason for the rattles is the weather. Lots of up and down temps. During the day its 50-70 and at night 20-40

burnsome · December 2002

I dont know if anyone else has had the same experience that I've had with my "knocker", but here's what I've done from the maintenance side of the issue and it has helped. I would describe my 2001 1500 Z71 as more of a cold start "ticker" and not as much a "knocker". The sound started when the engine hit around 10K miles. I now have 30K miles on it and it does not use any oil between changes. I complained to the dealer, and got the same run around everyone else is getting. I decided to experiment with a few things to see if there was anything that helped and here's what I found, at least for my truck. Two things I've done that have helped, if not completeley stopped the cold start tick:

1. I switched to Mobil 1 oil in the heavy weight (15W something) in the summers and use 10W-30 during the winter months. The owners manual says to not use any oil heavier than 20W something, so I figure 15W should be ok...either the change in brand (Mobil) or oil weight did help just a bit by reducing the perceived noise upon cold start cranking. I ran the cheap Valvoline oil before switching to Mobil 1 synthetic, and it was definately a louder nose the engine produced, especially after a fresh oil change. I've also noticed that the more miles on the oil change, the less the noise. A fresh oil change seems to make it more noticeable for a week or so. When using the 5W-30 Mobil 1, the noise is back, so I think the cold start cranking viscocity is not good for eliminating the noise. Using the heavier weight oils helped reduce the engine noise, but did not eliminate it completeley.

2. Upon cranking the motor, I immediately put the transmission in to reverse (or drive) as I back out of the carport. There is no ticking sound if the motor stays at a "lower than idle" RPM in my truck. This has helped more than anything to eliminate the ticking noise. It is normally completely eliminated.

3. I also let the engine warm up a bit before hitting the road. My driveway is about 100 yards long, so i just let the truck idle down the drive. Upon turning onto the road, I give it about another 100 yards of idling until picking up speed.

I know it sounds like a pain, and it is, but it's the only way I've found to keep the motor from making the dreaded ticking or knocking noise. I like the truck otherwise and have no other complaints, otherwise I would trade it in for something else. I do have the 100K mile extended warranty, so if the motor blows or otherwise tears up, so be it...i'll probably go with a diesel for my next truck purchase anyway...

my .02 cents worth........

YMMV....

rayt2 · December 2002

Mine developed around 17k and w/36k on ticker it still knocks, ticks, bangs or whatever for first minute during cold start. I look for the oil pressure gauge to respond let it run for a couple minutes then I'm on my way. As some have called it this issue is an anoyance and will probably be with the truck till I part with it in 5 or 6 more years. I also have the the extended component warranty from GM which would be a test in itself if I ever had to use it. GM will turn up the GM B.S. spin cycle and dance around before ever honoring it I'm sure.
My biggest complaint with the condition will be during resale since it is a deterent when selling a vehicle to have the engine knocking no matter what warranty you have .
I just purchased an Extended Service Plan that covers me on everything till 100k then I move on to another truck.

Ray T.

gator36 · December 2002

I just saw this one,

Engine Knock or Lifter Noise (Replace O-Ring)

#02-06-01-038

4.8, 5.3, 5.7 or 6.0 V8 Engines...

rayt2 · December 2002

Do you have the full TSB, I'll go in to dealer with guns loaded if I have the TSB in hand. They said they would call me when a fix came from GM, I won't wait for that call.

Ray T.

jtt3 · December 2002

Here is a site that lists TSB's and I don't know how often it is updated so maybe keep an eye on it. Click on different months and then bulletins.

http://service.gm.com/gmtechlink/images/issues/archive.html

rayt2 · December 2002

The TSB is not listed there nor yet on All Data

Ray T.

guy21 · December 2002

Has anyone had experience with a knocking engine failing. I spoke with a friend yesterday whose brother in law has a 2001 5.3L which failed in his Silverado at 67,000 miles. One of the connecting rods broke. GM apparently says "too bad". The guy could live with that except he had purchased a GM extended warranty to 60,000.

gator36 · December 2002

Engine Knock or Lifter Noise (Replace O-Ring) #02-06-01-038 - (12/02/2002)
Engine Knock or Lifter Noise (Replace O-Ring)
2001-2002 Chevrolet Camaro

2001-2003 Chevrolet Corvette

2001-2002 Pontiac Firebird

2002-2003 Cadillac Escalade, Escalade EXT

2000-2003 Chevrolet Suburban, Tahoe

2001-2003 Chevrolet Silverado

2002-2003 Chevrolet Avalanche

2000-2003 GMC Yukon, Yukon XL

2001-2003 GMC Sierra

with 4.8L, 5.3L, 5.7L or 6.0L V8 Engine (VINs V, T, Z, G, S, N, U -- RPOs LR4, LM7, L59, LS1, LS6, LQ9, LQ4)

Condition
Some customers may comment on an engine tick noise. The distinguishing characteristic of this condition is that it likely will have been present since new, and is typically noticed within the first 161-322 km (100-200 mi). The noise may often be diagnosed as a collapsed lifter. Additionally, the noise may be present at cold start and appear to diminish and then return as the engine warms to operating temperature. This noise is different from other noises that may begin to occur at 3219-4828 km (2000-3000 mi).

Cause
The O-ring seal between the oil pump screen and the oil pump may be cut, causing aeration of the oil.

Correction
Inspect the O-ring seal and replace as necessary. Use the applicable part number listed below. Refer to the Engine Mechanical sub-section of the appropriate Service Manual.

Parts Information
Part Number
Description
Qty

12557752
Seal-O/Pmp (O-ring)

(F and Y Cars)
1

12563963
Seal-O/Pmp (O-ring)

(C/K Trucks)
1

Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Usage
Labor Time

J1060
Pickup Tube and Screen - Replace
F Car
3.7 hrs

Y Car
4.3 hrs

C Truck
1.3 hrs

K Truck
2.1 hrs

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© Copyright General Motors Corporation. All Rights Reserved.

rayt2 · December 2002

GM was handing out Extended Component Warranties for the engine knock issue like candy to those who documented and bitched enough, did you friend get one??? If so he is covered, if not he may still have a case but needs proof GM was appeasing us whiners. I can e-mail him a copy of my letter if he needs some ammunition to fight the corporate dogs.
This is the first reported failure I have heard of with the Chevy Knockerado's.

Gator, thanks for the full lsting on that TSB for our knockers.

Ray T.

gator36 · December 2002

You didn't hear it from me.....

GM Engine Knock

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