GM ENGINE KNOCK

bamatundra

Many DOHC engines have buckets over the valve springs. The cam acts directly on the buckets. To adjust the valves you shim the buckets.

My Acura 1987 DOHC had short rockers which allowed for easy valve adjustment.

My 1995 Nissan Maxima V6 DOHC has hydraulic valve adjusters.

seelig

how can someone with such a vast knowledge (on everything) of trucks and what not, make such a poor decision by buying a Tundra?
i ask this because after not reading here for quite some time, i decided to catch up on the Chevy topics. obviously you have caused your usual "rucuss" as there seem to be a lot of posts missing.
PLEEZ, if you can, quit with the emotional replies and HOGWASH. it's old and annoying. i have grandchildren with better dialogue than you.
this topic and others like it are for chevy/gmc owners that would like to know facts that concern their vehicles.

4x4man

Thanks all for the responses....

Well the story is (From Corporate Saturn) that what we are all hearing is normal valvetrain noise due to the fact the engine has an aluminum block and head and instead of having a timing belt, it has a steel timing chain and the noise I am hearing is all that noise coming through the engine from the chain and the solid lifters. I think they mean tappets, I looked at a cut out of the engine while I was at the dealer and it shows what looks to be a large lifter about the same size as the valve spring (in diameter) that is on top of the valve and the cam lobes riding on top of that lifter or tappet. Those are tappets right?? Well anyway, they want me to drive it for a little while longer and keep them posted if the noise gets any better or worse. Maybe changing to synthetic oil might help get the oil up there quicker to quiet the noise faster. I duno...we'll see.

Bob

gm02

Just got word last night that GM is sending me a "Component Letter" that will give me a 5year 60K mile extended warranty on the engine & drive tran only of my 99 Montana due to the engine knock. Seems like a lot of folks were getting the Major Guard which is bumper to bumper. Even mentioned to GM I wanted to upgrade to the Major Guard and pay the difference....no can do.

Hope the new Rado doesn't have any problems.

ryanbab

i got a 100K 5 yr engine component warranty last wk.

joe3891

Any 5 yr warranty i ever saw from GM starts from day one,in other words 2 yrs beyond 36 36.

rayt2

E-Mail me the particulars on how you got this, I am going to use it for ammunition when I state my case for the extended warranty. Did you file w/BBB or just deal directly w/GM Customer Service?? Inquiring minds want to know!

Thanks..........Ray T.

gator36

I too was offered the GMPP basic guard.
Be careful here. I would suggest the GMPP major gaurd to anyone who has a truck. I purchased it for my 1997 GMC Sierra and it paid for itself in spades. It is prettymuch a hassle free repair on the major gaurd. The Basic gaurd only covers the drivetrain. I have yet to get a full component list of what is covered but I am sure it does not cover a/c and such.
I had called the GM CAC to document the engine knock. They in turn offered me the Basic gaurd 5/100.

FYI

Walter

ryanbab

sorry can it wait till next wk? Email me so i dont forget. My computer broke today (keyboard problems) and i had to send it in. Wont get it back till wed probably. I spoke directly with gm customer assistance no bbb

whatsachevy

I got the 5-year/100K by calling GM Customer Service at 1-800-222-1020. I will fax you a copy of the letter if you would like. E-mail me your fax number or post it here and I'll send you the fax.

ricsch

pulling out Tundras!!! Okay, when you called the customer service number, had you already had repair orders for the problem, or how wer they willing to give you the warranty?

whatsachevy

Yes, I did report the problem to my dealer and had it noted on a repair order, but no attempted fixes were ever performed by the dealer. I just wanted to make sure that I had the reported problem on record. I made a comment about the problem on the Service Order questionnaire that was mailed to me and GM Customer Service actually contacted me. After discussing the possibility of receiving a free extended warranty, GM Customer Service contacted my dealer to verify that the problem had been reported. GM Customer Service then called me back and told me they would send me a letter stating that my vehicle would be covered for 5-years/100,000 miles for the engine and all internal engine components. I personally don't think that the longevity of the engine is compromised and am not really in favor of someone tearing into my engine. I never intended to have the engine repaired (I would accept a totally new complete engine - although I didn't really expect that would ever happen). I figured if GM might for some reason replace the engines, it would at least be known that I had experienced the knocking. I was really hoping that I could just get an extended warranty out of the deal, and what do you know, it worked!

dodgeram10

Isn't knocking noise from GM engines normal, Coolant leaks from the 350 intake gaskets are normal.

whatsachevy

any Dodge owners ought to be bashing other makes regarding problems. At least Chevy and Ford can build transmissions that last longer than 50K.

dodgeram10

The GM 4L60E transmissions break down more then any Dodge trans, The sun shell breaks on just about every 4L60E trans.

whatsachevy

That's odd. I know six people who have Chevy 2500's (model years 1987 - 2001) and not one single transmission problem. I know three people with Dodge's (2 with 2500's and 1 with a 1500) and all three have had transmissions replaced before 60K. I'm not sure where you are getting your data. It must be from Bamatundra!

rayt2

Your story about how you reported engine knock is identical to mine. I complained about it at service visit, they noted it and replied on bottom of ticket "GM is aware of problem and is working on a fix", so that's all I have to go with and no way will I allow them to do a top end soak for decarbon, that's a waste of time.
It's funny though, I also got the questionaire, sent it back and have heard nothing from GM. I told them that if engine knock is nothing to worry about then back up their words with an extended warranty to 100,000 miles unlimited years, maybe that pissed them off who knows? I also don't think the knock will effect the life of the engine but I have never had a new engine make this kind of clatter on start up even if it only lasts for 30 seconds or so. It's not normal!
I will e-mail my fax give me all the particulars...thanks

Ray T.

obyone

Just wondering if any of you did an oil analysis? Curious to see hwat it would turn up. I mean for $20 seems like an idea.

seelig

but that's a good idea. think i'll have it done.

xyz71

99 Silverado LT Z-71 5.3L had a slight start up knock. I changed to M-1 5W30 before a 2,700 mile highway trip. My knock went away. I thought it would come back - but it has not -I have put on about 1,500 knock free miles since trip.

gator36

I have had 2 analysis done on my oil.

My knock seems to last alot longer than 2 minutes. I have yet to time it, but by general counting it lasts 3 minutes. Both of my analysis I have sent off were done by Blackstone Labs.

I posted the second results in the maint board

gator36 "Oil Analyst Sites." Feb 7, 2002 12:25pm

Post 53. The justification is off. But the numbers are in this order. Last, Average, first, Industry average.

So far they state the Copper is from the factory fill oil but we will see on my next sample.

The high's as I see it are the copper being more than three times the Universal average
and the Tin being just slightly above normal. The high readings at the bottom are for detergents
added to the oil.

I am sending another sample in on Monday. I think with the samples I am covering my rear.

kg11

Does anyone else have the knock in thier 8.1?Mine has 17k on it and it sounds like a lack of oil pressure for 30-45 sec when I start it.I'm using Mobil 1 (5-30)since it was new(79 mi)
kip

obyone

Agreed on the copper. Blackstone cant figure it out cause the sample virgin Lubriplate oil I sent them contained no copper and I've been off of the factory fill for 30K miles. So where is the copper coming from? My reading was something like 2700. BTW, I don't have the knock on start up or any knocking at all.

minikin

Basicly a repeat of something I posted on one of these boards a while back -- My Blackstone analyses on my Hondas always read high for copper with the "comment" that it's "probably from a previous fill" although one of these cars hasn't seen anything but Mobil-1 for over 50K miles. Others seem to have gotten the same sort of message. "High copper" just seems to be a common theme with Blackstone. Have no idea why.
-- Don

obyone

where the high copper reading was coming from cause its certainly not the oil.

PAman

So, in that spirit of "my dog is better than your dog," here's some interesting reading about Toyota engines:

http://www.autonews.com/article.cms?articleId=38302

Are you Dodge boys feeling left out? No prob; you have a web forum all your own to discuss your numerous problems. Here 'tis:

http://www.allpar.com/cgi-bin/ub/ultimatebb.cgi?ubb=forum&f=6

Awww...Ford diesel owners suddenly get very quiet about their coolant loss problems? Let's not leave them out--they also have their own support group:

http://www.interstat.net/ford/

Now, if you Dodge and Toyota boys and girls will now quietly leave along with your 'perfect' trucks that NEVER break, maybe this forum can get back to helping people with their Chevy and GMC trucks!

quadrunner500

Copper could come from gaskets, gasket sealants, oil pressure sensor, and pennies left in your oil pan.

rayt2

Pennies left in the oil pan??? Dare I ask?

Ray T.

obyone

Pitch a couple of pennies in there for good luck!!

everhart

remember when they found pop cans in the Vetts gas tanks. He11 we used to put a pebble in the hubcap of the neighbor's car just to drive him crazy, it took him over a year to figure what the noise was.

zr2rando

I have no idea what all is in normal fuel additives, could copper be coming from fuel residue?

rayt2

I can't send you e-mail because it comes back as undeliverable, probably something to do with the screening of all e-mails the State is doing in Albany thru the server.
So could the both of you try e-mailing me the particulars of your extended warranty GM gave you related to the "knock" issue. Or fax me the info at home 845-462-6297

Thanks..........Ray T.

ryanbab

thanks for reminding me. Ill email that now

Ryan

ryanbab

sent all the info. I put it in a word document

rayt2

Thanks, got both the fax and word document. You have provided the ammunition I need to state my case. Will keep you advised as to outcome.

Thanks again.......

Ray T.

rayt2

Now have a case number with GM Customer Assistance related to the infamous "knock". They have arranged for a conference call w/dealer service manager (who had already went home at 3:30 today) for Friday.

Ryan & Martin, you'll be happy to know I mentioned your correspondance related to an extended warranty after 3/36 runs out and the rep said that is what GM has been doing in most of these cases.
To Be Continued..............

Ray T.

ryanbab

got my letter in the mail today. All i have to do is show the letter to the dealership if i have any problems after the 36K warranty

obyone

You mean you didn't receive an imprinted card almost like a credit card? One that you could take anywhere to any dealer? No id number like an account number? Hmmmm I guess a letter is as good as the paper its written on. Who signed the letter?

ryanbab

the letter has a request number at the top. Letter tells dealer to call customer assistance for conformation and authorization

it is signed also

obyone

Not that its important. Cause GM is soooo big any one or their mother could sign it. I'm curious to know what kind of extended warranty comes in the form of a letter as I've never seen one of those before. Got a scanner?

edetor

I also got a "component warranty" from GM Customer Service for 5yr/100k for my engine. It is a letter with a file number at the top and the VIN# in the body of the letter. It explains what is covered:
engine block, cyl heads, intake&exhaust manifolds, all internal engine components, valve covers, eng. oil pan, timing gear cover, eng. oil pump/oil pump housing, eng. seals and eng. gaskets.

It states to keep letter with the truck and that the service Mgr should contact Chev Cust. Assistance for confirmation and authorization of a claim.

I later contacted the BBB and got a 6 yr/100k value guard zero ded. warranty.

ryanbab

Check your email itll be coming soon

obyone

Why did you contact BBB? Were you not satisfied with the letter?

ryan-
so you did get a scanner after all...hehe

ryanbab

yea i got one in december. I use it to scan in things (pics and data tables) for my labs. Works great

edetor

I contacted the BBB because about 1K miles after the new engine was installed I had a transmission leak so I wanted an extended warranty to cover the eng & trans. With about 6k on the new engine still no cold start knock.

roger350

You got a new engine out of the deal? When, and how many miles were on the old one? I thought GM was forbidding dealers from replacing engines because the design hasn't been fixed? What did you have to go through to get the engine replaced? Thanks.

rayt2

to do a decarboning on my 5.3, I said forget it because I have proof from other owners that it does not eliminate the knock and it comes back. She then said they would offer me a 5/75 extended componet warranty. I told her I keep my trucks on average 10 years and would rather have a 6/100,000 ext. warranty. She made a note in my file and I will be called back on Monday regarding my request. Now to go back thru the posts with those who have had the decarboning done and print them out for ammo.

Ray T.

rayt2

Can you scan it & post here or email a copy to me, more ammo for the gunfight at the GM Corral. hehe

Ray T.

ryanbab

check you email

kg11

I took my '01 Sierra 8.1/Allison 4x4 to the dealer today for the knocking prob.(I think it's the same ,sounds like low oil pressure for 30-40 sec on start up)I told the service writer it needs to sit for an hour or two,or it don't do it.When I went back after 1 3/4 hrs he told me a GM engineer would be here on the 26th and scheduled me to bring it back.My lawyer told me to try to get results on my own before giving him money for what GM should be willing to do.It looks to me like the're trying to wait past the one year lemon law deadline.I've only got a few weeks left.
kip