Recalls & Engine Knock Info

[vtx1300]

wondering if anyone out here has heard of this? I have a 2001 2500 Silverado
aproximatly 95000 mls on it allways keep up with oil changes never abuse my truck. The other day I had a valve spring break it drop down into the cylinder and desstroyed my engine my mechanic jus found me another engine gonna cost me about 3,500.00 to get it fixed . ive had the vehicle about 7 months no warranty. Wish the **** I found this forum before I bought the truck.

[johndeerrm]

Originally Posted by vtx1300

wondering if anyone out here has heard of this? I have a 2001 2500 Silverado
aproximatly 95000 mls on it allways keep up with oil changes never abuse my truck. The other day I had a valve spring break it drop down into the cylinder and desstroyed my engine my mechanic jus found me another engine gonna cost me about 3,500.00 to get it fixed . ive had the vehicle about 7 months no warranty. Wish the **** I found this forum before I bought the truck.

Are you suggesting that piston slap caused your valvespring to break?

[chevygator]

I just recently purchased a 00 chevy silverado and adter getting it home, the next day on a cold start it pings! I feel sure the dealer made sure it was cranked before anyone drove it....... anyway my question is I see a lot of postings about this but.... has anyones truck stopped running due to this or is it just irratating??

thanks - I am new to this so help me out here!

[mntahoe]

Not that I've heard of. I still want to hear from someone who has lifted the heads off of a "pinger" and tell me if some or all of the pistons are in backwards. Other than engines with forged pistons (which also burn oil when cold due to excessive ring clearance when cold) every motor I've known to do this had the pistons in backwards.

[russo_z]

In most cases it is a Carbon build up...you can purchase cleaners at your local store for cheap...if problem remains then you should begin to worry.

Zach Russo
Automotive Editor
www.reply.com

[truebluegrass]

I'm brand spankin' new to the Chevy forum. I'm sure relieved to hear that everyone else is suffering from Chevy carbon/piston slap, too. Mine is a 2004 2500HD with a 6 liter, and the noise started at about 20K miles. It was irritating the snot out of me, and had me wondering why I bought a Chevy when there were so many nice Super Duty Fords out there that don't make that noise. I took it to the local Chevy dealer, and he said he couldn't hear anything, even when cold. So I immediately took it to another Chevy dealer in the KC, MO area, who actually had ears and a better attitude, who gave me a copy of the tech bulletin describing the problem. I'm glad to hear about the extended warranty thing, I'm going to try that.

I've tried Seafoam, but it doesn't seem to help. I hate to pay for higher octane, but I think I'll give it a try, anyway.

When I bought the truck I also bought a Chevy Trucks black/gold hat, but I don't wear it much after that stinking noise started. The engine has plenty of power and runs smooth, but it's awful embarrassing to a former Ford owner to be in a knocking Chevy.

Everything else on the truck is GREAT! I just have to turn up the Bose speakers to cover up the dreaded GM engine knock, 'cause it's hard to keep the engine RPM's up to the same speed as my bluegrass music on the XM!

[Back Woods]

Engine knock?

Caused by the hydraulic lifters when first started?

My dads 02 seirra 6.0 did this. It was still in warrenty so he took it in and the put a 2003 engine in it for free. Aluminum heads, it was alot nicer. But the truck only got 8mpg.

[koltrain]

I am new here and I work at a shop. I drive a 92 GMC C1500 and started to get engine knock. It also triggered my sevice engine soon light. So I hook it up on the scanner and it says I have a ECS failure. Do any of you guys know what the problem is?

[koltrain]

I'm gonna try and replace the whole ignition system, maybe that'll clear it up!

[02knocker]

look at my user name !
i bought my 2002 silverado 6.0 2500hd used in 04, it had 7,000 miles on it. got a really good deal, [i thought]very nice truck, has alot of power but it has piston slap. it started knocking at about 10,000 miles.still had the warranty when i took it back to the dealer. they said they could here nothing after keeping it over nite. i kept complaining about the noise, then they wanted to change the o-ring in the oil pump, so i played the game, they said it fixed the knock, wrong!still knocking at start up. i called 1-800 gm , 3 way call with dealer, they gave me the ol 100,000 warranty but still would not admit it was piston slap.i was not happy.then they wanted to change the lifters next. why cant they just fix the problem. ilove this truck and want to keep driving it but it wont be worth much when i trade it in some day. currently it has 35,000 miles on it and still knocking at start up. i use mobile 1 syn. chg. every 3-5000 miles. it sounds like a diesel when cold. i see some pepole turn there head when i start it , they know!
i will try the de- carbonize thing but i know what the problem is.i have always bought gm vehicles, nothing else, but this really tics me off that gm would not fix the problem.
i have read and researched piston slap, my truck has it . i hate to sell it to some other poor sole. so what are you supposed to do?

[RandallH1989]

Just wondering if I have the same thing, I have an '03 4.8 and when I start it up in the morning when it is cold, it makes a sound like "tts tts tts tts" (best way I can describe it, but not really a "slap" either). It doesn't sound like it's coming from the engine, and it only does it for a minute or so. Is this what you are referring to on this topic?

[itsachevythang6]

lol lol lol, this is total, bull sh*t, guys, i start my truck (2000 Z71 silverado 5.3L) up every mornin to listen to the wonderful knocking that comes from your (when new) $35,000 truck haha, isn't it great that your favorite car manufacture, built with GM pride is an has put this off for a while now, my truck now with 110k on it, has the annoying deep knock in the morning an when hot it has the tapping sound of a lifter, or valve every once in a while, i tried thicker oil, i even once went to 20W-50 that didn't work, an what i run in it now, is the common 10W-40 with some oil stablizer, put still, you gotta be proud when your out showing off your truck, and you go to start it up in front of a crowd, to hear these noises, does anyone feel the same way? or been in the same boat?

[BIZILL]

i just wait to make sure no one is walking the neighborhood before i leave for work in the morning. very embarassing.

[LS4U2NV]

I have almost 70,000 on my '03 with only a small bit of slap when it's cold. What annoys me is when I let it idle. The Belt squeeks which isn't even really that bad. Louder than the slap.
Another thing I have noticed is when it sits at idle warming up about 10 minutes or so... I hear this hissing noise. Very similar to my brother's 98 Dodge Ram with a 318 in it. He tracked it down to a sensor or whatever it was mounted on his passenger fender well. A co-worker of mine heard it this morning and wondered what it was as well.

Other than what I mentioned above. I have no problems.
I didn't read through all the posts. But I would like to know if anybody running the 4.8, 5.3, or 6.0 engines that are built to run E-85 have experienced any slapping noise. I know some internal components are made of different materials to handle the corrosion problems of E-85. Also. E-85 has a higher Octane rating than the typical gasoline blends.
Any E-85 users wanna chime in? TIA -Matt-

[gyusher]

I wonder what an engine block heater would do for this cold engine knock??? Seems to me that if you could keep it warm enough. . .

[GMC is #1]

I am also new to this site. I have been a long time fan of GM. I have a 99 sierra with aluminum 5.3. It has always done the "Piston slapp" when cold. I have 125000 on the truck now. It always has burnt one quart of oil in between oil changes. I realize that GM does have a defect on their hands. You have to remember though, these engines may be anoying for 5-30 seconds, but last forever and will out pull, out run, and out perform anything else. I am currently only 20 credits away from my mechanical engineering degree, and have done uncountable hours of reserch on this topic of pistion slap. I believe that the problem won't cause any sort of prmature engine failure.(And havn't seen any cases saying "piston slapp" has caused the engine to wear out) finally, the only other symtom would be the small decrease in gas milage. (loss of 1-2mpg) but if you can afford the truck, and afford to fill the 26 or 34 gallon tank then you probably won't notice the slight decreas in mpg. I personly still love GM, and even though they did make a mistake, (Every company does)I will always buy their product. ALWAYS AMERICAN!

[LS1Mike]

I have been reading all the Piston slap stuff, and it really shouldn't be a concern to anyone, I have had 3 LS1s and the 04 Silverado and they all did it. Yeah I don't like how it sounds, but my 98 Z28 was really loud, I put 150,000 miles on it, maybe 40 to 50 15 lbs bottles of n2o through it and 300 1/4 mile passes without any issues. Trucks aren't the only one with the problem, F-bodies and Corvettes do it too. You here it longer in the Aluminum blocked cars too. I never noticed it in the truck as much as the f-bodies I had. The Trans Am sounds like a Cummins when I start it. I get past that though, when I am showing 99% of the cars on the road tailights. It goes away when warmed up.
If you can deal with the noise, I wouldn't worry about it.

When it was happening on the Corvettes if you complained they would pull the motor apart and replace one ring on each piston, I want to say it was the oil one, huge discussion on LS1tech about it, you lose some power because it tightens up the tolerances.
I will take the noise.

[mikwalters]

Hi sounds like I'm not the only one with issues FYI my knock Hammer lasts for 15-30 minutes my 1999 Yukon has cost me around $8k in power train issues I had new lifters for the knock issue installed but nothing changed. If you have a misfire problem a head rebuild fixed mine around $2300 and a grand to get to that point. My transmission went out around 84k reverse goes first with them from what i've learned the 4L60 version, And I never tow anything get that.

[KAPPY]

what about the 5.7?i have a 96 sierra and it knocks in cold starts.what type of oil should i be using?

[roydenv]

the enging knock only exists in cold temps-below 50*-OIL HAS BEEN CHG. REG. 5-30,10-30..NO DIFFERENCE-MINE IS `99 SILVERADO-75K,NEIGHBOR `00 SILV`ADO-SAME PROB.-HAS ONLY BEEN NOTICABLE SINCE 2 YRS OLD-IT`S NOT A CARBON PROBLEM-OIL CIRCULATION PROBLEM-PROOF-START ENG.RUN 15 SEC-SHUT DN. FOR 30 SEC -RE START-NO KNOCK-IF NOT THE KNOCK WILL CONTINUE FOE SEVERAL MINUTES-DEALER SAYS IT`S NORMAL? SOO MANY PEOPLE W/SAME PROBLEM-WHAT CAN WE DO TO FORCE GM TO CORRECT IT!!