2001 gmc pick-up

[flashback]

Re: 2001 gmc pick-up

SBN: I put a couple of those TSB numbers into google and came up with a whole website related to this problem, apparently it is very wide spred. Ill try and post a link to it if anyone else is interested in looking at it pistonslap.com

 

[kenimpzoom]

Re: 2001 gmc pick-up

Piston Slap for the first minute or so when engine is cold is perfectly normal.<br /><br />The pistons are made from different material than the cylinder block. They size the pistons to fit perfectly when the engine is warmed up, so the pistons will be loose when engine is cold. Loose pistons = piston slap = noise.<br /><br />Ken

 

[kenimpzoom]

Re: 2001 gmc pick-up

Originally posted by flashback:<br />SBN: I put a couple of those TSB numbers into google and came up with a whole website related to this problem, apparently it is very wide spred. Ill try and post a link to it if anyone else is interested in looking at it pistonslap.com

Cmon guys, didnt you notice this website is sponsored by LAWYERS!!!!! They only want yours and GMs money!!!!<br /><br />Ken

 

[bh357]

Re: 2001 gmc pick-up

Yep, the lawyers are sniffing around:<br /><br /> http://www.freep.com/money/autonews/knock21_20040221.htm

 

[dhammann]

Re: 2001 gmc pick-up

Yes, it is Greedy, low down, scumbag lawyers...switch to a web-site with accurate technical information....I run like hell when I smell a lawyer. GM has used this same basic design since 1955 with very few changes. It is a proven, reliable design and has been for almost 50 years, you lawyers had to wait this long to make a case? What kind of evidence is that!!!<br />I guess they will be jumping on noisy diesel engines next.<br />I would like to tie a lawyers ankles to a crankshaft and spin him at 1000 rpm on a cold morning and see if he makes any noise!

 

[JoeW]

Re: 2001 gmc pick-up

Very interesting topic. I'd never heard of the problem before. The website was very interesting.

 

[flashback]

Re: 2001 gmc pick-up

well guys, lawyers or no lawyers, I have had a lot of cars and trucks in my life, but this is the first one I ever had which audible piston slap was normal and acceptable, but like I said, I just want to get 150 200 thou out of it. if it will do that then I don't care if it slaps or not.

 

[FLATHEAD]

Re: 2001 gmc pick-up

You will never convince me that piston slap is normall. I guess when you build up one of these babies you set it up with just the right amount and duration of piston slap,,,If it dont slap quite enough just hone er out for a while,, that ought to do it. Give me a break!

 

[DJ]

Re: 2001 gmc pick-up

COLD-piston noise can be quite normal. Metals warm up at different rates. With todays lightweight engine designs, noises become more noticeable. WARM-piston slap, I have a problem with.<br /><br />Believe me, we never heard the ruckus in a 700 pound engine of yesteryear. Todays engines are THIN-by design. Don't let anyone tell you that foreign car engines have no noise.<br /><br />Some of the noisiest engines ever built, and most durable, were the Ford 300 six and the Toyota 22R.<br /><br />I get to hear both crank up, when I walk in the morning, in my neighborhood. The Ford has the Yota beat by 180K-though. (Ford 320K, Yota 140K)<br /><br />The most important aspect of engine life is to look at oil consumption. The Ford, I speak of runs 5W-30 (in AZ heat) and has no issues. The Yota runs 10W-40.<br /><br />If oil consumption is OK, don't worry about it! Also remeber that, oil viscosity has nothing to do with it either. Run what the manufacturer recommends.

 

[SpinnerBait_Nut]

Re: 2001 gmc pick-up

I'm with you Flahthead. There ain't nothing good about piston slap in any engine.<br />Someone said something about putting the pistons in when the engine was warm and that is what made them slap.<br />Uhhh, how do you do that?<br />All the pistons I have ever put in were in a cold block.<br />Do you heat the block with a space heater or what.<br />The only rattle I want to hear is when I start my 7.3 or 6.5 up.

 

[one more cast]

Re: 2001 gmc pick-up

I agree that this is not normal in a healthy engine but it is a common gm problem and in my search found that gm has replaced alot of pistons due to it. I owned a new '92 s-10 for 10 years and it was (and still is) a great little truck. I know own a new 2002 silverado that is really lacking in the quality dept. I am now seriously considering buying a toyota. The fuel usage on fords and dodges is just too much for my income.

 

[SpinnerBait_Nut]

Re: 2001 gmc pick-up

Originally posted by One More Cast:<br />I agree that this is not normal in a healthy engine but it is a common gm problem and in my search found that gm has replaced alot of pistons due to it.

'nuff said.

 

[flashback]

Re: 2001 gmc pick-up

well, if i want new pistons in this beast I guess Ill have to put them in myself, cause the dealership said under no circumstances would they do ANYTHIING about it...one more cast, I too own a 91 S-10 which I gave to my son when I got the gmc, still running good after 175000 miles.. well I guess summer's coming so I won't have to worry about it until next winter... hey i wonder if these new vortec engines do the same thing in boats?????????

 

[one more cast]

Re: 2001 gmc pick-up

Originally posted by flashback:<br />... hey i wonder if these new vortec engines do the same thing in boats?????????

The answer (according to my search) is YES.

 

[dhammann]

Re: 2001 gmc pick-up

Piston slap is caused by the skirt or lower portion of the piston hitting the cyl wall. The piston's centerline is balanced on the wrist pin of the connecting rod and since all the rings are<br />above the center axis it does;nt take much torsional force to rock the piston...factor in the fact that cold stiff oil is laying only on one side of the cylinder(after draining all night) and you can see that the combustion down force is not symetrical. The slap is below ring travel and since the piston and block are disimiliar metal the wear is negible. All engines have some degree of slap but the noise is masked by various factors...believe me, if this was a manufactures deffect we would hear it all over the news.

 

[LubeDude]

Re: 2001 gmc pick-up

Is it normal? For some of GMs engines yes!<br /><br />Is it right? Not to an experienced engine builder, but With this design, Its the nature of the beast. They used this design to reduce friction along with light tention rings!<br /><br />Will it cause problems? NO!<br /><br />Is it irritating? YES!<br /><br />Id switch to a 15W-40 long life or diesel oil at the next change, It will help some!

 

[petryshyn]

Re: 2001 gmc pick-up

Id switch to a 15W-40 long life or diesel oil at the next change

Be careful on the oil recommendation. 15W40 is awful heavy and will cause premature cam and bearing wear in sub zero temps....

 

[LubeDude]

Re: 2001 gmc pick-up

Schematic:<br /><br />Look where he is from! Im sure they are above sub Zero!!!

 

[flashback]

Re: 2001 gmc pick-up

Yea, It did't get below 25 degrees F. all winter here. and when it does it is just overnight...and like i mentioned before, it only rattles if the temp is 35 degrees or less...anyway it was 50 this morning and they say 68 this afternoon so I'm good until next year... LubeDude, would the 15-40w be good for summer? I would guess it would. Thanks to you all for the insights and opinions expressed here, much appriciated...

 

[LubeDude]

Re: 2001 gmc pick-up

Yes, run it all year long. If you use the dello 400 you can easily go 5,000-7,500 miles between changes, It has an awsome aditive package. You might want to go just 3,500 for the first change though as it has a very high detergency and will really clean out your engine. Its a little more expensive, about $1.80 a quart but you can make up the cost by using a wallMart Super Tech oil filter for $1.97. No joke, they are a better filter than a Fram. I sure would try it, Let us know how it works out if you do!