"Piston slap okay" says GM - Maintenance Forum

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"Piston slap okay" says GM
Tuesday, November 30, 2004 9:52 AM

In the past while, we've had some discussions about the noises our Ecotec engines have been making and it has caused concern for some about whether or not their engines are about to blow up!

I mentioned that it sounded like piston slap to me, while others thought it could be the timing chain, valves or injectors. Today I decided to pay a visit to the GM dealer that I bought my Sunfire from and have a talk with the shop foreman. We discussed the pros and cons of the Ecotec engine.

Apparently it is indeed piston slap that we hear when we start a cold engine and especially on acceleration. GM knows about this, according to the shop foreman, but they have no problem with it as long as it goes away when the engine is up to temperature. The cause of the piston slap is a combination of the taper of the piston along with the fact that the skirt length has been shortened a bit to reduce inertia ( this allows for a quicker reving engine). This allows the piston to rock a bit in the cylinder when cold and causes the piston slap that we hear. When the engine gets hot, no problem because of the reduced clearances.

I asked if the timing chain could be contributing to the noise and he said that if there was indeed a timing chain problem, it would sound like someone was standing next to my car door and whacking it with a chain. Fortunately I haven't heard anything like this!!

Apparently the engine by its very design is noisy. The camshafts and valve noise comes up through the aluminium cover and is very easy to hear especially when you have your nose under the hood.

The foreman admitted that these engines are noisy but they have so many good features and are really well desighed overall, so I guess a little noise is something that we can live with.

We both agreed that it would not be the best idea to red line your engine from a cold start, but let it get up to temperature first. lol....

So there you have it fellow Ecoteckies!! Enjoy those cars!!!!

Have a great day......Lionel

Re: "Piston slap okay" says GM
Tuesday, November 30, 2004 12:01 PM
well if its the same thing i hear on mine then ill go tonight before they close and grab my car back... There actually trying to figure out the problem and they cant. They said its not the Timing chain but anything else could be the problem. Even the mechanic said to me that they dont have the certification to work on these Eco's. I was like WTF ?!?!

I hate the car they rent me. Altought i dont pay anything for it, its a god damn ACCENT !!!

Next time ill specify to have a Cavalier or Sunfire....
Re: "Piston slap okay" says GM
Tuesday, November 30, 2004 12:51 PM


"Even the mechanic said to me that they dont have the certification to work on these Eco's"

el, is that garage that has your car a GM dealer? If it's just a repair garage, I can see that their mechanics might not be certified to work on the Ecos and I certainly wouldn't want a garage like that to touch any part of my car!

If that garage of yours is in fact a GM dealer, you had better get yourself and your car down here to Southern Ontario where you can find qualified mechanics. LoL!!

Hope you make out okay........Lionel
Re: "Piston slap okay" says GM
Tuesday, November 30, 2004 2:13 PM
its a dealer GM...

lol sure would but its 8hres from there

anyway they checked it and the sound comes form the Timing Chain. They reported the problem to GM. They dont want to open it cuse the sound fades out when hot. So im just waiting to see this winter if the sound clears out when hot or still stays there. I know 1 of those mechanics that work there and he told me to beat the hell out of it so it can blow up.

Anyway i saw the cobalt with a real engine in it. They had 1 in stock. 4 doors automatic all stock lol. and the gay plastic over the engine is not my style. If you want to change your filter you have to remove it.
Re: "Piston slap okay" says GM
Thursday, December 02, 2004 1:39 PM
I was a little concerned upon first noticing the noise of the Ecotec when it's cold but now that I've heard the same symptoms from so many others, I have concluded that it is just the nature of the motor. At first, I thought the noise didn't disappear when the motor warmed-up but after paying more attention I realize that it is always gone at least by the time the motor has reached full operating temperature.

Therefore, I'm no longer concerned and otherwise hope that the motor lives up to GM's reported expectations. Actually, except for price incentives and the positive information I had read about the 2.2 Ecotec as introduced in 2003, I probably would not have purchased a Cavalier. (I wasn't too trusting, however, as I used some of the savings incentive to purchase additional power train warranty!)
Re: "Piston slap okay" says GM
Friday, December 03, 2004 8:19 AM

To: Spudislander,

I can appreciate the concern you must have felt when you first heard how noisy the engine is when cold. I'm surprised I didn't notice it when I first drove the car from the dealers lot to try it out. Maybe they had already ran it and got the temperature up before I tried it (they knew I was coming). Even after the car sits for awhile after being run, it doesn't make nearly the same noise that it does when it's really cold.

I wouldn't be surprised to see GM redesigning the pistons and going to maybe a different alloy with a different taper and a longer skirt to reduce or eliminate the noise.
It was sort of comical when I first went into the GM dealer a few days ago to talk to the shop foreman about this. He pretended that he hadn't heard any noise from these engines when cold but when he realized that he wasn't going to fool an old mechanic, he opened up to me and we had a good conversation about these engines. As I said in my other post, GM knows very well about the piston slap when cold and the shop foreman said I had no need to be concerned with it unless it didn't go away after the engine was up to temperature.

So far, that is the only complaint I have about the Ecotecs. Other than that, I really like my Sunfire and I enjoy driving it. It's comfortable and it has plenty of power for normal driving. I think my wife would have preferred that I bought one with an automatic transmisson though! ( but that would have taken the fun out of it for me..LoL).

As far as those prices incentives that you mentioned, yes they were really too much to pass up. I actually ended up buying a new 2005 Sunfire for just under $ 10,000! But of course you have to add all the other costs to it like taxes, shipping, admin cost, etc. But it was still one heck of a deal.

I see that you are a fellow Canadian. In what part of Canada do you live?

Have a great day......Lionel
Re: "Piston slap okay" says GM
Wednesday, December 08, 2004 1:15 PM
Hey guys also take into consideration thinner oils and additives ( such as the racing) types will contribute to the start up noise as well...thinner the film the less the "insulation" effect against the clearance...although minimal it is a factor...Cavaliers kick ass!
Re: "Piston slap okay" says GM
Friday, July 15, 2005 10:18 AM
That's would make a good newspaper headline I think.

This is the fourth cavalier I have owned, not to mention the countless other automobiles ranging from point set ignition to the modern amplifier looking thing on my ecotec.

All I can say is this is my best grocery getter by far.

If you do the research, you'll find that you can build it to 250hp with all factory internals. If you have a manual transmission or 3 speed auto you are only limited to 190 lb. ft. of torque if you want the car to last. But if you have a 4 or 5 speed auto (believe it or not the 4 speed takes more of a beating) it only takes one bolt on mod to take out almost everything out there in a drag race.

And the counter balance rods aren't put there to make the engine quiet the way your thinking; this engine is smooth, and it breathes, and it's like it's almost waiting for you to go out there and modify it to max volumetric efficiency (like the GM engineers were holding something back).

If the sounds bug you that much, buy a cat-back exhaust system for the car to drown them out. Cause at least, I know you'll like the way that sounds.
Re: "Piston slap okay" says GM
Friday, August 12, 2005 3:21 PM
i dont know if this will help but here in the united kingdon are 2.2 engines are noisy at start-up mainly cos of the timing chain.the main oil jet that delivers the oil into the chain is of poor design.vauxhall reccomended 20,000 mile oil change intervals,then decided later it needed to be changed every 10,000. as the old oil was blocking up the oil jet,until they introduced a recall to have the better oil jet fitted.......
hope this helps,
im not 100%sure our 2.2 engines are the same as yours are but i think theyll be near enough..
dave.....



Re:
Thursday, December 15, 2005 7:52 PM
the slap is caused by using a eutectic piston, or at least a contributing factor.


Everette Price wrote:But if you have a 4 or 5 speed auto (believe it or not the 4 speed takes more of a beating) it only takes one bolt on mod to take out almost everything out there in a drag race.




you must have some slow cars where you live.
Re:
Sunday, January 08, 2006 5:56 PM
I was noticing this on my mother's 02 ecotec auto cavy today. But as the car warmed it smoothed out. Hers has about 31k mi on it....my 04 cavy 5spd has about 5k and I really don't notice the same noise....still in the wear in period there maybe?

Re:Noisy engine fix for mine
Thursday, November 11, 2010 9:27 PM
My 2002 eco has had this noisy engine for some time , I added this morempg.ca and guys don't hesitate it took the noise out and I re-reated again after 3 oil changes and it's been over 9 months runs extremely quiet and I had that noise before for years, this thing would kind of knock every morning and embarasing sometimes driving along side of a brick building made it apear as it was constant. Anyways Iove what it did for my.
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