Piston slap on a relatively new engine (10K)

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How dangerous in y'alls opinion piston slap is? How bad long term is it for vehicle? Is it normally getting worse as the engine ages? sow much controversy info out there....

What I'm experiencing is a piston slap on a new car with only 10K miles. It doesn't use oil, drives just fine but makes this darn knock/slap up until gets warm. It is very annoying and discouraging. I'm not planning to keep the car forever (perhaps 4-5 years) but really concerned if down the road it gets worse and likely will affect it's sale/trade in value.

So, folks and gals out there with pistons slapping, what would would y'all? live with it? dump it and get a different car? To BE or NOT TO BE???
 
What engine? I've heard a few that had it pretty bad (one of our salesmen's 3.4 Venture minivan comes to mind) but still made 150K without further problems-but if I had a NEW car or truck doing it, the manufacturer would be doing something about it. And here in Ohio, they get 3 chances in the first year, or the Lemon Law means they're buying it back!
 
Currently second attempt to present this to the Honda Dealership is in progress. Again, this afternoon they were unable to duplicate it. Tomorrow morning I'll be there myself with the shop foreman demonstrating. With that being said, even if they finally hear it, I'm 99% confident the answer will be as usual - this is normal. Regardless of what I think about, how bad piston slap is? as far as I understand and see the issue, piston slap is not something that can be simply re-paired. The only solution would be engine swap??
 
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I'd be very unhappy if my new engine had piston slap. To me a demonstrates too much clearance between piston and cylinder wall. Might be injectors in a DI engine though and that noise is normal. Ed
 
That is exactly how I feel about it. and yes, piston skirts slapping cylinder walls doesn't make me feel any better.

I wonder if UOA at this early milage will show any signs of excessive wear due to piston slap?
 
Originally Posted By: parshisa
Currently second attempt to present this to the Honda Dealership is in progress. Again, this afternoon they were unable to duplicate it. Tomorrow morning I'll be there myself with the shop foreman demonstrating. With that being said, even if they finally hear it, I'm 99% confident the answer will be as usual - this is normal. Regardless of what I think about, how bad piston slap is? as far as I understand and see the issue, piston slap is not something that can be simply re-paired. The only solution would be engine swap??


We try to get customers to leave vehicles overnight for issues with cold start up like yours. Brand new Hemi's on the lot sound like they are full of hammers from the lifters leaking down. When I worked at a GMC dealer we had an Envoy come in brand new off of the truck that had piston slap. They didn't want us to tear into it, just replace the engine. We suspected that that one had a piston installed backward.

It is hard to say how bad a little piston slap is at idle, it could run forever like that. It doesn't really matter, if there is a problem it should be repaired under warranty. How long is your warranty? You still have a while to get it fixed, if they can't duplicate it right now. Some times you just have to let things get worse before they can be properly diagnosed, without doing exploratory surgery on it.
 
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Maybe try a thicker oil? My 2nd 3000GT I had would do this on synthetic oil (Castrol Syntec) but not on dino.
 
First of all, I'd like to thank you all for the replies. Glad this forum exists.

To answer your question, there's still plenty left on the warranty - the car is only 1yr old with 10K miles on it (warranty is up to 5yr/80K - honda care). But just dealing with this kind off issues is so annoying. Talking to the service advisors that have close to 0 interest in your problem, techs that could care even less, wasting the time on the trips to dealership, looks of your family members and friends when you tell them there's something wrong with the car...it all is very very disappointing. My dad always care about the cars and I'm the same way. Perhaps a bit more than I should but that's the way I am...
 
Nevertheless, does anyone had experience with piston slap in your car for extended period of times (say few years)??
 
Forged pistons with .0045" clearance will have an audible knocking sound when cold. For that reason, some people do not like forged pistons.
A cast piston fitted @ .0025" is quiet when the engine is cold. If a cast piston is fitted on the loose side, it will never quieten down when the engine warms up.
I would rather have an engine on the loose side, so if overheated or worked hard, won't seize or squeak to a stop.
 
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Originally Posted By: parshisa
Nevertheless, does anyone had experience with piston slap in your car for extended period of times (say few years)??


I've got a '96 Jeep Cherokee/4.0 with a lot of piston slap at first start up. It's done it for years and goes away in about 30 seconds. It's not lifter noise, as the noise is loud when you accelerate, but there is no noise when you coast, again, all noise disappears quickly while the engine warms up. Unlike your vehicle, my Jeep is close to 300K miles. I keep waiting for the infamous Jeep problem where the piston and rod puts a hole in the block, but it keeps living on.
Keep letting the dealer know of your problem, at least you then have it documented.
 
Well, i wouldn't be discouraged at all if my engine at 300K would make a little bit of a piston slap.
smile.gif
lol

But obviously not with 10k only...actually not even 10K - 9393...ughhhh
 
You should post a video of a cold morning startup. Place your camera in the engine bay,hit record,and then start her up.
 
Thanks for the video! I can definitely hear something. When my 3000GT would slap,it'd only do it for maybe 2-3 seconds on cold mornings,first start of the day. Any other starts throughout the day no matter how long she sat,would never be noisy. I'm guessing the oil just completely drained back into the pan overnight. As it's been said,synthetics aren't as polar as dinos (except for esters) and with dino,there would be no cold morning slap at all. It's weird that your slapping sticks around that long after startup. What do cold morning first startups sound like?
 
Well, in fact, what you heard is the cold start. Opposite to yours, first minute or so it sounds fine. not so much right after.

Mobil 0w20 AFE is in engine right now. But engine would do the same even with factory fill and first dealer synthetic blend change.
 
Originally Posted By: parshisa
Currently second attempt to present this to the Honda Dealership is in progress. Again, this afternoon they were unable to duplicate it. Tomorrow morning I'll be there myself with the shop foreman demonstrating. With that being said, even if they finally hear it, I'm 99% confident the answer will be as usual - this is normal. Regardless of what I think about, how bad piston slap is? as far as I understand and see the issue, piston slap is not something that can be simply re-paired. The only solution would be engine swap??


That is Honda's favorite line. Can not duplicate.
I heard that nonsense for years.
Your vehicle sounds awful.
You can always try another dealer or call corporate.
 
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