Is this piston slap?
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
Is this piston slap?
2000 with 89k miles, Seems to be well taken care of.
This noise happens on cold starts, I always give it about 5 min to warm up, and it usually goes away when I start driving. I believe its piston slap, but it seems to pulse, so it makes me think it might be something else? I just got the car 2 days ago, so I'm still learning it.
This noise happens on cold starts, I always give it about 5 min to warm up, and it usually goes away when I start driving. I believe its piston slap, but it seems to pulse, so it makes me think it might be something else? I just got the car 2 days ago, so I'm still learning it.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,670
99% sure it's a piston slap. Mine was worse than yours!! Bought my car in the Summer heat. No noises, 23,000 miles. Late September, 45° outside, started the car-and no exggeration-sounded like a diesel. In 3 or 4 minutes, noise disappeared. I called the GM dealer, and they admitted some '99 and '00 models, maybe even some '01s, had a piston slap, and they told me to bring it in. Once there, they told me it wasn't "commercially unacceptable!" This was all before I joined the forum, so I didn't realize that GM had actually replaced some engines under warranty due to this. Will it hurt anything? Not likely, if it is just a piston slap.
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
99% sure it's a piston slap. Bought my car in the Summer heat. No noises, 23,000 miles. Late September, 45° outside, started the car-and no exggeration-sounded like a diesel. In 3 or 4 minutes, noise disappeared. I called the GM dealer, and they admitted some '99 and '00 models, maybe even some '01s, had a piston slap, and they told me to bring it in. Once there, they told me it wasn't "commercially unacceptable!" This was all before I joined the forum, so I didn't realize that GM had actually replaced some engines under warranty due to this. Will it hurt anything? Not likely, if it is just a piston slap.
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
I replaced the main serpentine belt already, I didn't check the AC one. The harmonic balancer is going bad, so maybe that could be doing it?
Race Director
Joined: Oct 2004
Posts: 12,864
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Sure could be a major contributor!!!! Replace that NOW!! Before it walks its way into the timing cover, and wears thru it......
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
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Burning Brakes
Joined: Jun 2018
Posts: 756
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From: SC
02 has the slap too. Yes, I had forgotten about it in the summer, it quiets right down. Definitely a chirping going on, ac belt, Tensioners... I had my harmonic replaced for about $600. Get it done, dire consequences if it goes all the way out, into the engine front as mentioned or out into the steering wrack.
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
The issue turned out to be something with the AC. The noise gets louder and more consistent when I turn the AC on. Here is my HB at temp, I marked a white line down the entire front on Wednesday. So far, even after 10 or so 6k pulls, it hasn't visibly moved. It is still #1 on my list though.
Instructor
Joined: Feb 2010
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From: Greenville NC
Thread Starter
Instructor
Joined: Aug 2021
Posts: 200
Likes: 34
From: Niceville FL
No, sorry, I was listening on a phone outdoors and could hear what sounded like the ticking / rattling noise (almost like a knock) that is what piston slap sound in a cold car sounds like. the noise that I hear loudest on the computer sounds more like something to do with belt system - belt tensioner, belt, bearing, etc... Sorry