Piston slap

Tleg93 · Post by **Tleg93** » Sun May 08, 2005 5:01 pm

My car recently started making a deep metallic banging noise. It's not the valves to the best of my knowledge. I'm hoping that the pistons aren't slamming up against the heads. Any other ideas on what this could be?

evolutionmovement · Post by **evolutionmovement** » Sun May 08, 2005 5:48 pm

Rod bearings? Piston slap is when the pistons turn with the wrist pin as a pivot in the bore and the skirt hits the cylinder. If something caused them to hit the heads I can't imagine it would run long at all.

Steve

legacy92ej22t · Post by **legacy92ej22t** » Sun May 08, 2005 6:31 pm

I think that was a typo and he meant the cylider walls.

I heard it a little the other day and it did sound like a mild slap. Could just be a miss too caused from a bad plug or plug wire (I hope) but Scott said it gets louder then when I heard it.

vrg3 · Post by **vrg3** » Sun May 08, 2005 7:29 pm

Definitely not valve lifter clatter or anything?

Tleg93 · Post by **Tleg93** » Sun May 08, 2005 7:33 pm

No, it's not vavle clatter, it's a deeper tone. My car engine sounds like a diesel when it gets hot.

I don't know my terminology very well but I was trying to describe what Steve did in better detail.

evolutionmovement · Post by **evolutionmovement** » Sun May 08, 2005 7:51 pm

How does it run? Is it down on power? Really rough?

Steve

Tleg93 · Post by **Tleg93** » Mon May 09, 2005 12:02 am

It has an erratic idle and sometimes it runs weak if I get on it but other than that noting really out of the ordinary. The idle can be pretty unstable at times and it seems like it might stall but it doesn't. Most of the time it's pretty strong.

evolutionmovement · Post by **evolutionmovement** » Mon May 09, 2005 6:12 am

How old are the wires? Really bad misfires can make it sound like it's coming unglued. First time I washed the engine bay I thought I did some serious damage.

Steve

Tleg93 · Post by **Tleg93** » Mon May 09, 2005 12:52 pm

The wires are relatively new. I bought some new ones and replaced the plugs this weekend. There's a couple other issues that may need looked at too first.

Tleg93 · Post by **Tleg93** » Mon May 09, 2005 12:53 pm

vrg3 · Post by **vrg3** » Mon May 09, 2005 4:04 pm

Yeah, a lot of those cheap third-party plug wires for our cars have 90-degree bends at the coil pack side. Some of them have bends on all four wires, and some have bends on two of the four. In any case, you can still use them.

They're not very good wires to begin with, though... It's almost not worth buying any wires other than Magnecors.

TDGKORN · Post by **TDGKORN** » Mon May 09, 2005 4:05 pm

auto or manual

If auto it could be your flexplate. Mine sounded like a diesel when mine broke.

Troy

Tleg93 · Post by **Tleg93** » Mon May 09, 2005 7:10 pm

Flex plate!! My gut is telling me that's a strong possibility. The previous owner replaced the flex plate after the owner before him tried to put a WRX tranny in, IIRC. Now, I'm not too knowledgeable about this stuff at this point so feel free to correct me. So maybe there's an ongoing issue there. After I listened to the noise for a while the other day I noticed that it seemed to travel around the engine so I don't think it's a problem with any one cylinder.

tris91ricer · Post by **tris91ricer** » Mon May 09, 2005 8:23 pm

My flexplate is pretty noisy, too.. I'mma just wait until it goes out again so I can be all bummed about it, though..can't afford the downtime and there's no one to help me, anyway.
But if you've got the time and space, pull that sucker out.

Tleg93 · Post by **Tleg93** » Mon May 09, 2005 9:25 pm

Is there a way to check this without a complete tear down.

TDGKORN · Post by **TDGKORN** » Mon May 09, 2005 9:45 pm

there is an inspection hole down and to the left of the throttle body. There may be a rubber plug in it. If you look down in there with a light and rotate the front crank bolt, you may be able to see a crack (I could when mine broke).

Troy

Tleg93 · Post by **Tleg93** » Tue May 10, 2005 1:17 am

Thanks man, I'll get right on it.

Tleg93 · Post by **Tleg93** » Tue May 10, 2005 3:08 am

vrg3 wrote:Yeah, a lot of those cheap third-party plug wires for our cars have 90-degree bends at the coil pack side. Some of them have bends on all four wires, and some have bends on two of the four. In any case, you can still use them.

They're not very good wires to begin with, though... It's almost not worth buying any wires other than Magnecors.

Yeah, I should buy some magnecores. They didn't have them at advanced so I just got the cheap ones for the sake of testing.

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Piston slap

Piston slap