NISTECH, Horrible engine/transmission noise. Please help

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SlowBack
Posts: 62
Joined: Sun May 29, 2005 6:12 am
Car: 240sx

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Hey, thanks for your help in the other thread. I got the transmission back in with the pilot bushing and I found that the throwout bearing retainer ring was the reason for the noise that I originally dropped the transmission to find.

Here's the new problem:

After driving great for a day and a half, I'm getting what sounds to be (although I hope to god it's not) a rod knock.

It occurs at idle and up to around 2k rpm and then seems to disappear until deceleration.

The transmission shakes horribly as does the engine, but the idle is smooth.

Depressing the clutch pedal makes a swoosh type sound.

I've recorded the sound I'm getting and it can be found here: sound clip


NISTECH
Posts: 10585
Joined: Sun May 25, 2003 4:17 am

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Sounds to inconsistant to be a rod knock. Are you 100 percent sure you tightened the pressure plate bolts back down properly?

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centralcoaster33
Posts: 2634
Joined: Tue Apr 05, 2005 10:41 am
Car: 1997 Nissan 240SX #5
Location: Central Coast, CA

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Hey, so I was on the NICO site searching for someone who’s had the transmission problem I have. I found your sound clip and can say I hear the same noises coming from the bellhousing area of my car. What was your problem and how did you fix it? I found the sound goes away if I just leave it in neutral and depress the clutch. When it’s in idle with the clutch closed, the noise is faint. When I put it in gear and drive the knocking gets horribly loud and now a squeal has added to the fun.

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rogoman
Posts: 848
Joined: Fri Feb 17, 2006 5:44 pm
Car: 1991 240SX FB
2012 Altima 2.5 S

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I'll agree with NISTECH, it does not sound at all like a rod/main bearing knock. A rod bearing knock makes a loud metallic sound; a main bearing knock makes a dull metallic sound.

Since you had the clutch apart, you may not have torqued the bolts down; if so, do it ASAP or else things can come apart dangerously at high RPMs; a good way to lose your leg.

SlowBack
Posts: 62
Joined: Sun May 29, 2005 6:12 am
Car: 240sx

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Haven't been on here in a while and I'm surprised to see this thread is active. It turned out that the flywheel bolts weren't torqued down enough and they began backing out. The noise came from the clutch disc hitting one of the bolts. I hope that helps.

Matt

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rogoman
Posts: 848
Joined: Fri Feb 17, 2006 5:44 pm
Car: 1991 240SX FB
2012 Altima 2.5 S

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Good show! Glad you fixed it right away.


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