EchelonMotors

Hey guys, I have 2 two unknown issues in a 2000 Civic Si I just bought. I wanna see if you guys know what it could be, because they're killing the vibe lol.

#1: Whenever I'm in gear and let go of the throttle, e.g. coasting, I hear this somewhat faint grinding noise; it's not grinding like you'd hear when you accidentally grind a gear, it's more like a consistent "dragging" noise. Almost like something is dragging along or rubbing.

The noise disappears whenever I press down the clutch or accelerate.

I'm sure it isn't the transmission because I just replaced the fluid and there were no signs of metal, and the transmission shifts very smoothly.

#2: When I turn on the A/C and I'm in neutral, the car vibrates noticeably. I noticed the revs go down lower than average - I was told it could be a mount, but why would that affect the RPM?


Thank you in advance to whoever can help her out lol:

grumblemarc

iTrader: (4)

Holy triplicate Batman!
#2 is normal concerning the RPM. Why would it not affect RPMs?

EchelonMotors

Sorry, I don't know what happened haha.

What I mean is that if it were an issue with the mount, it shouldn't affect RPM right?

DcAvery

Correct-a-moundo! It just keeps the motor mounted in place. The mount itself isnt mechanical so it wouldent affect performance. Unless you are missing one and the block is sitting cockeyed.

mithious

#1. I have on both of my civics (93 del sol and 97 CX). I believe it is normal. (you're talking about when you're in neutral with your foot off the clutch right? Very slight metal on metal type rubbing noise? Think flywheel/clutch

#2. (as this was just explained in depth to me...) the air con takes a big electrical draw and places a strain on your engine, hence the RPM drops. Your car normally will compensate for that and bring the RPM's back up. But it takes a few seconds, how long that takes is going to depend on a few different factors. But it's normal.

But when YOUR car idles at this lower RPM, it vibrates badly because you've got a crappy motor mount. It's a very common civic problem that the motor mounts wear out. I have one worn out in my 97 that I haven't gotten around to yet, and I just have to rev it a bit higher when I drive.

You can test this by seeing how the engine vibrates driving at the same RPM. (edit, or just look at the mounts!)

shotoutacc0rd

Put a little pressure on the brakes, rev the engine a little for just a second, if the engine rocks around its the engine mounts. If the car rocks, the engine is mounted well.

its an easy test but you need to be very particular with the pedals you can't touch either of em too hard

Former User

#1 - transmission input shaft/main bearing needs to be replaced

#2 - try cleaning the IACV

eghatch9295

iTrader: (1)

ron nailed it with number one.

EchelonMotors

Thanks guys, this helps a lot.

In regard to the input shaft/main bearing, I looked it up, but the noise shown on other cas is a lot more audible than mine; it's pretty damn loud in the videos I've seen. Could this be that it's not as severe yet?

EchelonMotors

Oh, and I'll try the IACV. Because the RPM go down all the way to about 300...

Former User

^

eghatch9295

iTrader: (1)

itll keep getting worse. unless you have a good spare trans, fix it before it goes.