HybridKOOP

Good evening...

So I just purchased a '93 Civic EX to use as a project car; however I need it as my daily driver for a few months.

I noticed an odd noise as I drove the car home from the sellers place. It clanks/rattles from somewhere in the engine bay under acceleration. The noise is loudest at partial throttle, lower rpm range.

To test it out, I first revved the car as it was stationary = NO noise.
I then put the car on jackstands, put it in gear, and gave it throttle = NO noise.

I changed the oil, drove the car, and the noise is there and is consistent. It seems like the noise is louder under a heavier load on the motor. I would think this was detonation, but on a bone stock motor with good gasoline, I don't think this would be possible. Does anyone have ANY idea what I should look into? Keep in mind, the noise DOES NOT OCCUR unless the car is physically in gear and is driving with THROTTLE. It does not happen when coasting, deaccelerating, or idle. Thanks.

Combustion Contraption

Ping.

HybridKOOP

Are you inferring that what I'm experiencing is detonation?

slomofo

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HybridKOOP &raquo;</TD></TR><TR><TD CLASS="quote">Good evening...

So I just purchased a '93 Civic EX to use as a project car; however I need it as my daily driver for a few months.

I noticed an odd noise as I drove the car home from the sellers place. It clanks/rattles from somewhere in the engine bay under acceleration. The noise is loudest at partial throttle, lower rpm range.

To test it out, I first revved the car as it was stationary = NO noise.
I then put the car on jackstands, put it in gear, and gave it throttle = NO noise.

I changed the oil, drove the car, and the noise is there and is consistent. It seems like the noise is louder under a heavier load on the motor. I would think this was detonation, but on a bone stock motor with good gasoline, I don't think this would be possible. Does anyone have ANY idea what I should look into? Keep in mind, the noise DOES NOT OCCUR unless the car is physically in gear and is driving with THROTTLE. It does not happen when coasting, deaccelerating, or idle. Thanks. </TD></TR></TABLE>

Might not be an engine noise then. Check bushings in motor mounts, sway bar end links, and lower control arms.

HybridKOOP

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slomofo &raquo;</TD></TR><TR><TD CLASS="quote">

Might not be an engine noise then. Check bushings in motor mounts, sway bar end links, and lower control arms.</TD></TR></TABLE>

I understand your logic, but I would definitely think that if it was suspension related, it would do it more often than just when the car accelerates. The car stops making the noise the split second that you let off the gas. The noise seems to dissapate toward higher RPM.

Combustion Contraption

Yes, it is also referred to as knock, rattle, detonation and oh ****.

Your only experiencing with the vehicle is moving because the engine is under a load, you cant hear it too much as the RPM increases for 2 reasons.. 1) the mixture gets richer and gets rid of it, and 2) the engine gets louder muffling the knock.

HybridKOOP

Well guys, I went out on a limb and turned the distributor all the way forward to fuly retard the timing... and the noise went away!

I just removed the valve cover. Apparently the idiot who replaced the timing belt has it at least a tooth or two off, which was advancing the ignition timing by God knows what.

As soon as I can figure out TDC on a SOHC (I am a DOHC junky) I will decipher how many teeth this thing was off by. I'm surprised the motor is still in one piece!

Thanks!