Anyone know what causes this?

It happens once in awhile If I am engaging the clutch while driving, and if Im not paying attention and let the RPM's fall too low, the engine will knock and sputter a bit untill I give it more gas to get going..... sounds pretty bad, so I try and avoid it as much as possible.

I also heard it again today while seafoaming, I had the PCV valve off and the RPM's were fluctuating and at some points I had allot of seafoam going in and the RPM's dropped very low, so low that it did that knock again, weird...

 

Time for a new motor

 

i wouldn't go as far as saying he needs a new motor.I think when a car is about to stall it usually knocks, right? Is you're timing off? or to keep the rpms from falling play with the idle screw adjuster.

 

Yeah I have heard other cars knock when they idle too low, and about to stall. I did a search on google and found a few tidbits of info saying it is related to pre-ignition I think that causes the knock at very low rpm (correct me if im wrong).

It runs fine any other time, I guess i just let it idle down to low under load (letting it sip the seafoam, did not let it hydrolock)

 

Timing isn't off I don't believe. I definately need to adjust my idle though, it goes down too low when I let off the throttle then chokes and goes back up to around 650-700 rpm again.

 

A motor pings, not knocks when about to stall.... Two really different sounds... But he did say KNOCK

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cottonwoodz &raquo;</TD></TR><TR><TD CLASS="quote">A motor pings, not knocks when about to stall.... Two really different sounds... But he did say KNOCK </TD></TR></TABLE>

yeah....if a motor knocks at any rpm you've got problems

 

it was probably pinging then. I havn't heard the difference between a loud knocking motor and a pinging one, but i was just trying to describe the sound, it was subtle, nothing that really drew attention from neighbours or anything :D

 

does it sound like you have a bunch of rocks in your engine?


id check your O2 sensor and wiring. because if the ecu is getting a bad a/fr from the O2 sensor its throwing off your timing to compensate... check your CEL





Modified by honda head at 2:58 PM 10/3/2006

 

tighten up that throttle cable too, so there is no slack.

 

yes it sounds very familiar to rocks in the engine, but it wasn't RPM dependant, if i revved it up there was no sound, just happend that 2 times when it was about to stall.

Will tightening up my throttle cable stop the enging from dipping to low when coming off throttle?

I have this side issue that when Im driving, sometimes when I let off the gas and in neutral (at a stop light etc, the RPM will drop down to about 200rpm then after a sec or so jump back up to aroun 75p rom again.


Or is this something very different.

 

is this a forth gen prelude?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by loudsubz &raquo;</TD></TR><TR><TD CLASS="quote">Will tightening up my throttle cable stop the enging from dipping to low when coming off throttle?.</TD></TR></TABLE>

try the throttle body idle screw

 

97 5th gen h22a4