Low RPM rattle? - Honda Prelude Forum

GodFist · 05-16-2008, 12:07 PM

Just bought a 97base prelude roughly 121K. Seems to have a tin-can like rattle on low rpms when in gear(manual). Doesnt make sound at idle. At first i thought that something might have come loose like exhaust or anything but still have yet to find where it comes from. Im starting to suspect something in the driveline. If anyone has suggestions or ideas to what might cause the noise id apreciate it.

hondatune32206 · 05-16-2008, 12:10 PM

Heat shield?

GodFist · 05-16-2008, 12:15 PM

heh took it off for that reason. not it -_-

hondatune32206 · 05-16-2008, 12:16 PM

Exhaust hangers? Where is the rattle coming from?

Artifex · 05-16-2008, 12:23 PM

Does it happen only under load (acceleration)? You might be referring to detonation.

If not, it sounds like you are referring to the autotensioner death rattle.

GodFist · 05-16-2008, 12:46 PM

Yes the rattle only happens under a load or accel. As for where the rattle is coming from it is hard to tell because i must be inside and driving to induce the problem. Noise occurs roughly from 1000-2500rpm

lude4lifeh22 · 05-16-2008, 12:49 PM

My guess is catalytic converter. When those go bad internally, they will rattle between 2500 and 3000 rpms.

Get any Check Engine Lights?

GodFist · 05-16-2008, 12:51 PM

yes acually i have my CEL on for the Cat. below efficiency or w/e. I figure its just an O2 sensor ill have to replace.

lude4lifeh22 · 05-16-2008, 01:32 PM

Quote:

Originally Posted by GodFist

yes acually i have my CEL on for the Cat. below efficiency or w/e. I figure its just an O2 sensor ill have to replace.

With this rattle, Im guessing its the catalytic convert itself. Thats what mine did. Happened only a few months after I bought it too

GodFist · 05-16-2008, 02:59 PM

Yea i have a bunch of issues with this one including small engine surges while cold and a pretty big oil burning problem(1qt:2weeks). Gotta do valve cover gasket and valve seats. I have blowby on top.

lude4lifeh22 · 05-16-2008, 09:17 PM

That amount of oil isnt really too bad. I usually gotta put about a qt in every few weeks. H22's are known for their oil consumption.

Solid · 05-16-2008, 09:19 PM

I would check the exhaust mounts/hangers and check the collector-cat and cat-exhaust. It may be loose and causing a leak which can throw the CEL.

JustXtreme · 05-17-2008, 07:00 AM

I have the same rattle, it's a scary sound. let me know if you get it fixed

sr73087 · 05-21-2008, 06:31 PM

if you have access to a vantage pro or anything you can check the switching rate of the secondary o2 sensor. Thats what its looking for to throw the code. General rule of thumb i believe is 10x per second.

Does anyone know any ways of checking cats ? I remember a way using a vacuum gauge but i forget it exactly.

_BB6 · 05-22-2008, 10:27 PM

Quote:

Originally Posted by Artifex

Does it happen only under load (acceleration)? You might be referring to detonation.

If not, it sounds like you are referring to the autotensioner death rattle.

could you go into details on this. mine sounds similar to his and when you say autotensioner death rattle, that makes my body shiver.. thanks.

turk · 06-13-2008, 08:05 AM

I had the same problem, it only rattles when excelerating from first. When I installed my new exhaust I just hit the Cat with my hand and could hear and feel something ratteling.

Which leads me to ask if anyone knows a good catalytic converter to purchase?