devgon2

I have 98 Prelude

I recently noticed a strange fast rattling noise the car makes while i'm accelerating and the car is moving. The noise doesn't surface if the car is in park and I just rev the engine.

When I gas forward, it starts rattling. It sounds like it's coming from the left side, but recently i've started hearing it from the like the middle and right side as well (maybe?).

It's more like metal clunking sound....and I can usually hear it around 3K RPM....

I don't think I heard that sound when the engine is cold. Only when its warm.

Anyway, any input on this would be greatly appreciated..

xxmastermindxx

only when you're in motion? loose/rusted exhaust pipes maybe?

devgon2

well i have greddy catback and I tried moving the muffler back and forth and it doesn't make much sound....So i guess loose/rusted exhaust pipes is out of equation.. .?

xxmastermindxx

a while back, i noticed a metallic kind of rattling noise while i was driving, mostly when i would turn hard. i found the problem and it was an exhaust pipe but under the car maybe just past the flex pipe, it was a stock system and it had just rusted loose, so it was banging around.

jack up your car and get a leg under and see if you can move your exhaust back and forth and reproduce your noise.

thiagobr

there is a bracket under ur car, right after the headers and before the flexible, on this bracket theres is a metal piece that goes really close to the oil pan, check it, it may be cracked and they usually slide under the other piece, if you dont see it let me know ill get you a picture of it.

devgon2

^^^
yeh plz post a pic... it will help a lot.
thnx

devgon2

well one of my buddy just checked my ride. According to him its a clutch problem. Something to do with bearing.

Anyways he said the clutch was suppose to get adjusted every 4000K miles or six months which ever comes first.

The guy from which i bought this car had the clutch, timming belt replaced at around 80k miles and now the car has 85K miles on it...

i didnt knw clutch goes bad this fast...only 5k miles...


Modified by devgon2 at 9:37 PM 7/3/2007

tham1ll

if its a knock and it only happens when you increase the load (accelerating) its a fuel knock. it occurs when the fuel injected into one or more cylinders detonates before the piston has completed its motion and fully compressed the air/fuel mixture. the early detonation is called preignition fuel ignites before the spark plug sparks... it is caused when carbon builds up in the cylinder heads... you don't hear it when the car is cold because once the car has warmed up the carbon that has built up in your cylinder gets so hot it glows red causing the fuel to ignite just an instant before the spark plug ignites... raise the octane level of your gas for about six months... higher octane fuels resist early ignition and has more cleaning additives which will help with the carbon build up after six months go back to what you usually use

devgon2

no its not knocking....

here's what my friend has to say about the rattle:
well, from what i was able to gather, under load starting at 2g rpm and up it is a higher pitched rattle, sounding like a release bearing, or pressure plate rattle.

doesn't do it sitting still out of gear, and it does it in all gears, the rattling gets quicker the higher the rev's.

not vehicle speed related, but engine speed related.

tham1ll

ok well a rattling noise means timing system problems... make sure your cam lobes are opening and closing the valves properly (at the right time and make sure they open fully ) check for a bent valve as well. check your timing belt as well hondas usually need a change of timing belts at 90,000 miles because over time the belt stretches and the belt is taught on the right of the pulley and slack on the left... GET IT FIXED ASAP if you break a timing belt on the road your s.o.l. and it can damage the engine (it could lead to bent valves ...)