2800 rpm vibration/rattle..... - Honda Prelude Forum

Aaron97SH · 02-04-2002, 10:58 PM

Everytime I rev past the 2800-3000 rpm range there is this annoying buzzing rattle coming from under the car.

That must be a loose heat shield, right?

BTW, I have a dc header and a tanabe G-power exhaust.

DragonSI · 02-04-2002, 11:23 PM

I have the same problem I think its the heat shield but not sure, anyone else?

big blue h22 · 02-05-2002, 12:43 AM

I have the same problem, i have dc headers and apexi exhaust, it sounds like a heat shield to me, so the other day I put it up on the rack at the shop and noticed where it was coming from when I got someone to rev it up. It was coming from the inside of that little connection that looks like a basket weave, know what im talkin bout, that bendible sort of piping, right after the headers. this might not be your problem but it was mine, there was no way I could get to the inside of that thing though. sux

Aaron97SH · 02-05-2002, 11:55 AM

I hope that's not what it is on mine. There's no way I'm going to buy a new header to fix that.

Keith · 02-05-2002, 12:24 PM

I have that too... It wasn't the heat shield... it was the timing belt cover rubbing against the time belt... it was an expensive job too and now it's back! What a waste.

Keith

TranceAZN · 02-05-2002, 02:50 PM

i had a rattling noise everytime i decelerate back down to the 2000-3000 rpm range, i had the dealer check it out and said that the noise came from a tension belt so they replaced it for me. (7 hours job they claim). Good thing it was still under warranty.

Joon525 · 02-05-2002, 04:57 PM

Check the header and check the timing belt (area).
I've had both make that noise.

ludethugs · 02-15-2002, 12:11 AM

i get the rattling sound only when i slow down while still in gear. if i rev harder or if i shift to neutral the rattling sound goes away.

i had an N1 exhaust installed a few days ago and this rattling just started this afternoon.

How long does it take to take off the heat shield? and does it cause any problems down the road?

Or better yet, is there a way to fix that rattling without taking off the protective heat shield...
thanks guys

ImagePree · 02-15-2002, 12:20 AM

if you guys have a DC header, it SHOULD be the bracket that bolts the flex pipe to the chassis. most likely, that piece is snapped.

Captain078 · 02-15-2002, 10:07 AM

Exactly... I've had that bracket break three times now. If it's a DC Sports, they'll raplace the whole header for you underwarranty (don't know about other companies) but trust me, it'll just break again. Mine broke exactly a week and a half after I replaced it. The unofficial word on this... bend one half of the broken bracket back so it doesn't rattle against the other half... don't worry, the bolts on the head and the cat are enough to hold the pipe... the only reason that bracket is there is because the stock header has it too.

chomorro · 02-15-2002, 02:18 PM

I just cut my bracket off when it broke. No side effects, and I have had it for awhile.

sgvprelude · 02-15-2002, 03:23 PM

mines is between 1-2k rpm and seems to be comming from under the valve cover somewhere...i did a search and some ppl suggested a valve adjustment. but i'm not sure that's the problem...any ideas? anyone?

SlvLude · 02-15-2002, 04:04 PM

I know it's hard to describe noises in words but I just had 2 seperate noises I had to take care of and some sounds like it maybe one and some the other.

The first which was several months of dealing with bad mechanics turned out to be faulty auto tensioner for the timing belt and then when put back together not properly tensioned, It made a noise I would describe more of a clanking noise. With the hood open and pressing on the throttle cable or have someone press the gas to make the noise it could be hear mostly from the front of the engine (not how it is mounted but where the #1 cylinder is)

The second which I just fixed last week was more of a buzzing or rattling noise which was being cause by my AEM CAI. It was typically very RPM specific more like 3-4k and mostly did it when coming down in acceleration, when I just put the clutch in to shift it would make it the noise beause the rpms would begin to fall but would go away if I pressed on the throttle. This was caused by the mounting bracket on the CAI. the bolt had come a little loose and AEM bracket was rattling against the factory bracket that is real close to where it mounts. It was kinda weird that it was RPM specific but ohh well I am now rattle clank buzz free. (From inside the car when driving it sounded to come from the front passenger side of the car)

Good Luck all
-Jeff-

sgvprelude · 02-15-2002, 06:07 PM

at an engine idle...mines doesn't make any noise..like slvlude's i would have to press the throttle cable or have someone press the gas...but it would have to be very specific rpm ranges. At first i had that heat shield thingy problem with the DC headers. but that problem has been solved. that clanking noise buggs me so much i feel like kicking my car for all these stupid problems.

SlvLude · 02-16-2002, 07:26 AM

Have you been able to isolate or at least have a pretty good idea of where the noise is coming from?

-Jeff-

Joon525 · 02-16-2002, 07:54 AM

Quote:

Originally posted by sgvprelude
mines is between 1-2k rpm and seems to be comming from under the valve cover somewhere...i did a search and some ppl suggested a valve adjustment. but i'm not sure that's the problem...any ideas? anyone?

It MAY BE the autotensioner.

MrPreludeSH · 02-16-2002, 10:41 AM

OK, I may or may not have the exact location of your problems but here goes.

I have an SH, anyone with the SH who gets the buzz between 2700-3500 RPM, it is the heat shield for the ATTS unit. It is located above the exhaust pipe right before the Cat. it has 3 bolts on it, two on one side and one on the other. Honda TSB says you need to install a washer or 2 to move the heat shield further away from the ATTS. I hope this helps.

Anyone with the base model, I have no clue.

Keith