jsmith24

Hello again!

I've got a weird rattle/knock/tap sound. It's not there at idle, or if it is, it's not loud enough to hear. But, when cruising with an RPM of about 2000, there's an intermittent, "pulsing" rattle/knock/tap sound. What I mean is - it's a quick/short sound with about a one second cycle, that starts quiet, grows louder, gets quieter, then silent, then a half second later it does it again. It doesn't do it all the time, only in a certain RPM range.

I have a 6 speed, and it will do it when sitting in neutral in the drive, though it's not as loud (probably because it's not under true load).

It seems easier to hear inside the car rather than under the hood. It seems to come from the passenger side, though it's hard to say that the dash doesn't muffle the sound on the driver's side.

I just did an oil change thinking I might have gummy lifters/valves, but if it were lifters, valves, or some other internal component I would think that it would be a constant sound, not this intermittent, pulsing or cycling sound.

Any ideas? I thought it might be the timing chain, but the car runs great, just makes this noise.

The engine has 244,500 miles, give or take a mile, and has been relatively well maintained. I just had the clutch replaced, alternator replaced (couldn't do those myself this time - back surgery), replaced the front valve cover gasket...I think that's all.

Any help would be much appreciated.

Jack

PS: Yep, I did a search, but didn't find anything that sounded like what I have.

Bronxboi5

Well I just solved mine and just like everyone else it might be your heat shield under your car

jsmith24

Well, go ahead and flame me for my ignorance, but um, "heat shield"? Surely you don't mean that bit of plastic near the front, do you?

My sound is definitely metallic. Again, if I'm just ignorant, let me know and tell me where this thing is!

Thanks,

Jack

Marc2theMax

What he means is the heat shield thats located on the y pipe part of the exhaust. Same thing happened on my car. But like you i also had the rattle sound coming from the passenger side engine compartment too. Seemed to happen on light throttle. Very noticeable sound inside the car. I suspected it to be the Vias after listening very closely to the engine. So i bought the nwp block off plate. To my suspicion i was right. After taking out the old vias and replacing with the nwp bop the rattle sound disappeared. Do a search on nwp engineering bop and youll find out how to do it.

Now that could be your problem or it can not be. Hopefully not anything to do with your timing chain or components or Precats. Since your car does have alot of miles.

Or like what happens to most people is the heatshield rattle. What you have to do is jack up the car and get under there. Locate the y pipe part of the exhaust towards the front of the car coming off the engine. What i did was get a rubber mallet and just bang around lightly. Thats how i found the rattle.

Well hope that helps you some. That was my experience. Goodluck!

jsmith24

Thanks for the info! Believe me, at this point I'm willing to smack things with a mallet.

I'll look into the Vias, though right now I don't have a clue what that even means.

Thanks,
Jack

jsmith24

Hey again -

I just read a post about the heat shield, and it mentioned the frame member down there. I also seem to remember that the transmission shop that did the clutch said they had to remove that member...so - wouldn't that mean there's a chance that something got moved a tad, and it actually *could* be heat shield rattle? I mean, I never had it before...

Jack

Marc2theMax

Ya it sounds like that could be a possibility. You wont know for sure until you get under the car and take a look. What i found was a little bracket piece broke off of the y pipe area around the heatshield. Im not sure where it came from but that definitely what was making the rattling noise. Like i said though it could be a number of things making the noise. Its been discussed a lot of times on this forum already. Goodluck man hope u figure it out.

Bronxboi5

I hope you got your answer.... Trust me it was annoying until my father closed my door to move my car and I heard it.... Inside the car I really couldn't hear it

jsmith24

Thanks, man...I need a little luck. After all the cash I just dropped on her, the last thing I want is something big to go wrong, you know?

Jack

jsmith24

Yeah...on an unrelated note, when I close my door I hear that annoying "squeaky" from the front clip/fender area. I figure it's just one of those chintzy little metal braces in the wheel well somewhere, just never tracked it down. I know it's in that area though, because if I kick the tire hard enough I can make it squeak again.