Heat Sheild Rattle??

[E85]

Starting a week ago, noticed that when my car's engine revs are just above idle and at 1800 rpms, there is a rattle that comes from the back of the car. probably the heat shield at the muffler, but not 100% sure.

at 1600 rpms, no noise
at 2000 rpms, no noise

so if you rip thru 1st to say 3500rpm-ish, there is a quick rattle when it goes thru 1800 ... when you go to 2nd, i'm above 2000 rpm so there is no rattle ... that's my "fix" for now to not hear it, keep revs above 2000

but has anyone else had this problem before? not about the 1800 rpm thing, but a loose heat sheild??

thanks

 

[Incompatible]

Starting a week ago, noticed that when my car's engine revs are just above idle and at 1800 rpms, there is a rattle that comes from the back of the car. probably the heat shield at the muffler, but not 100% sure..... that's my "fix" for now to not hear it, keep revs above 2000 but has anyone else had this problem before? not about the 1800 rpm thing, but a loose heat sheild?? thanks

It's qucik and easy enough to take a look under the backend of the car. If you don't find anything, then it's up on jacks to start looking for something that's loose and rattles.

 

[cj10jeeper]

I suggest that since you know the rough area and the rev range, get someone to riase and lower the engine revs while you have a look and safefy press the heat shield where you think it could be.

In my experience noises rarely come from where you think they are, but at the same time the likes of heat shields you mention do tend to fatigue off at the mounting points, but usually in the engine bay, not the rear.

 

[E85]

Thanks. That's what I figured I had to do, but just wondering if it was a common problem or not. The noise is definitely coming from behind me, not in front of me (ie. not the engine). But yes, I agree, it could easily be a heat shield in the engine.

Just kinda weird how it only rattles at that particular rev range. It's like that muffler omits some specific frequency at 1800 that makes the heat shield rattle. Like an opera singer using her voice to break glass at a certain frequency

CJ, if it does "fatigue off the mounting points", is it just a couple turns of the wrench to tighten it? Or does it involve welding?? Or something else??

 

[cj10jeeper]

If it is a heat shield then it will likely have sheared off around a bolt, but that's all supposition. Repair or new bit depends on who you know, where the problem is, what it is, etc.

Find it first, post a picture and someone will advise.

 

[Adam]

I'm have the exact same problem at around 1800 - 2000 rpm....only had the car for a month and I'm sure it wasn't doing this when I bought it! I got mine from a main dealer so it still has 12 months warranty, but I would rather sort it myself so I'm not without the car.

Let me know how you get on finding the culpret!

 

[Adam]

Starting a week ago, noticed that when my car's engine revs are just above idle and at 1800 rpms, there is a rattle that comes from the back of the car. probably the heat shield at the muffler, but not 100% sure.

at 1600 rpms, no noise
at 2000 rpms, no noise

so if you rip thru 1st to say 3500rpm-ish, there is a quick rattle when it goes thru 1800 ... when you go to 2nd, i'm above 2000 rpm so there is no rattle ... that's my "fix" for now to not hear it, keep revs above 2000

but has anyone else had this problem before? not about the 1800 rpm thing, but a loose heat sheild??

thanks

Have you found the cause of this?

 

[E85]

Sorry for late response Adam and others ...

The exact cause, not 100% sure. But it's fixed. There were actually 2 noises. A "rattle" and a "squeak". Found the squeak, it came from where the muffler hangs on to a rubber thing (i know, i'm sooooo technically correct ) that is screwed onto the car. The aluminum/metal hanger that is welded on the muffler is in direct contact with that rubber thing and it must have gotten dry, so when it moves a bit it squeaked.

More specifically it was the hanger attached to the muffler that is the most "rear" and most "left" on the car ("left" = driver side for US cars)

Here's how I "fixed" it. When under the car, tried to pull the rubber thing off of the hanger to lube it. While trying to work the rubber thing off to lube it *insert your own joke here*, THE HANGER SNAPPED OFF THE MUFFLER!!!

What's really weird and should have no consequence here is that my "service engine light" went on twice while the car was making those noises, but then went off by itself before the muffler was fixed and afterwards and hasn't been back since *knock on wood* ... probably some kind of weird coinsidence?? How can a rattle and squeak in the muffler HANGER = service engine light??

Brought it to a local exhaust shop and had it welded back on (with the hanger lubed) and now all unnecessary noises are gone and the way it was welded, that part of the muffler is stronger than ever.

 

[Bobbydm]

Sorry to bring this one back up but Adam, did you manage to stop your rattle by checking the exhaust bushes? I have the same ratlle 1800 rpm to 2000 rpm exactly and assumed it was from the engine due to the nature of it. i.e a valve that opens/closes around that rev range. So far I've tightened up the sound generator thinking it was that...sadly it wasn't!

 

[Master00Sniper]

I'm bringing alive an old post here.

My 2003 3.0i has the same kind of rattle I think. It's relatively high pitched, like a fast metallic rattle. I get it exactly at 1800 and 2000 rpms as well. (it also rattles a vary light amount at other low rpms, but mainly at those 2). I thought it sounded like it was coming from the front of the car, under the engine, but one thing I've learned (and someone else mentioned it up above) whenever I've heard a sound coming from the engine, it's never where I thought the sound was coming from.

I'm bringing it into a mechanic on Tuesday, just in case he may not be able to find it, i'd like to at least have ideas I can present to him from other people with the same problem.

From what I've read, it sounds like the different possible engine rattles are

-DISA valve
-Heat shield
-Muffler hanger

One thing to note, my check engine light is on as well, and I'm not sure if the rattle was present before hand, but after it came on I started paying attention a little bit more and I noticed it. (I usually drive with music blasting, so I can't be sure if I just didn't hear it, or if it wasn't present).

My Miata had a rattle that sounded similar, except at 3000 rpms. Turned out it was the heat shield.