Hey all... I have this low metallic rattling sound at low rpm's, esp when the clutch is about to engage and it vibrates a bit... it sounds like a loose muffler, but a mechanic tells me it is the catalytic converter and it needs to be replaced totally, at about $450+. # 1, anyone else have this prob, and does that sound right? # 2, I found a cat converter for about $70 on ebay, does that sound right as well? I heard the install on these things suck, hours of work, welding, etc., so maybe $00+ does sound right on top of the $100 or so for the unit? Thanks!
I had a metallic rattling sound a few months ago. My shop also said it was the catalytic converter, but it turned out they were wrong. I found it hard to believe so I had them look again but told them where to look this time as per my brother's suggestion and he was right. It was just a piece of metal that I think connected to the headers; either that or it was an engine mount (I have no clue what any of these look like). I don't know what it was, but it was a simple piece of metal that cost a few bucks. It was a plate, kind of like a washer of some sorts, but connected to the engine in some way. I'll ask what that piece was so I can tell you exactly what it is. They need to be careful when diagnosing because spending hundreds or thousands of dollars on something that is possibly that simple is a horrible way to lose your temper and end up in jail.
LOL!!! Ya, good thing I can kinda control my temper.... thanks a lot guys, u are awesome... I'll wait for your response before going to a second opinion... the guy i went to really doesnt work on bimmers, but this other guy is recommended by a private dealer, seems like a stand up guy... only bad thing is location, so I either have to wait for it to be fixed or somehow get a friend to drive me like 15-20 miles a couple of times.... ugh.
Okay, I found out that it was my motor mount that was replaced. It was the reason it was rattling so much. The worse it got the more constant the rattling became. It started out small; only rattled above a certain rpm (certain amount of vibration) but as it got worse, it even started to rattle when idling. I simply couldn't take it anymore; it was ruining the sound of that potent M20!
Ha! well thanks heaps for the help... I will mention that to my peoples and see what they say... not sure how long i wanna wait but i need new brake pads soon anyways bec now thats making a rub dub noise.... ugh, so much money for non-performance upgrades, this sucks!
Probably a rattling heat shield. Don't replace the cat unless the tech can produce trouble codes to backup his diagnosis. Spending $2K+ (and that's what it will cost you with retail parts + labor) to fix a rattle is unwise to say the least. http://www.dvatp.com/bmw/maintenance/e36/2004/06/ -Doug
Ha ya, but u know in BMW's defense, mechanics now tell me domestic parts are not that much cheaper than foreign like they used to be, they've been climbing too... so maybe he was just trying to make me better with a cheap psychological ploy, but it worked!
You can clamp a couple of large hose clamps around the converter, and that should fix the problem. Go have a beer, and think about the fact that you just saved lots of money.
