Bapo

There seems to be a loud rattling sound that seems to come from under the car. Someone had a similar noise coming from a BMW and they told me it was a loose exhaust, but when I get under the car (no small task), everything looks real tight.

Any ideas? Just hoping to get an idea of what the repair bill will be, or if I might be able to remedy the problem myself.

Squishy

Cats are bad.

Covered under emissions warranty 8 years or 80,000 miles.

Take it back to the dealer.

Buellwinkle

It's probably a lose heat shield. Get under it and shake any heat shield and see if they wobble. I doubt it's the cat, if it got to the point where it's insides would rattle, it would likely be clogged and you would notice a drop in performance and/or rotten egg smell in the exhaust. It could be a lose exhaust but if it's that lose it may be corroded.

99 slk 230

I had a rattling noise, but only for a few seconds in the morning, when I would crank up. It took me awhile, but I finally figured out it was a heat sheild, right over the muffler. I had it pushed back about 2mm, that's all. Problem solved.

Bapo

Thanks for the suggestions. I'm gonna see if I can get under it. I sit really low so it’s hard as hell to get under. I'm thinking its a heat shield, with all the bumps and as low as I sit I probably knocked one loose.

Buellwinkle

One trick I've used over the years, comes in handy when evaluating a used car purchase is to drive one side of the car, 2 wheels on curb, taller the better and make sure parking brake is on real good. Gives you a few more inches to crawl under.

Bapo

Well I just found out. It is my catalytic converter My mechanic wanted to charge me $1,000.00+. Luckily I'm covered under warranty. Going to take it to American Service Center and pray they don't find some way out of the Warranty. I'll let you all know.

pojr

my converter went bad on a cross country trip. Started with a sound like a rock was in the heat shield and got worse. Stopped by the Albuquerque Mercedes dealer and they had the part send overnight so I could be on my way. The Las Vegas dealer would not even look at the car for a week, even though they knew I was on the road. All costs were covered, without a problem.

Bapo

Yeah. I got my car fixed at American Service Center in Arlington Va. People were nice and I got it fixed in a few hours. I was exepecting to be without my ride for a few days. Quick, easy, and free. Can't complain.

Squishy

Bad cat you say?

Bapo

You called it. Props to you.