Scottobot

I'm hearing a sound like broken glass/beer bottles rattling together when I accelerate from a stop (like something's shifting from the trunk or towards the rear of the car). When the car was safetied the mechanic noted a rattle sound coming from the exhaust which I had not heard when I test drove it. Could it conceivably be something in the exhaust? Or any other thoughts?

9krpmrx8

iTrader: (46)

It could be destroyed cat converter particles in the piping an mufflers. It happens. Also search for "marbles in a can" it is another common issue that may be what you are hearing.

Scottobot

Thanks for the feedback.. it sounds more like something shifting than anything related to engine RPM etc. I'll see if I can hear it sliding the other way when stopping.. haven't heard it so far but I'll pay closer attention.

Reoze

Any chance it could be coming from the wheels?

Scottobot

Slim to none. Sounds closer to the cabin and not related to speed of the rotation of the wheels (beyond "starting from a stop").

Scottobot

Next noobish question: am I doing damage to my car by driving it if the cat is in fact damaged? It's performing beautifully.. except the coolant light comes on occasionally.

Reoze

When the cat clogs up, you can fry your engine pretty quickly.

Legot

iTrader: (1)

Not likely, assuming you have a nicely sized hole in the catalyst.

Scottobot

This is what I was thinking too, but if I had a hole in the cat it shouldn't have passed emissions...

Oh well I should get it checked out ASAP.

Steve Dallas

I have seen cats blow out, and I have seen cats completely clog. This is not something with which I would trifle.

wannawankel

You could hope for this (marbles ejected from the can)

Scottobot

Well I have a CEL now so I'll be getting it checked out ASAP.

Scottobot

That doesn't look good..

CelestialGryphon

iTrader: (1)

If RX8 makes weird nose = Stop driving immediately. That should be the way ya do things.

Scottobot

Sound advice, thank you. I just hope I haven't done too much damage in the meantime!

CelestialGryphon

iTrader: (1)

Advise to stop driving and get a compression test after repairs are made to ensure you didn't blow the engine.

Scottobot

Thanks, I had a compression test done less than two tanks of gas ago.. think I could have blown it that quickly? It shows no typical signs of low compression (i.e. no trouble with hot starts).

CelestialGryphon

iTrader: (1)

You gotta remember these cars are incredibly fickle. The slightest thing wrong such as a backed up cat or a clogged cat WILL flow backpressure into the engine and just make for lots and lots of suck. Whenever I have anything that sounds weird with my car that isn't a heat shield or anything like that when I investigate I ground the car and use my DD if it's in the summer. It's already a challenge to keep maintained, no reason for me to make it worse on myself to blow an engine.

Reoze

Get a $10-20 CAN/ODB scanner on amazon and pull the codes. It could be something completely irrelevant. If your car throws codes half as often as mine does, you won't regret it.

graexodus

sounds like a catalytic converter to me...

Scottobot

My guess too. Strong smell of gas.

graexodus

Avoid driving it if you can, a damaged cat can quickly destroy an otherwise healthy motor.

graexodus

Unfortunately with our cars a gas smell is not always indicative of a failed cat, we will always have fuel smell from the tail pipe. Have you checked your CEL?

Scottobot

Not yet, just ordered an OBDII reader, should be here by Friday!

Scottobot

Yep, parked until I can take it to the stealership next Wednesday.