[platinum70]

Folks

Since the drop in temperature as I go down my drive in the morning I get what seems like an exhaust rattle when the car is cold. As it warms up it seems to go, although I did hear it slightly when we returned home, but nowhere near as bad.

Any thoughts as to what it could be? Or if it's quite normal. Doesn't appear to be suspension related.

 

[Octavius]

Exhaust valve. One side stays shut off until engine warms up. Could have a dodgy spring or something.

 

[platinum70]

Exhaust valve. One side stays shut off until engine warms up. Could have a dodgy spring or something.

Would that make it rattle though? And only seemed worse since it has got colder

 

[Stevoraith]

I get a similar noise in my 125d. Haven't yet had a chance to get someone else to drive it while I clamber about in the back and try to pinpoint it.
Doesn't help that it only does it when it's cold.

Do you have active suspension? I wondered if it was related to that.

Will probably take it to the dealer while it's still under warranty but I'm not convinced they'll hear it....

 

[platinum70]

Standard suspension on mine. Wonder if it's the boot as others have had problems with the boot latch

 

[Stevoraith]

That would make sense- the boot doesn't always close properly first try so maybe the latch isn't adjusted properly.

I'm useless at pinpointing noises- a rattle in my wife's car drove me mad for months. I was convinced it was coming from the passenger door. Eventually booked it into the dealer to be investigated and when I told the wife she informed me that it was her sunglasses in the holder in the roof, next to the rear view mirror! "They sometimes do that" she said! Grrrr!

 

[platinum70]

My ex girlfriends father knew I hated rattles and tied washers to the springs!! Drove me mad for weeks. I will look at this tomorrow

 

[3xxie]

Pretty sure it's the exhaust valve as per comment above. I had this occasionally on cold mornings and it goes away before or as the valve opens after the engine has warmed up.

The valve opening is very audible, especially if you get out and stand behind the car. Many have had theirs replaced under warranty but my dealer didn't hear it so wouldn't do anything. I've since set it to always open.

 

[Stevoraith]

Does that explain mine?

Anyone know if the 125d has a valve which shuts off one tailpipe?

Of course it may not be the same fault but it certainly sounds like it's similar.

 

[Steven1077]

Tail pipe covers? Mine rattle now and then when I first start it

 

[3xxie]

Does that explain mine?

Anyone know if the 125d has a valve which shuts off one tailpipe?

Of course it may not be the same fault but it certainly sounds like it's similar.

Not sure about the 125d sorry. It may well have the same sort of valve on one of the tips, just get out and stand behind it while it's rattling.

 

[Stevoraith]

Mine doesn't rattle when the car is sitting still, it's only going over bumps at slow speed I get a faint noise.

Sounds more like the boot catch in my case I think, I'll investigate when I get some time.

 

[Riddick716]

Ive had this on my m135i drove me crazy, its the boot lock that comes loose or something inside, went to bmw they sorted it, but its back now, back to bmw

 

[platinum70]

I popped in to BMW today. They want the car for a day or so to diagnose it. Certain,y worse since colder weather but gets better as car warms up