Deisel noise and black greasy grime in exhaust

[sip]

My 6 month old 2009 Mazda 3 has two problems:

1) After driving for 10 or 15 minutes, it sounds like a diesel engine (but not so loud) when idling. I hear that most forum members have the same problem and dealers claim that it is normal. I fear that I would have a problem when it comes to sell this car, as the buyers would think that there is a problem with the engine.

2) There is a thick coating of black greasy grime inside the exhaust tip. I have seen older 2009 Mazda 3s with relatively clean exhaust tip. In fact, I haven't seen a dirtier exhaust than mine. I am concerned, as this could be a symptom of some problem

Any comments or advice will be appreciated.

[Zoom Zoom Boy]

My 6 month old 2009 Mazda 3 has two problems:

1) After driving for 10 or 15 minutes, it sounds like a diesel engine (but not so loud) when idling. I hear that most forum members have the same problem and dealers claim that it is normal. I fear that I would have a problem when it comes to sell this car, as the buyers would think that there is a problem with the engine.

2) There is a thick coating of black greasy grime inside the exhaust tip. I have seen older 2009 Mazda 3s with relatively clean exhaust tip. In fact, I haven't seen a dirtier exhaust than mine. I am concerned, as this could be a symptom of some problem

Any comments or advice will be appreciated.


Impossible to diagnose whether your engine noise is normal for these cars without a sound clip. However, these engines do tick to some degree, but there is a great variance amongst each car.

Black soot is usually the result of an engine and car running overly rich on the air and fuel mixture. The turbo Speed3's for instance, tend to run very rich and our exhaust tips are perpetually black unless cleaned regularly. The regular MZ3's shoudn't be running overly rich. A little bit of black soot is normal, a lot is not. What type of gas and gas grade are you running?

[TheMAN]

the easiest thing to do is to just go to the dealer and let them figure it out... the car IS under warranty after all

[Zoom Zoom Boy]

the easiest thing to do is to just go to the dealer and let them figure it out... the car IS under warranty after all

Ya, agreed...

[sip]

I use regular Petro Canada gas. I am taking the car to the dealer but suspect that dealer might say both the diesel noise and black greasy grime in exhaust are normal. I was looking for some advice to challenge it.

[Flagrum_3]

I use regular Petro Canada gas. I am taking the car to the dealer but suspect that dealer might say both the diesel noise and black greasy grime in exhaust are normal. I was looking for some advice to challenge it.

Do you do alot of short trips? This could explain your black, greasy tail pipe.

As for the noise, the MZ3 is pretty noisy to start with but I found (with my vehicle), switching to a 30 weight oil as in 0w-30 or 5w-30 seemed to hush the engine down a bit.


_3