Carbon buildup and engine noise, true/false?

[cody_au]

I was filling out the questionnaire form from a dealership about my Lancer purchase, and I've been very complimentary because it was a very good experience, but also wanted to list what stood out to me as not-so-great.

One of those was, when I took it for a test drive, the salesman said something like, "It will be less noisy over time because the engine is oriented differently (transverse) and carbon has to build up on the exhaust back-plate." This was on a demo car with tonnes of km's on it already (I forget exactly how much, 5,000-10,000).

I mentally sorted that into the bullshit file, sure the engine is rotated a bit compared to how they used to be, but carbon build up isn't going to change the noise coming from there. But before I note it down, is he right and I'm just misinformed?

[JustinR]

I think theres truth to that yes, when i had the exhaust replaced on my Lancer, the note was a tad higher, now after driving it around for a couple thousand K's, carbon has built up, and the note is a tad lower. Dunno about the engine though, i bought my car used. The only changes i've noticed have been due to the modifications ive done.

[cammag5]

I think what he ment to say was "It will be less noisy over time because you will get used to it"

[Chubb]

Carbon is an insulating material so it will act as a deadener as it builds up over the km's