Hi...new to the forum. I've been poking around, great stuff here..but I have a question.

I purchased a 2007 Mazda 3 S Touring 2.3 (manual transmission) 2 weeks ago. I didn't notice it when I test drove it, but when I got it home, I noticed a faint knocking sound coming from the engine. You can hear it from the inside of the car, and when you lift the hood, it sounds more like something shaking than knocking. I'm not sure what is. I took it back to the dealer, and they couldn't figure it out either. They brought over 2 other Mazda 3's (same model, same transmission), and they all seemed to be doing it too. At this point, they don't have an answer, other than to say that it might be a manufacturing defect. I'm not too concerned, because it runs GREAT, but it's still very annoying.

I can hear the knocking when it's sitting idle, and most times, the knocking seems to get a tiny bit louder when I slide it into gear but leave the clutch down. When it's running, I can hear it at low speeds, and from time to time, at high speeds too.

Anyone else experienced something similar? Just curious. I'm not very car/engine savy, and the fact that I heard the same noise in two other same model cars puts me a little at ease, but a knocking noise from the engine is still a bit alarming.

 

I have never heard it knock. I you sure that it is knocking and not just the transmission?

 

Definitely not the transmission. Just a very annyoing knocking/muffled ticking noise coming from the engine. You can hear the sound a bit louder when sitting in the passenger seat.