Engine rattle

The engine of my 2008 CX-9 started making a rattling noise after about 5000 miles. Initially a faint rattle, it occurred at about 1500-2000 rpm while accelerating in every gear except 1st, and only when the engine was warm. By 6500 miles, it was making lots of noise as soon as the engine warmed up, regardless of what gear I was in or whether I was accelerating, coasting, or decelerating.

My Mazda dealer says they have no idea what it is, but they can definitely hear it, and they've been working on it for over a week. It also took the dealer two weeks in total (over three separate visits) to finally correct a pull-to-the-left alignment problem when the car was brand new, so I'm not sure if the rattle isn't something that simply wasn't tightened during those early visits.

Anybody with engine noise like this?

Engine Rattle

My CX-9 has rattled when shifting in and out of 4th, 5th and 6th gears since I have owned it. 1, 2, 3...no rattle. Dealer hears it, but can't find anything wrong. They initailly thought it was engine knocking (the sound is similar), but the rattle is still there even with a tank of premium unleaded. To me, the rattle is more realted to transmission than engine. Anyone else getting this?

Update 6/2/08 The dealer called and said the sound maybe caused due to the K&N air filter?!? I told them I have had the K&N in the vehicle since the second day I owned it and now at 15,000 miles it is starting to make noise????? Well If anything I will buy a regular filter and run it and see what happens.................I don't think that could be the issue.


I am getting a knocking/pinging sound under acceleration when the engine is cold. It happens for the first few minutes. It also happens for a split second when hitting the gas. I am taking mine in for service Monday and will mention it to my service department. (Gregg I have to agree with you about the tranny because I put mine in neutral and hit the gas and no noise. It only happens when I am moving).

Detonation happens when the engine is cold, I have noticed that.

I tried mid-grade gas but while the knocking(detonation) was eliminated I don;t hink it's worth the extra cost.

YMMV.

Well I took the CX-9 to the dealer yesterday and they checked a few things and it didn't resolve the issue (they are not blaming the K&N anymore). They called Mazda Tech Support and they are going to send a new intake manifold to try. My service manager said the part number that Mazda gave him isn't even listed on their computer, so maybe it is a redesigned manifold. Atleast they are trying and not just telling me the noise is "normal" since it only started at 14,000 miles. Once I have the new part installed I will update my post again...........

Could it be that the 2008 model has a redesigned intake manifold than 2007?
I am assuming that you have a 2007 since you join this site in July 2007.
Mazda tuned the Ford engine (3.5L used in 2007 model shared with Edge) and upgraded it to 3.7L with some improvements including the intake manifold, I think.

ceric said:

Could it be that the 2008 model has a redesigned intake manifold than 2007?
I am assuming that you have a 2007 since you join this site in July 2007.
Mazda tuned the Ford engine (3.5L used in 2007 model shared with Edge) and upgraded it to 3.7L with some improvements including the intake manifold, I think.

Click to expand...

I have a 2008 with the 3.7 V6