After three weeks driving Mazda 3 (I told the service rep that we just got back from a road trip up and down the Alaska highway), we got our '04 AT back with a remanufactured engine and new tranny. Both my wife and I noticed that the engine seemed louder (rumbling) at idle (but only when in drive--in neutral it quiets down immediately). Does this seem normal?

Also, do we go through the break-in procedure all over again? We've been driving it with that assumption, but I don't know if this is necessary with a remanufactured engine as opposed to a truly new one.

The car went in with about 24,000 miles, was getting about 16 mpg in city driving, low twenties on the highway.

Also, if we ever sell the car should we tout the new engine or low key it?

Thnks for any thoughts.

Not sure about the rumbling, but you do need to break the engine in.

LTABA,
You had good gas mileage - what happened to the old engine and tranny?

I got a reman also, but the service manager and the tech who worked on my car both told me not to worry about the break in period. But I did it anyway, taking it easy on it for about 600 miles or so.

If by rumbling you mean vibrating, it might be bad motor mounts (something they should of upgraded when they swapped out your engine.). For me it only registered when in D and never in P or N.

why did they replace your engine and tranny?

Well I'm not sure I have the perfect answer, but the car just started stalling at every stop and we managed to limp it into the dealer. They checked it out and came back saying new engine--I assume compression was shot. As for new tranny, I didn't expect that, but it was on the work order when I picked up the car a couple days ago. Is that not normally a part of the engine replacement?

Nope, engine and tranny do the "work" together but get replaced separately, and each for its own reason. Yours might be the first on this board to get a whole new drive train (both engine and tranny) and, AFAIK, the tranny had nothing to do with any TSB.