Stumble

[Dan DiBiase]

On 11/3/11, Dan DiBiase <d_dibiase at yahoo.com> wrote:
> I've noticed a slight stumble during acceleration in my car over the past
> week or so. Basically, in most gears, when the car is
> warmed up, there is a slight hesitation or stumble while accelerating - it
> always occurs around 2,000 - 2,300 rpm, regardless of
> which gear I am in. It feels like an interruption in the engine power, or a
> hesitation. No CELs have come on, and the TB was replaced
> at 75k miles (currently have 109k). Any thoughts on what could cause this
> stumble?


Ok, I finally got around to doing some additional diagnostic work. None of the local auto places will pull codes
without a CEL, and when I loosened my gas cap to try and generate one, it never came on! Since several suggested
the MAF sensor (and Google suggested same) I disconnected the wires and drove a bit and it seemed to drive a lot
better. So I ordered one from Chris at Force5 and replaced it last Friday. Car DOES run better but still a little
'stumbly' although not as definitively (i.e., not always at the same rpm level as before). 

So Sunday I was leaving to drive an hour and a half for a Christmas lunch with my family and the CEL came on a
mile from my house. Went back and we took the Odyssey instead. Today I went to Autozone and they pulled up a
P0118 - Engine Coolant Temperature circuit fault. Googling indicates that it is the G62 coolant sensor at the
back of the had. So guess I will pick one up and replace it. I also read somewhere that it could cause a stumbling
condition, so perhaps that is the true culprit here.

Dan D
'04 A4 1.8Tq MT-6
Central NJ USA