MainelyA8

Parked my car, locked it while it was running, and heard this lovely noise coming from the engine. Popped the hood, and it seemed to be coming from under the timing belt covers. Has anyone heard anything like this, or have any idea what it could be? It didn't appear over the next hour and multiple starts/stops, and I don't have any new VAG codes that came up.

Jack88

Did you take the covers off and see if there was anything irregular under it? Sounds like some belt rub to me, but I'm not sure.

MainelyA8

I did a few days ago, and everything seemed in order. I did notice that the belt was fairly loose at the top, but I also read that it's normal to not be as tight up top as it is towards the bottom.

Jack88

It is normal for there to be a bit of slack, but too much is a problem. I'll have to defer to the experts, though, as to exactly how much indicates a problem, I've only had the covers off a couple times on a D3. Check under the covers again, couldn't hurt to see if it's any different since the noise. If you had a failing tensioner, you wouldn't get any trouble codes before failure. How long since it's last timing belt maintenance when all the things were replaced? Do you know what parts were used?

MainelyA8

I'm not really sure how to gauge what is too loose either; maybe I'll make another home movie once it stops raining.

I just had the second timing belt service done about two weeks ago, and everything on the timing belt and serpentine belt tracks where replaced. I believe that everything used was Continental, but the thermostat and water pump were OEM.

Jack88

I'm always suspicious of fresh work. Might be worth mentioning it to the shop. They can reset the tension on it in a couple minutes, IIRC. How sure are you that noise was behind the covers? Acoustics can be a real strange and misleading mistress. It's sounds rhythmic, so anything attached to a pulley is a suspect.

Junius

How long has it been since you had the timing belt job done? Take it back immediately before anything gets worse

mishar

Sounds like timing belt tythm, may be serpentine belt too. If it comes from the timing belt it can be serious, especially coming after the recant replacement. If it was not done properly belt may be damaged and rubbing against the cover. Check it as soon as possible.

MainelyA8

Thanks guys. I'll check it ASAP tomorrow. Maybe run the engine with the covers removed to see if anything looks off. Shop stated that since I supplied my parts (instead of using their $1000 timing kit, without a T-stat), there's no warranty on the job. Hopefully if there is anything going on, I can get them to check it over anyways.

Luckily, haven't heard the noise since and everything seems to be running smoothly.

MainelyA8

It's been about two weeks. That was the first noise, or anything suspicious that I've heard since I got the car back.