Paging irish44j and other WRX gurus...tapping noise upon acceleration?!

Man, the paranoia with this car is getting kinda overwhelming. If I didn't work 80 hours a week, I'd probably have been admitted to a Psych unit over all the rattles and noises this car makes a long time ago.

Here is the deal. 2013 WRX Limited hatch. 9600 miles on it. Returned a few days ago from a body shop after having rear bumper replaced (someone tapped me in the snow a few weeks ago). No other repairs performed or needed, just the bumper cover. Since then, car has been making a slight tapping noise (like 1-2-3 taps and then silence) upon accelerating in 1st gear. Can't hear these taps over music or climate control. Occasionally hear a similar tap or two upon going into 2nd and 3rd as well. I know what the release bearing whirring sounds like...its not that. I know what the ABS self check sounds like...not that either. This is a new sound which has just started. I've driven the car to Minneapolis in subzero temps and here in Akron in freezing temps, and the sound seems to have no relation to that. Originally I thought maybe its one of those soft Subaru trans bushings just playing around in the cold, but now I am getting paranoid. Car has been running 100% fine both under driving normally and in a spirited manner.

Thoughts? Ideas? Go to the dealer? Xanax? I need answers. PLEASE.

Something loose in the bumper that was fixed. It's the only new variable.

Thinking exhaust hitting the bumper.

It's under warranty, take it to the dealer.

Bryce

I could totally see part of your exhaust moving/swaying/bouncing when you hit some uneven (not nescessarily rough road) and the rubber bushing allows 1-2-3 contacts with the bumper or whatever before it settles down. Get a friend to team up and shove the back of the car down with you while you listen for the resulting bangs/taps.

Yeah, maybe a heat shield tapping or something.

Only thing else I can think of is if your exhaust itself was hit and when it was pushed forward, it caused a small crack someplace, so you get a bit of a leak until the temperature rises and seals the crack. That's a longshot though.

In any case, not a sound I'm familiar with on this car. Though with mine at 90k miles and beaten hard, I've given up worrying about noises, lol...

Appreciate the input guys. Sound does come from the back of the car and only upon setting off. The sound happens more often when taking off uphill, if that helps. Exhaust hanger sounds viable but when I parked and shook the car, everything stayed put...anything I can do to replicate drivetrain movement while parked and figure this out once and for all??

I once was doing an autocross and kept on hearing a clunking sound on acceleration. Like a hard "bang" from the back seat floorboard. After much head-scratching and looking under the car, I discovered the small socket rolling around the metal area under the back seat. No idea how it got there.

Check and make sure you don't have something in the trunk that slides back when accelerating and going uphill and rattles against something else, perhaps?

I am super-ultra OCD. I leave absolutely no loose items in the car. The hatch area is completely empty. I think the exhaust hanger idea sounds reasonable, but I am wondering why the sound would only happen on low load takeoffs and not when I'm gunning it around the rest of the day. Perhaps I just don't understand the mechanics of exhaust movement that well.

on low load there is more engine vibration....so things vibrate that don't at higher loads....especially on a subaru.

Jack up the car with a floor jack then crack the release valve/screw quickly. That'll replicate a sudden rise/bump in the road.

ebonyandivory wrote: Jack up the car with a floor jack then crack the release valve/screw quickly. That'll replicate a sudden rise/bump in the road.

Thanks for the input, hope that this turns out to be something as simple as an exhaust hanger!

Did the hatch get hit and are its rubber bumpers still in place?

Hatch was untouched. Literally got tapped, just a small crack in the bumper.