So I finally passed the 1200 mile mark on my ride home from work this evening and decided to be a little more generous with the fun pedal than I have been during the break in period . So from a stop I punch it fairly hard up to about 5.5k RPM and noted a "strange" noise coming from the engine bay, kind of like a puttering sound that increased in frequency with the RPM's .

This gave me a bit of concern and I wanted to check with you guys to see if this is normal or if not get some potential leads as to what the problem may be. I am heading to the dealer on Friday morning anyway to pickup my touch up paint and figure I'll discuss with the service manager, but I'd like to avoid being totally off base/paranoid on this.

Here is what I have noticed and what I have checked so far:

Symptoms:

• Puttering noise when accelerating from 0 - 50 or so with driver side front window open about 1/2 way.
• Puttering noise present but at decreased volume with all windows closed. (Duh )
• When accelerating slowly I do not notice the noise irregardless of window position.
• Engine does have slight "ticking" sound when idling in my garage, but based on some other threads (yes, I searched before posting ) I have read this seems normal for these engines and is most likely the injectors. I have tried to record this but my camera's video capability is lacking and the tick gets lost in the other ambient noise but if you're standing in front of it you can hear it.
• I do not hear the noise when car is in P and rev'd.
• Oil and other fluid levels are fine.

Any input/insight would be greatly appreciated.

 

Does it do this when the car is cold? If the sound goes away after the car warms and just does it when its cold its probably the emissions control on the car doing its work. It makes like metallic sound, kind of like a puttering i guess. My VW toureg does it as well. Then it goes away. You can check with the dealer to make sure but im sure thats what your hearing... Its normal.

 

What grade of fuel are you using?

 

kca2000:
It does this when the engine is warmed up, I have not tried it yet while cold, but will give it a whirl at lunch time and report back.

Tiger:
I am using 93 octane. I typically gas up at the same station all the time, but maybe I'll try another station to see if I got a questionable tank.

Thanks for the replies so far, keep them coming.

 

Also, while you are out at lunch, test to see if it gets louder when you are climbing a hill. If possible, have your A/C compressor on. Put a load on the engine to test for detonation.
I forgot to ask, does it sound like detonation to you?

 

It doesn't really sound like detonation to me, meaning it's not a "ping" noise that I hear, but more of a "fluttering". Damn, car noises are hard to describe aren't they??

 

could be a faulty cat. converter on the exhaust. Most "fluttering" noises come from a bad cat.

 

Good point on the cat. I'm kind of hoping that's not the case, but if it is that's what the warranty is for.

One question, could this also be from an exhaust leak or something as well?

 

I was thinking an exhaust leak at a gasket, or possibly a pin hole at a welded spot around a flange.

 

The more I think about it I agree that this may be an exhaust leak, which would explain why it's there only under "spirited" driving and wasn't noticed during the break in period when I was trying to be smoother on the throttle.

So does anyone know of a quick way to troubleshoot this myself (I have a fairly extensive understanding of leak checking vacuum systems) or is it best to take the car to the dealership?

 

Is it a tapping noise from the dash area? There was a service bulletin in February for removal of silicone debris from the heater core. It says the tapping noise will start when at operating temperature and the tapping speed will increase and decrease with engine RPM. The sound is described as a screwdriver tapping on a work bench.

 

did you change your oil after you hit the 1200 miles? If you didn't, I gotta ask you why you bothered babying it at all?

 

The 1200 mile break in is meant to break in more than just the engine, it also helps pretty much every mechanical system in the car. Thanks to the manufacturing technology used today there is very little debris from the engine and the oil filter is adequate for catching it. There is really no need to change your oil at 1200 miles.

 

Christian,
I have seen the service bulletin, but to me it doesn't sound like a mechanical tapping noise (but I am by no means an expert) but more of a fluttering like I have said. I am going to give a call to the dealer soon and see what they have to say, keep the ideas coming guys.

 

Well I took the car into the dealer this AM for one of the techs to look at and after some 0-60 runs on a secluded back road I was able to repeat the noise with the tech in the car, his take on it was that the noise was due to the variable timing, being the cynic I am I tried an 07 loaner they had handy and lo an behold it had the same noise under the same acceleration conditions, so at least I am confident that it is "normal". Wheww .

While I was there I had them order the seat warmer harness and pointed out the few pits I have on my grille, the service manager seemed to agree that the pitting was "not right" for a car with only 1250 miles and would see what he could do.