Need advice/ input to solve my problem

[ginnai]

Hi all,

I currently have two problems, if you have any thoughts on either of them... please share your thoughts. The car is a 2006 3i 2.0L with an automatic transmission.

a) rattle on passenger side at 1500 rpm - I am getting a rattle coming from the passenger side that sounds rotational, nobody has been able to diagnose the issue. The belt tensioner pulley was replaced, but unfortunately my life isn't so simple. I borrowed a new tensioner and that didn't solve it either... so I am not sure what else would rattle only in a certain rpm range (since it sounds like its turning). All the accessory parts turn smoothly, so I don't think it is bad bearings in the alternator/ water pump/ AC or AC clutch.

b) exhaust noise - As I rev the engine up around 2-3K (in park/neutral), I get a vibration in the cabin and as I release the throttle, I can hear the typical exhaust leak sputter. My mechanic looked at the pipes and nothing jumped out, so my thought is an exhaust manifold gasket... but I have never had that problem, so I am uncertain of how that sounds/ feels.

I am try to do all my own work, but I am at my wit's end with these issues. After three visits to my mechanic, they are equally stumped. My hope is that someone has had this issue or knows the car well enough to give me some ideas. I am probably going to have my mechanic just do the work, but I don't just want to say "take it apart".

Thanks for any insights!!

[Noisy Crow]

Exhaust: suspect cracked flex pipe.

Rotational rattle: When car is in motion only, or does it happen when the car is sitting still? Plastic-y rattle or metallic rattle?

[ginnai]

Exhaust - The vibration does make sense if the flex pipe is cracked. Would you just visually check for cracks?

Rotional - I should have mentioned that the car does not need to be moving, but the engine does have to be under load. It sounds metallic (which is why I am quite a bit more concerned about this noise).

Thanks!

[Skippy]

Have you checked the belts for cracks or any wear?

[Noisy Crow]

Since it's doing it while the car is stationary.... your mechanic should be able to track the source down using a stethoscope (or by using his favourite large screwdriver as a stethoscope). You could do that yourself, but you run the risk of being impaled by the screwdriver.....

[ginnai]

@ Skippy- The belts have no cracks or visible sign of wear.

@ Noisy Crow - I was told that he was unable to find the source using a stethoscope, but the screwdriver is a good idea. Whatever is rattling will be moving, so if I can get a screwdriver on it... I should be able to feel it. Apart from any risk of impaling/ sticking the screwdriver into a moving part, that seems like a good idea.

Can you think of anything that changes (position/ frequency/ etc) with rpm, especially under load? The prime candidate was the belt tensioner, but I have fully eliminated that. I have never seen one of these engines outside the car, so I am not sure what else is on the passenger side. My biggest fear is that a part will fail and take something else out in the process. It seems unlikely, but just trying to prevent a worst case scenario.

[Donutz]

Can you post a video of the noise?

[blackm3]

rotatinal - check brake flex plate, wheels bearing( kinda soon)

exhaust - flex sheild, check mounts and or exhuast hangers

[Noisy Crow]

With the car sitting still... could be A/C clutch, tensioner, water pump...... hmmmm failed motor mount might do it. If the goodness leaked out you could be getting metal to metal contact.......

[Skippy]

+1 on the motor mount.

[ginnai]

i will post a vid of the noise.

[Axela.Noir]

a) this rattle from the passenger side, where is it coming from can you tell which area? front or rear? wheel well, engine bay?

b) exhaust noise, can you tell if it is coming from under the car? front or rear? mid-pipe, muffler side or from engine bay?

if you can answer some of those questions, maybe we can help you narrow it down...

[ginnai]

a) it is coming from the engine bay

b) the exhaust noise seems like its coming from right up near the engine. it may be the flex pipe, since that is about where it sounds like its coming from

sidenote - it is raining very hard, which makes it hard to hear when i tried to make a vid... so i may do that later tonight/ tomorrow.

[ginnai]

http://www.youtube.com/brentonnmurray#p/a/u/0/zRwd9nbVTRk

this is a video of the noise. the camera is focused on the belt tensioner, but bear in mind i have tried replacing it... and it did nothing.

thanks!

[Skippy]

Hard to really tell noises apart in the video. Everything blends together when recording loud objects like engines. Have you checked the motor mount? Any cracks?

[ginnai]

I thought it would be difficult, but worth a shot. The motor mounts seem fine, no leaks or tears that I can see.

[Donutz]

Try spraying the belt with water and see if the noise changes. Is the noise the same now as it was before you changed the tensioner? I don't hear any rattle, but I hear some belt noise, which I assume could be the belt, the tensioner, or something pulley related. It could be that the sound isn't translating well through the video though, so I might be way off.

[ginnai]

Yea, it is hard to really hear it in the video. The noise is identical to what it was before the tensioner was replaced. Rattle may have been the wrong word, it sounds almost exhaust-ish. I may try to check the EGR tubing for leaks or the manifold for a gasket problem.

[Skippy]

How long has this noise been present?

[ginnai]

probably about two months, but in miles it is only about 500. I live close enough to work, so I have just been biking (until I get this resolved).

[Axela.Noir]

a) it is coming from the engine bay

b) the exhaust noise seems like its coming from right up near the engine. it may be the flex pipe, since that is about where it sounds like its coming from

sidenote - it is raining very hard, which makes it hard to hear when i tried to make a vid... so i may do that later tonight/ tomorrow.


engine bay rattle - this could be a bunch of things... what could rattle on the engine bay? check the exhausts heat shield, strut tower bar, anti-sway bars linkages and mounts, motor mounts, accessories, loose battery holder, etc... basically anything that might be loose or anything that's hitting something that is not supposed to hit.

exhaust noise from under the hood - check the entire exhaust system, pipings, catalytic, gaskets, donuts, flanges, holes, cracks, joints not sitting flush, etc...

hope this helps you pinpoint the problem.

g'dluck!

keep us updated!

[ginnai]

thanks for the suggestions. it is really embarassing/ annoying to drive down the road with a car that makes that sounds... i will keep on it and eventually something will break or i will figure it out. i appreciate all the help!

[McGuyver_3]

sounds to me like your power steering pump. When the pulleys go bad they start making those noises. Could be the alternator to though. Take the belt out completely and check the pulleys for all the other components mannually