2003 Boxster rear end noise
 

Hi,new to forum at just picked up a 2003 50km's boxster 4 full year warrnty.I also own a 1980 911SC and still runs great.I think this topic been coverd before and hopeing its the same thing as others.When i was looking to buy this car i went over it few times driving it,listening to engine driving it again and sounded quite,smooth clean running.I was going to take it to my porsche mech. to have it inpected but decided not to because the car's in mint shape 1 owner and sounded great and thought i guess worse thing would be is a new clucth.So next day when i picked it up i drove it around and not sure if it happens when engine is at normal operatering temp. but theres a wierd loose metal hitting metal, buzzing,rattleing sound coming from the rear end as u release the gas petal down shifting and acceralte up the gears just normal driving.Its some times happens and sometimes not.Someone on forums saying heat shields on the exhuast hiting and is something i can do myself? Also is true engine cant be rebuilt? planning to keep car long time. thxs

Congrats on the new car! Noise could be lots of things. Including damaged cats.

This is a mechanical engineers (not an experience Porsche mechanic) crack at this question:

Vibration responses happen at different frequencies caused by part rotating at different speeds. Knowing a what speed (or frequency) you hear the vibration isn't normally much help because you would need an in depth structural analysis to figure it out.

One trick that could help you at least hear the noise better is to drive beside the wall of a building. That will reflect the sound much better and hopefully help you figure it out. I do this when I am test driving a car, it really highlights problems. Or if you can reproduce the vibration at low speed, have someone sit in the rear boot.

Adding mass or stiffening up the part will change the frequency of vibration. If you think it's the heat shield, you can tape it up (as a test) to see if the frequency changes. If it does, you found the problem. It might be trial and error until you find the culprit.

I have the same problem. I have a 03 boxster as well. It doesn't seem to be a serious issue since it's not setting off any light on the dash. It only happens at idle...or at least that's the only time I can hear it. It sounds as if the exhaust pipes are cooling down and the metal is contracting...but that's not the case since it goes way when I turn the car off.

Most have told me its bad cats but it just passed emissions so I don't think that's the problem. I just got my extended warranty so I'll take it in soon. To me, it's not a big deal. Hopefully someone had this issue in the past.

I had the same problem. My car passed emissions, no problem. When we put pressure against different parts of the exhaust the intermittent rattle would go away. First we removed a cat heat shield but the noise persisted. Finally had my mechanic methodically check each piece of the exhaust until he narrowed it down to the front pass. cat. It wasn't completely defective(Porsche wouldn't warranty), but replacing it totally got rid of the rattle. Expensive...but no more problem.

Hi all,thx for replies.I drove it around some more and noticed it at idle too and has that sound as if from the cats. If u rev. the car just slightly at idle even on a cold start some times u can hear a little rattle,buzz noise.The thing that gets me is that sometimes it doesnt even happen and sounds nice a smooth until it starts to rattle again. So as long i dont see any warning lights on the dash it could be something minor loose or cats and would it be porsche warrnty if cats?Has 50km's.I guess it wouldnt be from the tranny if i can hear it at idle no?
I'am taking it to my porsche mech. next week but hopping i could find the problem before then.Also would it be cheaper to take it to a local brake shop to have brakes done and i supply the parts from Pelcian parts and just pay for the labour?My porsche mech. is gonea charge me $850 Canadain just for the front brakes pads,rotors,labour not sure if they need new rotors though.And for a full replacement clucth if needed $3200, that sounds right?My 911SC is around $1300.Other then those worries the car drives great in town and on the highway.Oh and one more thing where do u get those Hardtop's and how much new or used?And it just sits on top the car with specail locks? The secondary cats u can take off and have staight pipes going threw with no warning lights and it well still pass emmsions no? Fabspeed pipes.

I get something similar - a slight metal buzzing/dragging sound. Only happens at very low RPM (1500 or less) in 3rd or higher, and only if the engine is cool. Bad Cats was the suggestion here.

I have had no CELs so I dunno

I just recently made a thread about this. I had the exact same problem with my 2003. Turned out to be the heat shields in both cats. Warranty covers it though, so you can just have the dealer replace both cats.

I am starting the suspect the exact same issue with my car (see my recent post). My car sounds like you just poured a bowl of rice crispies after you run it for a while.

Does your car smell funny when you ride top-down? I couldn't smell my car, but my wife thought I smelled funny after riding in it...

Its worth asking why you have a dead cat -- what is root cause. I am reading/learning more about this now for my own situation.

By the way, my 7 year old was horrified about the "dead cats".

Understand that the emissions warranty is 7 years? So if its Cats, your probably covered. I am investigating for my own case now and will post my experiences and findings.

Cool thanks for replies again.Sounds like some kind of porsche part faulty or maybe the car being low some owners before the lastest owner has bottomed out over a speed bump or pot hole in road maybe hitting the exhuast or cats. causeing small bend or something over time the heat starts to break it down causeing the nosie to act up. Just a thought,but hopfuly not related to some kind of engine problem that shows.tells that the engine hasnt been cared for over the years which causes the cats to burn up.

So, techron & premium gas took care of my issues. Hope you have the same luck.