Canica

I would be very grateful for your help. After having the air filter box changed at my dealership by my mechanic, I started hearing a noise like a loose sheet of metal in the engine area, after the car had run at idle for about 10 mins. After much checking and discussions, my mechanic finally heard the noise and said it was caused by loose flaps in the sport exhaust. Apparently they cannot be adjusted and a new exhaust is required. Problem is that I have already invested around US$57K in the car. I love my car and it is back to nearly perfect, but the idea of spending an additional US$6,200.00 is hard to accept. Any suggestions would be greatly appreciated. Best.

terbiumactivated

Are you saying the noise was never heard till you had the air box changed? If so that's a strange coincidence since he just finished wrenching on it. Is the mechanic sure he has diagnosed said noise properly? Assuming his diagnosis is spot on and that there is no way to improve the function of the valves you might consider for the time being fixing them in position either open or closed with a reversible repair. PS Why was the airbox changed, did someone modify the old one?

Canica

terbiumactivated; thanks for your reply. That is correct. I first noticed the noise after the airbox was changed. It is not a terribly loud one, but I tend to notice such things. Previous owner had a K&N installed and they broke the area where the screws that close the acsess lid are located. For now, the valves are fixed in the open position. It was me who noticed the noise, but each time I took it to my mechanic for him to hear, I could not make the noise to appear, until finally the mechanic was able to hear it after the car spent the night and was started up cold and let run at idle for about 10 mins. The car also made another different, but still not so loud noise, after an extended run in hot climate at relatively high speeds No codes or other symptoms or effects. With the valves temporarily fixed in the open position, the car feels much faster but with noticeably less torque, and it revs much quicker. I prefer the original functionality. My car is a 6 spd. manual. Thanks!

Waxer

Valves are operated by a vacuum. It could be that one of the vacuum valves are faulty. I would take it to another Porsche dealer and have it diagnosed. I can't imagine having to replace an entire system because a valve or flap is bad.

I would also call Cantrell to see if you can ship your exhaust system to them for repair. My Spyder does not have sport exhaust and I am considering sending my exhaust to them to modify so that it sounds like sport exhaust full-time. I do not want to spend $6000 to install PSE

Canica

Thank you Waxer for you response. Good ideas which I will probably try. Problem down here in Mexico City is that there are not that many dealerships. Indy shops that specialize in Porsche are non-extant and almost all mechanics are either ignorant and /or not trustworthy. As mentioned, my problem is that although the valves are fully functional and operate correctly, they vibrate causing the noise at idle. I am not sure that getting rid of the noise is worth $6K. Thanks again. Best.

terbiumactivated

Canica, not to speak for waxer but I don't think he was suggesting a 6k change out of the exhaust. I think he means the valves themselves can be checked for proper actuation and a repair other than replacement might be effective. If that is what he meant I tend to agree with that. He also suggests removal and shipment to another repair center, not a bad idea if you have a garage to leave it in and the skills to disassemble the exhaust. I don't mean any offense when I say this but I'd want a second opinion other than one from a Mexican Porsche wrench at one dealership.

Canica

terbiumactivated; thanks for your reply. I think I understood what Waxer suggested and his reasoning. A repair/adjustment of the valves so they do not rattle is exactly what I would be looking for; however, going to another mechanic in another dealership will not be easy. In my neck of the woods, your really have to build a relationship with mechanic before you can trust him. I will be calling Cantrell to see if they would work on my exhaust. I can have it taken off by my mechanic and the car can be kept at the dealership. The dealership, by the way is the most important in Mexico. I have enjoyed seeing there 4 of the 8 918's in Mexico being serviced along with a Carrera GT and many GT2 and GT3´s. You have not been offensive in any way, and I appreciate your comments. Best.

Waxer

Correct. Not suggesting a $6k replacement.

Call Cantrell.

mbogoscars

FWIW, I have a 2008 CS (44k mi) with sport exhaust that developed a rattle in the exhaust about 10000 mi ago. Most noticeable at idle and occurs only in normal exhaust mode. The rattle goes away completely in "Sport" mode. My mechanic recommended simply driving in sport mode if it bothers me, versus new exhaust replacement.

I'm certainly interested in repairs if they are possible.