Noise under load.

Chaps I've started getting this noise under load. If I'm stationary and rev the engine, it sounds fine. It only happens in gear and under load. Just had the clutch, IMS & RMS done, so hopefully it's not one of them. What do you think? https://soundcloud.com/lesfield/pors...tle-under-load

Quotes source post: 11546604

Well, I listened to the clip 3 or 4 times and nothing jumps out at me. Perhaps if you stated at when times in the clip the noises occurred would be of some value? Regardless, if you say the car sounds different now than it did a while back, I won't argue. But I can only offer general advice. Whenever something is done and the car sounds different afterwards the first thing suspected is the last thing touched. For the clutch, RMS and I guess IMSB ('B' for bearing) work that was done this means the half shafts were unbolted from the transmission and the exhaust system and transmission were removed. There are a number of ways to, if you'll pardon the expression, screw up when reinstalling these items. If things are not installed correctly, for instance the exhaust, while the exhaust may not leak the vibration characteristics, the vibration harmonics of the exhaust system, the engine, in fact the entire car, can be changed. To cut to the chase, then a course of action would be to take the car back to where you had the work done and demo the noise and ask what it is and what would be the recommendation as to what to do about it.

I failed to hear anything useful in the clip as well. Is it a rattle? One of the most common offenders for noises that happen at anything above idle is cat rattle/heat shield rattle. Could also be the throwout bearing, since you just had that touched, but this is just conjecture. I'm with Macster - if it didn't happen before you spent thousands getting things fixed, take it back to the man you've already paid and get it resolved.

It is the higher pitched noise like some small bits of metal in a coffee grinder, or valve clatter. Only seems to happen when hot, wonder if it's the Cats?

Quotes source post: 11548372

Valve clatter is a cold start noise and should be brief, very brief. There should never be any valve clatter once under way with a cold, warm, or hot engine. My opinion is if you were hearing valve clatter the CEL would be on. I think you can dismiss valve clatter as a source of the noise. (Now I have to mention IMSB. I'm not at the car and even if I was I'm not qualified to make any diagnosis of this, but if you want to eliminate this long shot possibility of the noise you can drop the oil filter housing and check for any debris in the housing oil or filter element. Be sure you use a clean (spotlessly clean) drain pan. I am not being an alarmist just thorough and offer this just in case the noise is an early warning of pending IMSB failure.) With your guess of converter you are probably right. Based on my experience with my Boxster if a converter brick is loose it can buzz something fierce. Oh, it does this when hot. When cold, it can also knock about which can have one seeing $$$$ for an engine rebuild. It shouldn't be too hard to get the car checked out by a tech and eliminate the converters. If you and a tech do not find any reason to suspect an IMSB problem, if the converters prove to be ok, then as I recall you just had some work done on the car. If the noise came about after this work was done this raises the possibility something from the work is the cause of the noise. It could be something as simple as a line of some kind touching a part of the chassis/body. (Not too many days ago someone reported a sudden appearance of some noise after his car was worked on. A sanity check found that indeed something was touching something it was not supposed to touch and once this was addressed the noise went away.)

Although a mechanic should have no need to remove them during the jobs you had done, the heat shield is made from very thin gauge metal which are held by 2 screws each side. Maybe they left a screw out of one of them. If they did (and mechanics do leave screws out the lazy so and so's) that side should emit a high pitch rattle sound. They are easy to check on a cold engine. Jack the back up and feel by hand as you can't see the far screw. Good luck.