snapshackle

MJ50

moved to C450/C43 forum...

Cosworth2000

Hmm.. i hear the same thing but I can't tell where the sound is coming from so I just turn up the music.

cenzo86

Find the seems where the dash panels meet and shim some felt between any gaps. Especially during the cold months the plastics squeaks where they rub.

eagle_lex

This might be the fan motor for the AC/heater blower. Just a guess. See if it comes and goes based on temp. My old e350 had a chirp at about fan speed 2. Any higher it got drowned out or it might have stopped idk. Fan motors use to be a rather common issue. I think it was about 400 or 500 bucks to have MB fix. I didnt know what it was when it was under warranty. If its the motor it will get worse slowly.

snapshackle

Thanks for the response. This has been going on since I got the car but I can not get it to misbehave on request. Dealer never hears it. Irritating. Thought for a while it might be leaves in the blower, doesn't explain the ping pong L to R effect. tried changing the air flow direction or selecting the defrost. No joy. one day I'll be driving by the dealer at the very instant this 'squirrel in the attic ' is scratching the a/c system. Which is just slightly better odds, I think, than hitting Lotto. Was hopping this was not a rare occurrence. Thank you again.

kevin-L

I've noticed some similar scratchy/rattly sounds that seem like they're coming from inside the dash over on the passenger side. I initially thought it was the glovebox or something inside it, but I've ruled that out now. I've also noticed it mostly on colder days, usually within the first 10 minutes or so of the car running, but changing settings on the climate control or turning it off doesn't seem to affect it. If you find out what it is be sure to post here.

rustybear3

Sounds like the doors opening and closing on the AC/heater unit. Best bet is to try and capture it by phone if possible.

MarcusDubya77

This..most cars have some sort of venting system that open and close or even swing side to side like window mounted A/Cs of yore....

MatthewJ

Not to add more confusion to this but could be hearing high pressure fuel pump if its at a specific RPM (1700ish?) as there have been a few complaints on that. Also on the waste-gate rattling at idle and low RPM. I think i have this and it does sound like crickets in a box or marbles chattering around. Not sure there is a fix for it and i think its only the one on the passenger side.

snapshackle

Thats a great idea. Feeling stupid not to have thought of it already. I’ll give it a shot. Betting they will still need to reproduce it themselves. Thanks

SeaCoupe

I still lurk. Seacoupe is getting parted out. I thought about doing another 5 speed Coupe, but I'm just not feeling it.

E63Sauce

Ya phone vids are super useful - to any shop - you can just put it on youtube and link it to whoever is working on your car.

doctorpen

Don't mind me, commented on a related post instead of the actual post I was looking at, new user if you can't tell