ash_cpe

Hi All,

I keep having troubles with this car, lately I am having a popping noise from the undercarriage while driving at slow speeds, stopping at a red lights, even parked and turned off. Took it to the dealer, the repositoned the exhuast and they said that should take care of it. Tonight I got the car back and still getting the same noise. Anyone having similar issue? please advise.

Thanks!

ash_cpe

Took the car to dealer today, and they said they tested 2 e class loaners with about 12000 miles on each and they have the same noise. Noise produced from exhaust when it gets warm it expands and starts hitting a metal plate underneath the car.... They are going to contact MB TAC with a case regarding that. Hope will hear back in few days. Does anyone has similar issue?

Green Pinto

i have the EXACT same issue with my SL. took it to the dealer yesterday and they basically charged me $167 for a car wash because they couldn't figure out where the noise was coming from either. they wanted to do an audio test with further diagnostics that would run me another 5-600 dollars or so. i said no and took the car back.... i work in the science/engineering field so i tried to do some research and this is what could be the problem..

1. fuel leaking into the cat convertor and igniting intermittently.. this produces a popping noise. it would also spike up the temperature of your cat leading it to fail over time (very expensive). plus you'd have to find the source of why your fuel is leaking.

2. dealer said they think it's a bad strut (i have hydraulic ABC suspension) that is releasing pressure every once in a while. i personally don't think this is it. i've had a bad strut before and it didn't make any sounds like this. plus if it was bad.. it should also leak hyd oil which it's not. and now hearing that you have the same problem without ABC suspension.. it leads me to believe even more that this isn't it.

3. possibly some undercarriage braces that are adjusting under torsion/tension as the car is moving, warming up, cooling down, etc...

4. and like you said.. the dealer also told me that it could be the exhaust hitting or rubbing up against the heat shields as the car warms up and cools down causing it to make noise. i'm hoping this is all it is. easy/cheap fix.

anyway.. i plan to lift my car soon and take a look for myself. please keep me posted on what you find out because this is freakn annoying. and i would like the both of us to catch a potentionally expensive problem before further damage may happen.

but yeah... popping noise every once in a while.. especially during heat up and cool down of the car... even when the car is completely off and just sitting there. i also noticed it pops almost every time i hit around 60 mph. which could mean it's the suspension again since my car drops an inch by computer at 60.

eff.. i dunno.

Green Pinto

oh and i've also heard it could be the control arms/worn bushings

ImInPA

A couple things to have the dealer check: 1) a service bulletin about loose fitting undercarriage panels; 2) popping noise from seat tracks (can sound like it is coming from under the car). I hate pops, squeaks, and rattles. Had a couple in my E but all fixed now (at least for now). The exhaust hangers sounds like a likely culprit too.

ash_cpe

Thanks all for your replies. Mercedes thought it's from metal bracket holding the 2 exhaust pipes by the engine. After going back to different dealer for multilbe times. We were able to pin point the noise and found out it was coming from one of the exhause heat shields by the drivers side. The technician ( great guy) repositioned the heat shield on Thursday. Didn't pop since. That was an easy one that took me 8 delaer visits! And the heat shield that was popping caused by in-experienced tech at a different dealer who checked my car earlier this year for steering connection fitting recall and the poping noise started since then.

I had few issues with my car since day one and most of them were dealer related. Mercedes quality is great but unfortunately service no good at most dealers in my area. I had worked with multiple dealers in my area. First dealer they fly over speed bumps driving your car, arrogant, they think you don't know anything about MBs. 2nd dealer carved one of my car wheels with a curb. 3rd dealer caused the popping noise that made me go to MB dealers for about 8 times! My advise about noises if a you don't have a good dealer, try pin point them your self and then go to the dealer. Now I think I found a great dealer who works with a passion to please their customers.

Green Pinto

AWESOME! sorry about your luck with the dealers. i've had bad experiences with them, too. good to hear your fix was a cheap and easy one. hopefully mine is the same. after all this research, i decided to go to an independent muffler shop tomorrow with great reviews to have him check my shields and exhaust. research led me to fall upon deleted resonators in the exhaust system and to have that done now, too.

K-A

Yikes! Please tell me you don't live in the SoCal area?!

Ctrl+alt+Elite

i'll definitely remember this thread, i'm at 10800 miles and super-duper OCD when it comes to noises. Thanks for the heads up

ash_cpe

No I don't live SoCal

ash_cpe

If my car wasnt under warranty I would definitely go to independent shops for repairs. Let us know how things go. GL

Green Pinto

alrite guys.. i just came back from FANTASY MUFFLER in Buena Park, CA for you SoCal guys... turns out the exhaust was lodged up closer to my undercarriage from lifting the car incorrectly by either my mech, me, or the tire shop...

the guys at FANTASY lifted my car... and popped it back down in about 10 seconds with a slight tug with a crow bar to get the whole exhaust system seated back in place. VOILA! Popping GONE! So yes.. it was the resonator heating up against the heat shields. these guys are DOPE. SUPER NICE.. didn't charge me a dime... the guy's name is Steve and he literally told me to get outta here before I could even offer anything to pay.

If you guys have ANY exhaust issues.. i'd highly recommend seeing him. hard to find good honest people these days..

he also found two holes in my muffler where my exhaust hangers were attached to before falling off and said he'd just patch em up and reweld it all back together for me when i go back in tomorrow to have my resonators deleted.

thank you to everyone on this thread and hope this helps out a lot of future people from costly repairs and a wrong diagnosis.

see ya guys =)

ash_cpe

Fantastic! Glad it's fixed, enjoy!