S550 idle problem
Newbie
Joined: Apr 2012
Posts: 10
Likes: 0
From: California
2005 C230, 2007 S550
Just wanted to let you know, I had the same exact symptoms. When in traffic, or at a stop - the car would idle rough when going 1-2 mph. Check engine light came on about 2 weeks later. Took it to MB and the return code was p303. Misfire on the #3 cylinder. They said it's caused by a faulty exhaust valve. $8000 job, but my warranty is covering it. Well, atleast some of it. MB quoted them 22 hrs to fix, and warranty company is saying 14 hours going by Mitchell Labor guide. I have to pay the difference if they don't agree. My car is still in the shop, should get it back next month. Hopefully this info helps you out. No one knew why my car was idling rough until the check engine light came on. You can read my thread below if you like, although in my thread I didn't post any symptoms.
https://mbworld.org/forums/new-s-class-w221/445386-2007-s550-bad-cylinder-new-post.html
https://mbworld.org/forums/new-s-class-w221/445386-2007-s550-bad-cylinder-new-post.html
Thread Starter
Newbie
Joined: Jul 2011
Posts: 14
Likes: 0
2007 s550
Sorry guys I havent been on forum lately but as far as my car it still has the problem and I been to the dealer so many times they can't seem to find out what's wrong with the car because they basically just work off what the computer tells them
So I have to wait until my check engine light comes on,I have had this car for over a year with the same problem and no check engine light came out till this day.mb service sucks!
So I have to wait until my check engine light comes on,I have had this car for over a year with the same problem and no check engine light came out till this day.mb service sucks!
Senior Member
Joined: Jun 2004
Posts: 382
Likes: 4
From: LI, NY
(1960) 300d, S550 AMG S500 S600 560SEL
Sorry guys I havent been on forum lately but as far as my car it still has the problem and I been to the dealer so many times they can't seem to find out what's wrong with the car because they basically just work off what the computer tells them
So I have to wait until my check engine light comes on,I have had this car for over a year with the same problem and no check engine light came out till this day.mb service sucks!
So I have to wait until my check engine light comes on,I have had this car for over a year with the same problem and no check engine light came out till this day.mb service sucks!
MBWorld Fanatic!
Joined: Mar 2011
Posts: 1,315
Likes: 4
E55, SL63, ML550
Just wanted to let you know, I had the same exact symptoms. When in traffic, or at a stop - the car would idle rough when going 1-2 mph. Check engine light came on about 2 weeks later. Took it to MB and the return code was p303. Misfire on the #3 cylinder. They said it's caused by a faulty exhaust valve. $8000 job, but my warranty is covering it. Well, atleast some of it. MB quoted them 22 hrs to fix, and warranty company is saying 14 hours going by Mitchell Labor guide. I have to pay the difference if they don't agree. My car is still in the shop, should get it back next month. Hopefully this info helps you out. No one knew why my car was idling rough until the check engine light came on. You can read my thread below if you like, although in my thread I didn't post any symptoms.
https://mbworld.org/forums/new-s-class-w221/445386-2007-s550-bad-cylinder-new-post.html
https://mbworld.org/forums/new-s-class-w221/445386-2007-s550-bad-cylinder-new-post.html
Cool lagoon, where were you on this one. Is the best you can say is check electrical, fuel and mecanical?? Wow go mop the floor bud.
Senior Member
Joined: Jun 2004
Posts: 382
Likes: 4
From: LI, NY
(1960) 300d, S550 AMG S500 S600 560SEL
So a compression check would have revealed this problem, then further steps to determine the exhaust valve seat probably was wallowed out.
Cool lagoon, where were you on this one. Is the best you can say is check electrical, fuel and mecanical?? Wow go mop the floor bud.
Cool lagoon, where were you on this one. Is the best you can say is check electrical, fuel and mecanical?? Wow go mop the floor bud.
hahahahhahahaha.
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Senior Member
Joined: Jun 2004
Posts: 382
Likes: 4
From: LI, NY
(1960) 300d, S550 AMG S500 S600 560SEL
Super Member
Joined: Apr 2007
Posts: 561
Likes: 2
From: New Mexico
2014 E350, 2012 SL550
Thread Starter
Newbie
Joined: Jul 2011
Posts: 14
Likes: 0
2007 s550
Well my warranty expired and nothing was fixed they told me they can't fix it unless there stupied computer shows them the problem.i will be taking it to a local mechanic to see if he can finally solve the problem.as for that valve you guys are talking about I think that was already replaced.seems that wasn't the problem.
Member
Joined: Jun 2018
Posts: 146
Likes: 31
From: Stuart, Fl
2008 S550
I stumbled on on this post and my car has the identical symptoms occasional rough idle and this strange down or up shift which feels like somebody has rear-ended you. So I had to post and see if this was ever resolved I realize it is quite old. Btw, my car is an 08 S550 with 160k miles. Well maintained however. Thanks in advance
Newbie
Joined: Dec 2016
Posts: 2
Likes: 0
S55
I stumbled on on this post and my car has the identical symptoms occasional rough idle and this strange down or up shift which feels like somebody has rear-ended you. So I had to post and see if this was ever resolved I realize it is quite old. Btw, my car is an 08 S550 with 160k miles. Well maintained however. Thanks in advance
Member
Joined: Jun 2018
Posts: 146
Likes: 31
From: Stuart, Fl
2008 S550
Wow this is an old thread! I don't even have that car anymore I have a newer S 550 but yes I was able to resolve the problem total Hall of Fame repair. So literally all I did was clean the throttle body I disassembled it and found that the lower portion was completely choked with oil from years of residue building up. In fact there was so much you could hear it gurgling when I removed the plastic duct leading to it. I just used a rag and carburetor cleaner to wipe it out and clean it thoroughly and like magic it fixed the problem. It's a little tricky you want to do it on a cold car so you don't burn your fingers. You remove your air box you remove the mass air flow sensor and then you remove a small little piece of plastic duct and with a light and a mirror you can see the throttle body and in my case there was oil residue that had built up. It literally ran like a brand new car afterwards. And then I wound up doing this as a maintenance every year thereafter to keep it running well
Newbie
Joined: Dec 2016
Posts: 2
Likes: 0
S55
Wow this is an old thread! I don't even have that car anymore I have a newer S 550 but yes I was able to resolve the problem total Hall of Fame repair. So literally all I did was clean the throttle body I disassembled it and found that the lower portion was completely choked with oil from years of residue building up. In fact there was so much you could hear it gurgling when I removed the plastic duct leading to it. I just used a rag and carburetor cleaner to wipe it out and clean it thoroughly and like magic it fixed the problem. It's a little tricky you want to do it on a cold car so you don't burn your fingers. You remove your air box you remove the mass air flow sensor and then you remove a small little piece of plastic duct and with a light and a mirror you can see the throttle body and in my case there was oil residue that had built up. It literally ran like a brand new car afterwards. And then I wound up doing this as a maintenance every year thereafter to keep it running well
