04 C230K 94k miles RPM drop when coming to a stop
Thread Starter
Member
Joined: Aug 2016
Posts: 158
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From: Seattle
2019 GLC300 4matic, 2019 C300 4matic, 2018 C300 4matic, 2009 C300 Flex, 2004 C230 Kompressor
04 C230K 94k miles RPM drop when coming to a stop
I noticed when im slowing to a stop at the light or something i get this sudden one second engine shake and rpm drop and a second later it corrects it self. So far i cleaned TB and MAF, replaced spark plugs, checked all the visible hoses for leaks.. the only code on OBD2 was P0620 but i think its unrelated. If anyone had this issue before I would appreciate any input on what to look for next 
Thanks
Thanks
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Joined: Jun 2002
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From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Yup. I had that. Leaking brake booster. As in vacuum leak. pop the hood and see if you hear a hissing sound. the new one will cost you an arm and a leg but you can get a used one cheaply.
The service DVD said you had to remove the whole master cylinder to get to it, but I have my mechanic do it because I thought it would be too difficult for me, but in the end he did not remove the master cylinder, he just pushed everything out of the way. It did require removing the windshield wipers and all the parts around there.
If you do decide to try to purchase a used one, any c class brake booster will do. In typical Mercedes Style the stamp many different part numbers on the brake boosters. none of those part numbers appears in their parts catalog comma as they consider it a assembly and assign it an entirely different part number than what stamped on the part. If you have any questions PM me
The service DVD said you had to remove the whole master cylinder to get to it, but I have my mechanic do it because I thought it would be too difficult for me, but in the end he did not remove the master cylinder, he just pushed everything out of the way. It did require removing the windshield wipers and all the parts around there.
If you do decide to try to purchase a used one, any c class brake booster will do. In typical Mercedes Style the stamp many different part numbers on the brake boosters. none of those part numbers appears in their parts catalog comma as they consider it a assembly and assign it an entirely different part number than what stamped on the part. If you have any questions PM me
Last edited by C230 Sport Coup; Sep 27, 2016 at 02:14 PM.
Thread Starter
Member
Joined: Aug 2016
Posts: 158
Likes: 4
From: Seattle
2019 GLC300 4matic, 2019 C300 4matic, 2018 C300 4matic, 2009 C300 Flex, 2004 C230 Kompressor
I do hear hissing when engine running coming from EGR valve area, is that where brake booster located?
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,263
Likes: 169
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
? You can't spot it?
Drivers side, goes right through the firewall, attached to master cylinder, near the fuse box and ECU.
http://www.ebay.com/itm/2004-Mercede...RXEWNN&vxp=mtr
Drivers side, goes right through the firewall, attached to master cylinder, near the fuse box and ECU.
http://www.ebay.com/itm/2004-Mercede...RXEWNN&vxp=mtr
Thread Starter
Member
Joined: Aug 2016
Posts: 158
Likes: 4
From: Seattle
2019 GLC300 4matic, 2019 C300 4matic, 2018 C300 4matic, 2009 C300 Flex, 2004 C230 Kompressor
I really cant, all the hoses and everything seems to be intact. How does yours sound when its running, does it sound remotely like hissing when you listen close to EGR? Also, i noticed the 1 sec engine shake and RPM drop is more noticeable when heater is on...
Last edited by dboyrusky; Sep 29, 2016 at 03:21 PM.
