S320 cdi Missfire / smoke

Page may contain affiliate links. Please see terms for details.

GTT

New Member
Joined
Jul 7, 2022
Messages
5
Location
Yeovil
Car
e350 cdi c207
Hi guys, few days ago got a 2007 320cdi S class.
1st problem, steering pump and belt, bought new ones but have a bigger problem that needs solving.
Cold start is very rough, shakes very badly and sounds like a missfire? when it warms up seems to be a little better, but on hard acceleration sounds like a volvo d5, judder and smokes from time to time, not runing properly on all 6 cyl.
I assume it must be a bad injector?, will it work to measure with 6 syringes and see how much I get on each injector? Any help will be really appreciated. Thank you.
 
Hi guys, few days ago got a 2007 320cdi S class.
1st problem, steering pump and belt, bought new ones but have a bigger problem that needs solving.
Cold start is very rough, shakes very badly and sounds like a missfire? when it warms up seems to be a little better, but on hard acceleration sounds like a volvo d5, judder and smokes from time to time, not runing properly on all 6 cyl.
I assume it must be a bad injector?, will it work to measure with 6 syringes and see how much I get on each injector? Any help will be really appreciated. Thank you.
Really need to get diagnostics checked before you start spending any money; preferably by someone who knows these engines. If you bought the car from a dealer, I'd take it back and have them sort it.

Ernie
 
  • Like
Reactions: GTT
Hi Ernie, thanks for your time, usually I do fix my own cars but haven't bought any tech for Mercedes yet. Think I found the problem. Have some seals from a 270cdi and by looking online it seems are the same specs as on the 350cdi, bolt and washer.
 

Attachments

  • 295382922_1621576411575596_4039456626272129626_n.jpg
    295382922_1621576411575596_4039456626272129626_n.jpg
    87 KB · Views: 17
  • 290001885_1066400524308895_440069672079230489_n.jpg
    290001885_1066400524308895_440069672079230489_n.jpg
    194.2 KB · Views: 16
In addition it could be rail pressure variation problem, you can do spill leak off test for injectors, but unfortunately you will need diagnostics to find out electrical correlation values to get more insight whats happening inside the injector. All test should be done at cold engine, if thats problematic working point.
 
Hello and welcome .

"I assume it must be a bad injector?,...."

Personally I would assume nothing when fault finding and would prefer to read the codes (unless the problem was visible to the naked eye) . When owning an MB of this vintage (mine is 2006) having your own code reader is the best bet, many on here get along fine with an iCarSoft MB , they are quite cheap and it can often pay for itself the first time you plug it in. It also reads other car apart from MB.

You say you might have found the problem then show us a bolt and copper washer . What is this bolt for ?

Please let us know how you get on 👍
 
One thing you can be certain of - the PCV in your pic needs changing as it appears to be leaking oil. They degrade over time and the rubber diaphragm goes hard and splits. You will get an updated/improved orange seal at the turbo end. 10 min job to replace and mine ran better after changing mine (on an OM642)
 

Users who are viewing this thread

Back
Top Bottom