NevoBMW320i Posted January 23 Share Posted January 23 Hello, my 2011 320D with the N47 engine has developed a problem that only occurs after the engine has been off for a while, such as overnight or after a 12-hour shift. Basically, it runs rough on first start up for about 30 seconds to a minute before settling down. I believe it is misfiring because the dash RPM needle drops (it doesn't go above 800 rpm) and dances between 600 and 800 rpm. I can feel the car is shaking at idle, and when I rev the engine. When the car is warm, it pulls and drives really well, and if I restart the engine, I have no problems. I wait for it to settle before I drive home. My EGR had continual EGR-related problems, so I replaced it with a genuine BMW, changed the mass air flow with a genuine sensor, and replaced the glow plug on cylinder 1 with a Bosch glow plug because it had a glow plug actuation fault. As of right now, I just have the brake vacuum sensor as a fault code. Is it possible that this injector is acting strangely when it's cold? The car may have the original injectors because it has 211k on it. Cylinder 1's values were bouncing around more erratically than the others during startup, but they settled down when the rough idle settled and the results showed that everything was within the normal range. Any suggestions or other things I could check for? I ran a rough running test and looked at the injector correction values. Regards Quote Link to comment Share on other sites More sharing options...
Black_raven Posted January 23 Share Posted January 23 which trouble codes are returned. Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 Unfortunately, there are no fault codes. I believe this is because it resolves the issue on its own. Thank you. Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 It always seems like a misfire when starting cold, but it will start normally once heated. Quote Link to comment Share on other sites More sharing options...
coolguy Posted January 23 Share Posted January 23 most likely the module and glow plugs Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 Hello, I fixed the glow plug issue I experienced on cylinder 1 last year. Just in case, I also replaced the module before replacing the glow plug. Thank you. Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 Additionally, since replacing the glow plug, I have not experienced any glow plug faults. When I had a glow plug fault on cylinder 1, the system threw a code even though the glow plug heated up. This suggests that the system is highly sensitive to glow plug faults. After I replaced the glow plug, the fault vanished and has not returned. Thank you. Quote Link to comment Share on other sites More sharing options...
colinallcars Posted January 23 Share Posted January 23 Does it emit a sickly sweet white vapour from the exhaust on those cold starts? My N57 turned out to be a glow plug controller and ran rough until it warmed up. According to my understanding, it maintains the glow plugs burning to even out combustion until the chamber is sufficiently heated to continue operating smoothly. It has to do with diesel. Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 This is something I haven't checked, so I'll have to get back to you on that. Thank you. Quote Link to comment Share on other sites More sharing options...
Rudy7831 Posted January 23 Share Posted January 23 Given the mileage and the fact that it only occurs when cold, it does sound like a sluggish injector. That is backed up by the cycle 1 correction jumping. Before spending a lot of money, it's worthwhile to check the glow plugs and controller as well as any hoover or air leaks. Quote Link to comment Share on other sites More sharing options...
NevoBMW320i Posted January 23 Author Share Posted January 23 Since I can code them myself and had all of the injectors removed last year to replace the valve cover gasket, I might get the four old injectors I've seen online for less than £50. Fingers crossed Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.