[nconiall]

EDIT: Solved - changed the glow plugs and this appears to have solved the issues described below. I probably should have listened to what the fault codes told me but I'll leave the thread here for anyone who has similar issues.

Hi all,

My 2012 F30 320d (nearing 90k miles) will shake a fair bit for the first 10 seconds or so on a cold start and I had this confirmed when I ran the 'Smooth running' test in ISTA+. Here I see injector 4 (which is cylinder 2) exceeding the normal correction quantity during this time and I have actually noticed ticking upon acceleration as the engine warms up. The ticking mostly goes away once the engine is at temperature, but in some cases if I listen out for it, some can still be heard upon acceleration.

Fault code wise, I have two, and both relate to glow plugs:

242200 (SAE: P0671) Preheater plug, cylinder 1, activation: Preheater plug resistance outside specification
242400 (SAE: P0672) Preheater plug, cylinder 2, activation: Open circuit

Maybe a stupid question but can a dodgy glow plug in cylinder 2 be causing the cold-ticking/start-shake? I'm leaning towards this being an injector on its way out but wanted to cover all bases. If there is anything in ISTA+ that might help rectify these issues, please let me know (before I get them all replaced).

Other than that the engine still appears to run fine during my commute (getting ~60mpg at cruising speed of 60mph despite apparent injector issue).

I googled the issue for shaky starts and topics ranged from "it's normal" to "BMW performed a software update for the cold-start timing". The latter I would look to do but my brother has an identical car (only a 318d vs my 320d) with the same software (I-level) and his does not have the shake. But apologies if this has already been asked a million times.

All in all, everything does work fine but I'd like to catch anything before it goes wrong.


Any advice appreciated (or any recommended threads that I missed).


E: Sorry, I should clarify that by shaky start I mean vibration - as in I can feel the car shaking almost side to side during those first 10 seconds or so.

E2: A few things to add. After doing the measurement with the engine at operating temperature, the smooth running procedure proceeds fine and the values stay well within green (even when accelerating) and only move slightly, indicating the injectors are fine when the car is stationary. It seems the ticking only occurs when the vehicle is accelerating (as in literally moving, not just depressing the throttle with the clutch disengaged). I think what I need to do is check this via ISTA while the car is in motion but unfortunately, I've been running diagnostics wirelessy using a router and ENET cable, as I do not have a good portable Windows machine. I'll try and sort something out and will update should I find anything.

E3: I should also add that I now also have a Preheater plug, cylinder 1, open circuit fault now. So that's cylinder one and two with either faulty plugs or control unit (or both).

[Hypermile]

Sub'd

OP: if you don't get an answer in a few days I will try to summons the N47T guru: Enabled

[Enabled]

Hmm, any modifications done to the car at all?

I would fix the glow plugs first so you have no codes at all, then I would make sure that the injectors are all the same part number, all registered in correctly, and all sealed perfectly.

Next would potentially be making sure that the engine is not out of time due to chain stretch, since the 2012 were not yet updated with the newer chain and chain tensioner hardware.

Lastly, I would make sure the EGR function and intake tract is fine as this can greatly affect idle quality.

[nconiall]

Originally Posted by Enabled

Hmm, any modifications done to the car at all?

I believe the biggest modifcation would be the wheels - when I bought the car they came with 20" alloys instead of the standard 16" as indicated on the tyre pressure placard (the placard doesn't specify any other rim size, probably due to this being an ED version).

Other than that, there are no known modifications on the car. I did nosy in E-Sys to see if the power-reduction was removed (as the ED brings engine power down from 184bhp to 163bhp). I still see it in the VO as POWERREDUCTION but then the S843A is missing, unless this is something else for my car.

Originally Posted by Enabled

I would fix the glow plugs first so you have no codes at all, then I would make sure that the injectors are all the same part number, all registered in correctly, and all sealed perfectly.

Yeah I think so too - I see a lot of the glow plug units failing so I might look to that, although perhaps that would show all 4 failing.

I can also confirm the injectors are correctly coded (assuming cylinder 1 is closest to the front of the car) and are all the same part number. All injectors also look very clean from what I can see - no leaks that I can see but I'll check this after a drive. I secured a laptop anyway so I'll go for a drive and screen record to confirm if it is indeed injectors causing the noise.

Originally Posted by Enabled

Next would potentially be making sure that the engine is not out of time due to chain stretch, since the 2012 were not yet updated with the newer chain and chain tensioner hardware.

Engine is the N47T or N47D20C - I know this one can also experience the timing chain problems but I had read that these did have the teflon chain guides/updated tensioner? Or is there another later revision of the N47? EDIT: Nevermind, looking at RealOEM and comparing the parts for the timing system with the older N47 variant, they do indeed appear to be identical.

Anyhow, any good ways to test this? I do not have the typical rythmic whooshing noise, both at idle and accelerating. Although I'm also aware the chains can just fail without warning. I should probably look to get it replaced.

Originally Posted by Enabled

Lastly, I would make sure the EGR function and intake tract is fine as this can greatly affect idle quality.

Again, and sorry for my inexperience, any good ways to test this? As in check for EGR leaks? And carbon build-up on the intake manifold?

Many thanks for the quick response! In the meantime I think I'll sort the glow plugs first (I unfortunately won't get around to this for about 2 weeks due to a vacation but I will continue to update this thread with my progress!).

E: I'll add a video of the engine running at idle to perhaps identify any timing chain issues. I recorded at the wheel well as I believe this is where it is most audible (if not, please let me know)? Anyway, I don't believe I can hear the characteristic whoosh whoosh noise that I've heard in other before/after videos.

I also recorded a video driving but unfortunately this didn't come out too well - the noises I can hear myself don't come out too well in the recording, so I'll retry if I can before getting the glow plugs replaced. Here is a video on YouTube anyway which I'm near certain is identical in sound to what I am hearing in the cabin (the noise at the 38 second mark, and recurring noises like this beyond):

In their case it is indeed a dodgy injector - so I'll look to that after glow plugs are replaced - will keep you all updated.

[nconiall]

Hi all,

The glow plugs have since been changed over and the car no longers shake. Granted we have had warmer weather over here which would almost certainly make it seem that it's been fixed but today was pretty chilly and once again the engine started smoothly and without vibrations (the car would actually always shake on a cold start before, regardless of ambient).

As for the 'ticking' or 'rattling', it appears to be still there but much diminished - possibly caused by the warmer weather. I'll try and get around to a late night drive on a cold start to see if I can replicate similar noise levels as before (and monitor the injection correction levels to ascertain if the noise is coming from the injectors).

All in all, the car does start and run pretty smoothly and is fault-free (all green). My local indy also quoted £1,060 for a timing chain replacement, which I will aim to do before 100k miles (just ticked 90k today) although preferably earlier considering that they can just snap without warning.

E: My ticking has since stopped, in both cold and warm weather.

[capt_slow]

ISTA has a test plan for the injectors to narrow down if vibrations are caused by them. I think it's called Smooth Running Control. Give it a try as it's pretty simple to do and gives you measurements of each injector.