E90Post
 


 
BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > Regional Forums > UK > UK Technical Forum > Cold Start Idle issue - any ideas?



Reply
 
Thread Tools Search this Thread
      01-30-2016, 01:24 PM   #1
Phil325i
Lieutenant Colonel
Phil325i's Avatar
United Kingdom
59
Rep
1,810
Posts

Drives: E92 325i MSport Coupe
Join Date: Apr 2012
Location: UK South East

iTrader: (0)

Garage List
Cold Start Idle issue - any ideas?

For several months now my N53 has not been running right on cold start-up. Instead of idling at increased revs while the engine warms, start-up consists of an initial throttle 'blip' to about 1,000rpm, followed by engine revs sinking back to normal hot engine tick over speed (about 700 rpm).

Absolutely no fault codes showing. I'm about to remove and clean the throttle body, but anyone have any other ideas?
__________________
E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; BMS clutch stop; BMS CDV; RE g/box mounts; Saikoumichi OCC; K&N; Cyba scoops; BA diff brace; BMW Perf Exhaust; M3 rear spoiler; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof
Appreciate 0
      01-30-2016, 03:33 PM   #2
old grey steve
Colonel
old grey steve's Avatar
United Kingdom
136
Rep
2,663
Posts

Drives: 335i Coupe.
Join Date: Oct 2012
Location: UK in Hertfordshire

iTrader: (2)

Tough one to predict and perhaps as we've seen countless times the hardest ones to call

As always especially with nothing to go on, these cars usually have habitual issues even without codes, but an injector or injectors starting to just let go will display the symptoms you're expieriencing Phil, we've seen several with no faults using an borescope/endoscopy type camera which we use can show the start of the issues that an injector can cause, the way you're describing the 'blip' perhaps and it's a long shot but makes me think there could be some I burnt fuel from a leaking injector could be wrong but sounds like the blips like the cars clearing it's throat

Coils plugs and the rest of it can/are fair game too, but changing these is fairly straightforward to do and as a first port of call you could look at and inspect the plugs but chances are this isn't the offending area but perhaps it's worth going over or back over if you've been here before.

We've seen as I expierienced with mine(though I've got an N54) a leaking rocker cover gasket which leaks inwards that allows oil to bypass the plug well sleeve lightly coating the plugs as oil will travel downwards my leaking rocker cover gasket wasn't the only issue I had the cover cracked allowing oil to wealt out travel down the side and cost an injector in both cases after start up symptoms became better as I suspect the oil was burnt off.

Another issue could be the start of a fuel pump issue too where on pressure the desired mBar requirment isn't being reached hasn't quite gone as so far as to produce a fuel pressure plasuability fault but checking the pressures of the pump and low/high pressure system will shine a light on whether it's the start of an issue re this area and sadly it's not uncommon..

Smooth running tests will certainly assist and will move you in the right direction but it could be several things that alone or perhaps together can create an issue you may be expieriencing, but I suspect t you'll get several answers to the same issue .
__________________
Appreciate 0
      01-31-2016, 11:03 AM   #3
Phil325i
Lieutenant Colonel
Phil325i's Avatar
United Kingdom
59
Rep
1,810
Posts

Drives: E92 325i MSport Coupe
Join Date: Apr 2012
Location: UK South East

iTrader: (0)

Garage List
Thanks as ever Steve. I think most of the possibilities you mentioned I can eliminate:
  • Plugs are only just changed (made no difference to the issue) and looked very uniform and normal. Absolutely no signs of oil in the plugs area (or anywhere else for that matter)
  • Coils are not that old either
  • The 'blip' may have been my poor explanation. What I meant was, on starting the engine from cold it revs to 1000rpm only to immediately drop back to 700 rpm rather than remaining at higher rpm until the engine has warmed.
  • I'd be surprised its the HPFP as it's been changed under warranty and I'm getting no other issues that might suggest the pump
Could be a faulty temp sensor telling the ECU the engine temp is warmer than it is..?
__________________
E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; BMS clutch stop; BMS CDV; RE g/box mounts; Saikoumichi OCC; K&N; Cyba scoops; BA diff brace; BMW Perf Exhaust; M3 rear spoiler; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof
Appreciate 0
      02-01-2016, 10:17 AM   #4
Aragorn30d
Lieutenant Colonel
107
Rep
1,582
Posts

Drives: E90 330d
Join Date: Mar 2015
Location: Fife

iTrader: (0)

why do you think its an issue?

is it running smoothly at 700rpm or is it missfiring or lumpy?
Appreciate 0
      02-01-2016, 12:02 PM   #5
Phil325i
Lieutenant Colonel
Phil325i's Avatar
United Kingdom
59
Rep
1,810
Posts

Drives: E92 325i MSport Coupe
Join Date: Apr 2012
Location: UK South East

iTrader: (0)

Garage List
Quote:
Originally Posted by Aragorn30d View Post
why do you think its an issue?
Simply because it never used to be like this. If you listen to this cold start vid (yes, I know it's an M2) this is how my car used to rev on cold starts. You'll hear it stays at high revs for quite a while before it begins to drop down to normal idle speed. Mine doesn't do this at all - it goes straight to 'normal' hot engine tickover speed...

http://f87.bimmerpost.com/forums/sho....php?t=1217202
__________________
E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; BMS clutch stop; BMS CDV; RE g/box mounts; Saikoumichi OCC; K&N; Cyba scoops; BA diff brace; BMW Perf Exhaust; M3 rear spoiler; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof
Appreciate 0
      02-05-2016, 06:06 PM   #6
old grey steve
Colonel
old grey steve's Avatar
United Kingdom
136
Rep
2,663
Posts

Drives: 335i Coupe.
Join Date: Oct 2012
Location: UK in Hertfordshire

iTrader: (2)

Mentioned injectors on the earlier post Iput up a feww days ago but the tale below is for an N53....

on start up car runs a little abnormally and doesn't seem quite itself until it warms up then seems to settle down, cars been a little bit of problem shild of late where HPFP was a susspect and also changed was the LP & HP sensor as well, fault wise codes were devoid then may re appear, but it seems to be sproadic.

Only option left open was to think outside the box on these type of cars we have seen issues before where if you look at diagnotic codes you can be thrown off course, so we opted to do the only thing that would make sense to us and that was to look inside the bores and check out what was going on inside the engine of this N53.

When inspected cylinder 2 had visually a fair amount of carbon deposits present you could see it with out endoscopic camera which led us to look at the injector which is what we suspected, injector 2 when checked was misting fuel and when removed to visually check had as we thought signs of carbon depsoits present so we opted to look at the o2 sensor bank 1 which lies in line with injector 2 as neat fuel won't do these too much good long term




and the sensor was showing signs of fuel contamination too.

So we opted to sort the injecotr out change the 02 sensor and run the car again (we kept the car for 3 days to be safe) and post the work despite the diagnostic results being a big vague this car has been a perfect car.

Always expect the unexpected and as we are seeing from time to time diagnostic codes can or may not give you the full picture
__________________
Appreciate 0
      02-09-2016, 08:12 AM   #7
AWSAWS
Lieutenant Colonel
AWSAWS's Avatar
81
Rep
1,840
Posts

Drives: E92 FBO 335i MSport DCT
Join Date: Nov 2012
Location: Earth

iTrader: (0)

Before you do anything try resetting adaptations.

There is quite a variation between summer and winter conditions and my car itself used to behave like this before I reset the adaptations. The O2 or lamda sensors seem to get confused over time.

Take a look at INPA for this. I've not used it myself but I think it's quite straight forward. I use MHD flasher.

There's also supposed to be the reset option with the throttle which would be worth a go. This might not sort the O2 and Lamda sensors. I can't remember. I use the 1/7 option on a JB4 sometimes.

I'd try the below first. If that doesn work, then reset adaptations with INPA.

Anyway here's the procedure:

1. Insert key push start button. Do not touch brake. Ignition will now be on.
2. Press and hold accelerator pedal to the floor for 30 seconds. Do NOT release the accelerator pedal. Keep it pressed down.
3. Push the start button again. Do not touch the brake as you do not want the car to start. The accelerator pedal is still pressed down.
4. Release accelerator pedal.
5. Wait 30 seconds.
6. Start car.

Surging should hopefully be gone.
__________________
FBO:JB4, Meth (Dual CM7s), BMS Charge Pipe, NGK 95770 (0.56mm). Dimpled and slotted EBC 3GD discs and yellowstuff pads, Cree LED Angel lights, LED foglights, LED interior lighs, OCC and Braided brake lines. Custom Diff Lockdown Kit, VTT inlets, TMAP sensor. Fuel-it stage 2
12.2179@120.59mph (before inlets,lpfp,diff lockdown,TMAP)
Appreciate 0
      02-09-2016, 09:22 AM   #8
Phil325i
Lieutenant Colonel
Phil325i's Avatar
United Kingdom
59
Rep
1,810
Posts

Drives: E92 325i MSport Coupe
Join Date: Apr 2012
Location: UK South East

iTrader: (0)

Garage List
Thanks for responding. Sadly I've had adaptions re-set and done the throttle re-set procedure. Thanks for the suggestion though...
__________________
E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; BMS clutch stop; BMS CDV; RE g/box mounts; Saikoumichi OCC; K&N; Cyba scoops; BA diff brace; BMW Perf Exhaust; M3 rear spoiler; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 08:08 AM.




e90post
e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST