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2003 E46 320i, Opinions Please(Cold start misfire)

13K views 79 replies 8 participants last post by  hontoir 
#1 · (Edited)
Well as stated in my other thread I am getting pi**ed off at my emissions deterioration light returning in-frequently, and rather than taking the car back in for its THIRD diagnostic session I figured it might be easier to buy something.

From reading threads people have had success running INPA on a laptop and using a USB to OBD2 lead.

Is this the sort of thing I should be looking at? Clicky

I don't fancy messing around with shorting pins on a vag com lead so will this work?

Thanks
 
#60 ·
im perplexed i know these cars sometimes can run lumpy from cold by definition mine does now and again and me mates but they never throw a code tho...

ive read somewhere that an iffy CCV can cause missfire too...


the missfire time and length and when to me sez its only doin it while its running open loop myself which makes me suspicious i just cant see it being a HVA but ya never know with these feckin things...
 
#62 ·
i wouldnt pay a lot of attention to it just being 1 cylinder i came a cropper on that one with me lean running fault it said only on bank 1 but it turned out to be the lower intake hose that feeds both banks i was eyeballing the bank 1 02 sensors up cos of it and sent me in the wrong direction briefly..


fickle and twitchy things diags are at the best of times...
 
#63 ·
I am definitely not ruling it out, however, it is more probable to be something that can only affect the one cylinder.

I might get a screwdriver out and see if I can establish where this ticking is coming from in the morning.
 
#69 ·
This is what the indy has said:

Hi Mike,

Wont be cheap I’m afraid as the vanos has to come off to get the cams out to access the lifter. The Autodata standard repair times are quoting around 5.3 hrs (£258.75 labour) but does not include time to reset the cam timing or any parts that may be required (lifters, cam cover & vanos gaskets etc).

Personally I would scope the injector & coil signals first – it’s cheaper & rules them out before major-stripping the engine apart! I would check those for a couple of hours labour, so £90 (may be less if it takes less time). However, as the car only does this when cold I may have to have the car for a couple of days to scope it when the fault actually occurs.
Followed by

I just double-checked & checking/resetting the cam timing alone is listed as 4.2hrs so I guess they have included that in the 5.3 as most of the works for both jobs are the same as far as I can see!
So basically it is either a transistor in the ecu that is sending an incorrect signal to either coil or injector.

Or it is one of/all the lifters on cylinder 5..

Or neither..
 
#78 ·
Sorry guys, another update.

Car went in yesterday (Thurs), has the latest ECU update installed. Scoping was conducted on the coil/injector in question, all readings were good.

Indy contacted two BMW specialists and they all agreed that it is a hydraulic lifter problem with cylinder 5, which is sort of what I suspected.

Downside is that to replace all 24 it is getting on for £900.. Upside is that there is a product called Forte Top End Treatment, which I will be giving a go next week.
 
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