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Thread: Confusing 'Running rich' problem...

  1. #1
    Join Date
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    Question Confusing 'Running rich' problem...

    Evening (or afternoon)...! I've got a bit of an odd problem with the 323iC I bought almost 2 weeks ago, and as a previous bmw owner and having owned almost 20 cars in my 10 years of driving, this has me baffled... :|

    The car smells like it's running rich...BUT, there's no drop in power, she's still got lots of torque throughout the rev range, no flat spots and reasonable economy for a 2.5 litre (around 30-35mpg with mixed driving, some motorway, some inner 2-lane carriageways and some screaming around local roads getting to errands).

    The rich running is the only symptom I can give, it runs rich when cold (open loop mode), but then the richness lessens an isn't even apparent when driving, only when at a standstill and even then it's hardly noticeable but it's there...also, there's a rattling/tapping noise when I get on the gas as I'm accelerating...not a loud tapping, and it isn't even audible when the car is sitting stopped at idle. When accelerating hard however, the only way I can describe the noise as the raspy exhaust noise of an E46 M3...

    Any ideas? or am I just being paranoid...? Apart from the above she drives really well with no knocks or bangs, and only the usual slight lifter/tappet noise which I've had on my old M50 and mum has on her M54 (hydraulics right...).

    Thanks!

    - Harry

    - - - Updated - - -

    Guys...? Anyone...? I know it's an odd problem but surely someone must have some input...
    Last edited by silestanix; 06-11-2013 at 07:46 PM.

  2. #2
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    Are u smelling unburnt fuel or raw fuel? How are u calculating mpg?
    duh

  3. #3
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    ^ His mileage will be slightly higher as he's in the UK and their gallon is larger, but even converted, the consumption of 25-30 US mpg is terrific. If you were running rich, you'd know it by your fuel consumption, black exhaust and probably a lack of power if it was really bad.

    If you are really concerned, take it to someone who has the equipment to measure exhaust emissions and/or air fuel ratios and tell you if it's where it's supposed to be. I personally wouldn't be concerned, especially if it's only at idle.

  4. #4
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    Could simply need a new set of spark plugs (make sure you torque them properly). Start there, then see if you can get a set of ignition coils off ebay, here in the US we can get a set of new coils for ~$105.

    Rich running car will eventaully ruin the cats!

  5. #5
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    Quote Originally Posted by 540er View Post
    Are u smelling unburnt fuel or raw fuel? How are u calculating mpg?
    I'm calculating it according to my fill ups mate; I'm smelling unburnt fuel...but only at standstill idle.

    Quote Originally Posted by slocar View Post
    ^ His mileage will be slightly higher as he's in the UK and their gallon is larger, but even converted, the consumption of 25-30 US mpg is terrific. If you were running rich, you'd know it by your fuel consumption, black exhaust and probably a lack of power if it was really bad.

    If you are really concerned, take it to someone who has the equipment to measure exhaust emissions and/or air fuel ratios and tell you if it's where it's supposed to be. I personally wouldn't be concerned, especially if it's only at idle.
    The exhaust isn't that black, if anything normal cars will always have soot on exhaust pipes right...? I've been using Shell V-Power since I bought her 2 weeks ago (99RON Octane Shell fuel with better detergents) so I expected a bit of dirt and soot to come out as the previous owner may have done what 99% of U.K car owners do and run cars on normal 95RON Unleaded. My garage opposite my home does MOT's (U.K Equivalent of your D.O.T tests for emissions)...so I'll go early on Saturday morning and get him to test my E36 out...I'll post up results though. I love your wheels btw mate, could imagine my E36 with a set of those!

    Quote Originally Posted by Eric93se View Post
    Could simply need a new set of spark plugs (make sure you torque them properly). Start there, then see if you can get a set of ignition coils off ebay, here in the US we can get a set of new coils for ~$105.

    Rich running car will eventaully ruin the cats!
    I'll try this avenue in the next week or so (Really busy with work right now ) ..Oh, car has had a new CAT and silencer in the last 5k miles.

    Thanks for your replies gents, much appreciated...!

  6. #6
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    As promised above; I took my car to my friend's garage across the road from me early this morning for a mock M.O.T (or D.O.T for you guys) Emissions Test, he asked me to come early so I wouldn't be disrupting with customers around as his Boss checks the CCTV from time to time and doesn't like me being there (because his daughter ends up talking to me a lot...enough said haha); he stuck the SUN Machine probe into the exhaust and did his emissions testing procedures...She passed... :O

    He said the idle was pretty much perfect on par with what it should be, and at revs it was a tiny bit over bus pass-able, he showed me the machine's screen and told me the lambda on the testing machine has been playing up since Wednesday and a SUN Techie boy is coming out to him on Tuesday to fix the problem and that if the machine was working properly my E36 would have passed without a doubt with absolutely no problem.

    He finished off by saying 'Mate, you have a petrol car now, they always smell different from the Diesels you've mostly had, in my experience your car's running fine so don't worry about it, if you're that concerned just swap out the spark plugs for new ones'.

    Relieved? Oh Yes!
    Last edited by silestanix; 06-15-2013 at 05:36 AM.

  7. #7
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    Hey, so a bit of background, car seems to me like it's running rich but after an M.O.T Emissions test being a Pass, I didn't think much of it; I did however plan to change the spark plugs as a matter of course, and after seeing the recommended BKR6EK plugs at Euro Car Parts with pretty much 40% offI thought it'd be rude not to snap these plugs up at £3 each, costing me £18 for 6. I changed the plugs and fitted the new ones (pretty easy, same as M50). Took the car out and she felt more responsive and had more torque.

    Still smells a bit rich but meh, I'll have codes read next month as I've not much money lol (had to help out my mum).

    Idle's rock solid, pulls hard right up to the red line, quicker now with new plugs, has a sense of urgency about it now, ya know?

    I have pictures of the old plugs, what do you guys think? I've seen a Lot worse, I'm after second opinions.





    #1, #2 and #3




    #4, #5 and #6





    Thanks for your replies...!

  8. #8
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    They were definitely due. But replacing spark plugs will not fix a rich running condition. Find/fix all vacuum leaks, and replace the ignition coils.

  9. #9
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    New coils? really?

    Go to a show that can measure emissions. Could be all in your mind...in your mind....

  10. #10
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    Quote Originally Posted by Eric93se View Post
    They were definitely due. But replacing spark plugs will not fix a rich running condition. Find/fix all vacuum leaks, and replace the ignition coils.
    True...thought it might help a bit though, they needed doing right, lol.

    Quote Originally Posted by truthbtold View Post
    New coils? really?

    Go to a show that can measure emissions. Could be all in your mind...in your mind....
    As above last few posts mate, been to emissions test and she passed...


    ...I feel to just run her now as she is, possibly into the ground and save up in the meantime for my dream car, an Estoril Blue E36 M3; just losing my head with this car lol

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