Subject: Re: New Vanos rings- increased fuel consumption? Author: rajaieq as Rajaie (moderator) : 955 posts Posted on: 2010-01-26 16:55:10

I have an OBDII code reader, Autoenginuity, that can read fuel adjustment values. I have noticed from reading multiple cars that a good LTFT adjustment percentage is less that +/- 3%. The best value would be zero and I have seen this on some cars. A positive number indicates an increase in fuel spray and a negative number is an indication of a decrease in fuel spray. A positive number indicates the DME is increasing the fuel as a response of excessive oxygen noted by the pre-cat O2 sensors.
From my experience a positive value greater than 3% is a sure indication of a problem. This is often a vacuum leak. The value can be as high as 10% and this usually causes notable performance symptoms.

I wonder if your large LTFT adjustments values, the engine pinging, and the oil burning are all related. The new vanos seals might have exacerbated this problem and caused the increased fuel consumption.
If the engine is burning oil it's also likely importing not just oil but also air into the cylinder. The oil and extra air in the cylinder could cause the pinging. At 8% fuel adjustment you might be running lean enough to cause pinging.

Rajaie
528i 5sp 06/00

• New Vanos rings- increased fuel consumption? - webhorn4477 2010-01-24 18:39:24 (1137 views)
  • Re: New Vanos rings- increased fuel consumption? - Rajaie 2010-01-24 22:00:24 (627 views)
    • Re: New Vanos rings- increased fuel consumption? - webhorn4477 2010-01-25 08:20:37 (685 views)
      • Re: New Vanos rings- increased fuel consumption? - Rajaie 2010-01-26 16:55:10 (580 views)
        • Re: New Vanos rings- increased fuel consumption? - webhorn4477 2010-01-27 08:55:18 (622 views)
          • Re: New Vanos rings- increased fuel consumption? - Rajaie 2010-01-27 16:22:50 (429 views)
            • Re: New Vanos rings- increased fuel consumption? - webhorn4477 2010-01-27 19:52:45 (424 views)
              • Re: New Vanos rings- increased fuel consumption? - koveras 2010-03-17 12:55:32 (416 views)
                • Yes, i did. See... - webhorn4477 2010-03-17 18:11:01 (393 views)
              • Ok. Let us know how things go (nt) - Rajaie 2010-01-28 20:16:58 (454 views)
  • Re: New Vanos rings- increased fuel consumption? - poolman 2010-01-24 19:06:05 (521 views)
    • reply@poolman - webhorn4477 2010-01-24 19:34:16 (461 views)
      • Re: reply@poolman - poolman 2010-01-24 20:26:06 (427 views)
        • Re: reply@poolman - webhorn4477 2010-01-24 20:43:17 (785 views)
          • Re: reply@poolman - Rajaie 2010-01-24 21:54:39 (457 views)
            • Re: reply@poolman - webhorn4477 2010-01-25 07:11:21 (461 views)
              • Re: reply@poolman - poolman 2010-01-26 19:36:01 (393 views)
                • Technically not... (pic) - ZetaTre 2010-01-27 17:26:42 (472 views)
                  • Great shot - poolman 2010-01-27 22:02:54 (410 views)
                    • Yea, but that's with the head off... - ZetaTre 2010-01-28 16:34:50 (379 views)
              • Re: reply@poolman (pic) - ZetaTre 2010-01-26 17:18:06 (458 views)
              • Thanks for the super info! (nt) - Rajaie 2010-01-26 15:41:51 (423 views)
              • Re: reply@poolman - poolman 2010-01-25 08:01:51 (396 views)