Close

Results 1 to 22 of 22
  1. #1
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3


    Yes Reputation No

    WTF is wrong with my car?

    I am having the strangest problem w/ my M3. I can't figure out what the deal is.

    My baseline dyno was done in April of 2009. The car had Remus Race mufflers. Everything else was stock. It made 334 rwhp and 250 rwtq on 91 octane gas. Right at the average for a stock 6MT. This was at SP Engineering.

    Around October I re-dynoed at Technik in Long Beach. The car was still the same except I'd switched from stock 18s to 19" Volk G2 rims. My best run on their dynojet was only 317rwhp, and the curve was shot to $#@! past 6000rpm. Right after I was on the dyno I went into limp mode and got a CEL. After waiting a minute and re-starting the car the limp mode was gone. We put a scanner on it right away and there were no active, pending, or stored fault codes. No more limp mode incidents have happened.

    Since October I've done the following mods: Primary cat delete, Macht Schnell filter, Rogue pulley, switched from Remus to RPI axle back, and Powerchip Stage 2 flash.

    I went back to SP Engineering to re-dyno against my baseline of 334. This time I made... 338rwhp and 257rwtq. The curve is strange. From 3000 - 6000 RPM it's gained 10-15rwhp over stock. But as soon as I pass 6000, the curve falls sharply until it's almost exactly lined up with stock. It's like something is holding my car back from making top end power.

    I thought about replacing my fuel pumps, but the parts alone cost nearly $1,000. I don't want to start throwing money, replacing random parts hoping to find the right one. I figure it could be the spark plugs, coil packs, fuel filter, fuel pumps... I am really confused and frustrated by this. The car definitely makes more power in the low and mid range, but at the top end something is holding it back.

  2. #2
    Join Date
    Mar 2010
    Posts
    157
    Rep Points
    88.0
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    can you post all the dyno graphs

  3. #3
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    You know what, I have no idea. Something definitely sounds off and those numbers are pretty low on a dynojet for those mods. I don't get it at all.

  4. #4
    Join Date
    Feb 2010
    Location
    NJ
    Posts
    13,485
    Rep Points
    58.0
    Mentioned
    318 Post(s)
    Rep Power
    0


    Yes Reputation No
    Although a few things could affect the power up top, there is also a possibility that the original dyno is the one that is not correct. A number of things can change between dyno's though. actual weather conditions. fuel used, oil used, oil level, tires used, tire pressure, etc. Much easier to speculate/diagnose with the graph though

  5. #5
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    No, it's more than that. The way the curve drops after 6,000 RPM makes it clear that something is amiss. I found a thread elsewhere about faulty fuel pump controllers that affected some early build M3s (pre May 08), and my car was built in April 08. So I'm looking into that. I have a feeling it's something pretty simple, like a sensor, a coil pack, or a relay. But tracking it down is the problem. I am hoping to find an expert mechanic who can pinpoint it. My method is to just replace everything, but that could cost thousands and I might never hit the right part.

    Anyway, I'll scan my dyno graphs on Monday when I'm back at work and post them up.

  6. #6
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Why don't you have the dealer look into this?

  7. #7
    Join Date
    Jan 2010
    Posts
    927
    Rep Points
    591.0
    Mentioned
    2 Post(s)
    Rep Power
    6


    Yes Reputation No
    Sell the car and buy another used M3. It could be that the "timing" is not properly set(forgot if it's the cams or crank). Maybe a software issue? How many miles on the car when you first got it? Has it been overreved? I kinda doubt that it's the fuel pump though....

  8. #8
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Why doesn't you have the dealer look into this?
    Been hesitant about that because of the mods vs. warranty. Plus the quality of dealer mechanics is pretty much a crapshoot. That being said I got in touch with a master tech who is going to look into it.

    Click here to enlarge Originally Posted by GT3 Click here to enlarge
    Sell the car and buy another used M3. It could be that the "timing" is not properly set(forgot if it's the cams or crank). Maybe a software issue? How many miles on the car when you first got it? Has it been overreved? I kinda doubt that it's the fuel pump though....
    I would take too big a hit selling, plus if I were to sell I'd probably get something else like a Z06. Doubt it's a software issue but anything is possible. It had 30 miles when I first got it. No over revs. We'll see if the tech finds anything. There is a fuel pump controller that is known to occasionally fail.

  9. #9
    Join Date
    Feb 2010
    Posts
    23
    Rep Points
    4.1
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No
    Maybe flash the software back to stock and dyno again. If it's still weak you know it's some sort of mechanical problem.

  10. #10
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Looks like either both of my forward O2 sensors are bad, or my DME is bad... O2s are being replaced, we'll see if this fixes the problem.

    Also found my DME was in PDI mode. Probably been that way since the day I took delivery.

  11. #11
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    1 out of 1 members liked this post. Yes Reputation No
    Replaced O2 sensors and reflashed DME back to the stock using the latest code. My build date was 4/08 so there were a lot of updates. Lost my Powerchip code during the reflash - to be clear, the PC software is not the issue. I was having the power loss and CEL issue when I was still stock. We'll see if the new DME code and sensors fix the problem.

  12. #12
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Click here to enlarge Originally Posted by fstop7 Click here to enlarge
    Replaced O2 sensors and reflashed DME back to the stock using the latest code. My build date was 4/08 so there were a lot of updates. Lost my Powerchip code during the reflash - to be clear, the PC software is not the issue. I was having the power loss and CEL issue when I was still stock. We'll see if the new DME code and sensors fix the problem.
    Keep us updated.

    Hopefully replacing the 02 sensors will help but you also mentioned you might replace the DME itself?

  13. #13
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Keep us updated.

    Hopefully replacing the 02 sensors will help but you also mentioned you might replace the DME itself?
    The DME was OK so all that was needed was to bump it up (along with all the other modules) to the latest revs. There were 26 modules flashed. Everything from DME, EDC, and DSC to the stereo.

    The stored fault code that kept showing up in ISIS was 2743 - Oxygen sensor heater diagnosis before cat, bank 2. The code persisted after the sensor was replaced, but went away after the DME updates. Hopefully that was the cause.

    Also, for some reason, the car had been left in PDI mode. The tech had no idea why that would be or if it hurt performance, usually PDI mode is turned off before the customer takes delivery. The original dealership probably forgot to change the setting all the way back when I bought the car.

    Something else interesting - the "State Inspection" category under "Service" in iDrive had gone missing a while back, I didn't even notice it was gone until it re-appeared after the DME updates. Seems like a typical BMW electronics bug.

  14. #14
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Click here to enlarge Originally Posted by fstop7 Click here to enlarge
    The DME was OK so all that was needed was to bump it up (along with all the other modules) to the latest revs. There were 26 modules flashed. Everything from DME, EDC, and DSC to the stereo.

    The stored fault code that kept showing up in ISIS was 2743 - Oxygen sensor heater diagnosis before cat, bank 2. The code persisted after the sensor was replaced, but went away after the DME updates. Hopefully that was the cause.

    Also, for some reason, the car had been left in PDI mode. The tech had no idea why that would be or if it hurt performance, usually PDI mode is turned off before the customer takes delivery. The original dealership probably forgot to change the setting all the way back when I bought the car.

    Something else interesting - the "State Inspection" category under "Service" in iDrive had gone missing a while back, I didn't even notice it was gone until it re-appeared after the DME updates. Seems like a typical BMW electronics bug.
    So does the car feel any different or better? Are you going to flash it again?

  15. #15
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    So does the car feel any different or better? Are you going to flash it again?
    Didn't get a chance to wind it out yet. I will probably dyno, see if things look better, then re-flash and re-dyno.

  16. #16
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Click here to enlarge Originally Posted by fstop7 Click here to enlarge
    Didn't get a chance to wind it out yet. I will probably dyno, see if things look better, then re-flash and re-dyno.
    Smart way to do it.

    Hope everything is fixed and I look forward to seeing the results.

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  17. #17
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Update?

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  18. #18
    Join Date
    Mar 2010
    Location
    Kingdom of Bahrain
    Posts
    2,707
    Rep Points
    2,103.5
    Mentioned
    27 Post(s)
    Rep Power
    22


    Yes Reputation No
    Updates?
    Click here to enlarge



    EURO 04 M3 Current Mods:GC DAs, Eibach Sways, PF RTAB's, RE RCAs, INTRAVEE II, Black Roundels, ///MFEST Badges, Depo's, Screen protector for NAV display, VCSL Bumper + Race Lip & CF Trunk & CF Rear Diffusor, DIETZ TV in Motion, SS= V1 Headers + catless pipes + X-Pipe + SS Sport Exhaust, Z8 Starter Button, Lamin-X, OEM CSL interior, OEM CSL Steering, OEM CSL Intake, OEM CSL Roof, MSS54HP + OEM CSL Tune, BBS CH's, LIGHTWERKZ, 355mm ST40 BBK, BW Oil Cooler....

  19. #19
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Nada, been busy. Not reflashed yet, just running w/ CEL.

    Saw some posts on the other forum about detonation and bad bearings, but I don't hear anything that sounds like valves clattering and oil consumption is normal. I still might pull the spark plugs sometime just to take a look at them, see if there's any oil on them and what the gaps are like.

  20. #20
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    I should post the final update on this. Ever since I got the latest OEM DME updates my car has run much better.

  21. #21
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    118,800
    Rep Points
    31,797.3
    Mentioned
    2084 Post(s)
    Rep Power
    318


    Yes Reputation No
    Click here to enlarge Originally Posted by fstop7 Click here to enlarge
    I should post the final update on this. Ever since I got the latest OEM DME updates my car has run much better.
    But with the OEM software?

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  22. #22
    Join Date
    Nov 2009
    Location
    la la land
    Posts
    303
    Rep Points
    256.1
    Mentioned
    0 Post(s)
    Rep Power
    3



    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    But with the OEM software?
    Yep. I think the older OEM software was more aggressive about pulling timing. Just my suspicion.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •