Motor has noticibly different 'moods'

[LivesNearCostco]

If fuel filter is original at 124K miles, should definitely replace. Don't know enough about fuel pump failures to say if it could get weak intermittently--usually when they fail, they fail to pump any gas and your car stalls or won't start. Could also be VANOS seals but I think that would throw a code most of the time. My VANOS didn't throw codes at 140K miles but then upgrading the seals only delivered a small performance improvement.

And if I'm going 50mph and want some action when flooring the pedal, I'd drop it down to 3rd or 4th gear, not 5th! :-) But you have auto so different final drive ratio so may not be a good analogy.

BTW, since you are auto, I assume it's not a difference in how and when the auto downshifts, or you would have noticed and said something about the downshift, right?

Edit: Yes could be vacuum leak that is not big enough to throw a code and perhaps is inconsistent, maybe related to temperature? Or your car could just have more personality (i.e. possessed like Christine)

[mbeckel]

Has the DME been updated?

Sent from in the bushes

[Hermes]

Has the DME been updated?

Sent from in the bushes

Auto doesn't generally experience the 'dip' as they have different tuning

I'm still betting on vacuum leaks. Seals are only good for so long, and the time has took its toll on even the newest E46. Get the car smoke tested

[mbeckel]

Auto doesn't generally experience the 'dip' as they have different tuning

Ah. Gotcha. Did not know this. Thanks for clarifying

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[KevinC]

Crappy gas?

[danewilson77]

Winter mix of fuel.

"No flamesuit required"

[CarbonZHP]

Stock tuning. Only Chevron 91, best we have. Summer fuel. And yes if I wanted to actually go somewhere going 50 I would downshift. Staying in 5th at 50 just demonstrates when the problem is there, because it seems to effect torque the most.

[ryankokesh]

I don't believe it's a vacuum issue - you'd have codes out the wazoo if it were bad enough to be that noticeable. Fuel pump, from what I know, tends to on these cars at least either work or not work at all. Winter gas sounds plausible, but you're getting the torque momentarily it sounds like. I would imagine, although I don't know for sure, that the degradation in quality would be more minor and consistent.

I would posit that somehow either fuel or air is being intermittently restricted. Either of these situations really should throw some kind of code though. Have you scanned it to see if there are any that haven't thrown a light yet?

If no codes, I would start looking at physical ways the power could be lost. For example, clogged fuel line or some crazy shit like that. But that brings me back to it needing to throw a code because it's running lean.... Weird. I'll keep thinking.


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[ryankokesh]

I re-read the part about the struggling sound. Does anyone think the problem could lie between the engine and the wheels? Funked up transmission or diff or something? Rope got twisted around the wheel? Lol...jk on that last one.


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[ryankokesh]

Have you ever changed your spark plugs?

General question: How do those ignition coil pack things fail?

This is going to drive me nuts...


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