High RPM up-shift

Tiny
BGEB2017
  • MEMBER
  • 2005 BMW 330
  • 3.0L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 105,000 MILES
Hello, Sorry long post. I am experiencing late shifts (ie, high rpm shifts) with my transmission. The vehicle is listed above it is the XI model with the GM A5S390R aka 5L40E steptronic transmission. I first noticed the issue driving through a park (fifteen mph speed limit), the car would not up shift unless I gave it more gas. Since, it has been happening specially after long drives with the AC on. There is a noticeable whine in low gear. Took it to two transmission places and they said transmission is fine. As of late I have noticed that if I press the throttle pedal lightly the car vibrates for a split second as the car starts to move and also I have to press the gas pedal further for the car to move faster, as if there is no low-end torque. The car shifts smoothly up and down when it does. Fast acceleration is smooth and precise. Leisure drives are not possible. One day after about two hours of highway driving, I got off the highway and the engine sounded louder than usual and there was a noticeable pop pop pop exhaust sound as I waited for a light to turn green, perfect idle! No MIL, engine or transmission codes. I know it is a lot but I would be grateful for your expert advise.
Saturday, August 19th, 2017 AT 11:35 AM

14 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Hello,

this sounds like a classic plugged catalytic converter. What happens is as the cat starts to plug it drives the vacuum down in the engine which the computer sees as under load so it backs up the shift points.

Run this test.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please let us know what happens.

Cheers, Ken
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Sunday, August 20th, 2017 AT 11:59 AM
Tiny
BGEB2017
  • MEMBER
  • 8 POSTS
Thank you Ken. Appreciate the feed back. The problem does not seem as bad as needing a new transmission which is what I thought was the issue. The problem has been driving me up a wall, I even bought a BMW specific scanner to try and figure it out. There are no codes! I will have it checked out and revert back. Thanks again.
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Monday, August 21st, 2017 AT 6:58 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Please let us know what happens so it will help others.

Cheers, Ken
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Monday, August 21st, 2017 AT 11:40 AM
Tiny
BGEB2017
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I will as soon as I can get it in to have it look at. Thanks again.
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Wednesday, August 23rd, 2017 AT 5:43 AM
Tiny
BGEB2017
  • MEMBER
  • 8 POSTS
Hello, had the car checked out. Nothing wrong with the exhaust yet (105K miles). They did however find a bad water pump (lots of play in the shaft and noisy bearing (not even 15k miles on this metal impeller unit, garbage), a bad thermostat (no codes just running between 87-92C), and also fouled up plugs. Marginal improvement after repairs.

Is there anything else that could be causing my symptoms? I read somewhere that bad O2 sensors can be a cause but then again I also read VANOS seals, TPS, Camshaft sensor, MAF can cause bad performance? Again no codes so I'm at a loss. Before repairs got some live data for O2 sensor, pre cat.15-.75mv, post cat steady.70mv when hot, how do these reading look?

Again no codes. Thanks very much for your assistance and please let me know what else I should look into.
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Thursday, August 24th, 2017 AT 6:42 AM
Tiny
KEN L
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  • 54,137 POSTS
I would think the MAF sensor is your best bet for low performance and no codes, the rest would trigger a code.

Here is a guide to help you see what you are in for when replaceing the MAF sensor,

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Please let us know what happens.

Cheers, Ken
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Thursday, August 24th, 2017 AT 10:31 AM
Tiny
BGEB2017
  • MEMBER
  • 8 POSTS
Thanks again Ken. I know, the thermostat and plugs were bad and never triggered misfires or low temp codes either. Pump issues would not through codes until catastrophe strike. Would it be possible the engine needs a bit of time to adapt to the new parts? It sure does sound much more crisper now.
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Thursday, August 24th, 2017 AT 10:45 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Not really it should respond instantly, How did you make out with the MAF? Here is a diagram to help us along.

Please let us know what you find.

Cheers, Ken
Image (Click to make bigger)
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Friday, August 25th, 2017 AT 11:53 AM
Tiny
BGEB2017
  • MEMBER
  • 8 POSTS
Hi, thanks for the links/pics, I cleaned the MAF with recommended cleaner and reset engine adaptation. It is a bit better still. I ordered fuel filter and oxygen sensors, mine are original and mpg has been falling steadily (21-17 mpg). Also, even though the cats were found to be working, I still think your point about them being clogged is cause for concern, maybe the shop I took it to didn't find a Catalyst System Efficiency below threshold code and took that as them being ok. Why isn't this code showing if the cat(s) are bad?

Anyway maybe new sensors (they were due for replacement at 100K) will provide some new clues. No codes, everything is fine, except it isn't. Thanks
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Friday, August 25th, 2017 AT 1:40 PM
Tiny
KEN L
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  • 54,137 POSTS
I would check those cats :)
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Friday, August 25th, 2017 AT 7:18 PM
Tiny
BGEB2017
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  • 8 POSTS
Hello, just wanted to update. Had BMW dealer diagnose the problem and they came up empty. The issue still persists and maybe getting worse. Thanks for your help.
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Saturday, October 21st, 2017 AT 2:15 PM
Tiny
KEN L
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Sometimes cleaning the MAF won't work and you must replace it. It is a good idea to do anyway with that kind of mileage.
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Sunday, October 22nd, 2017 AT 5:48 PM
Tiny
BGEB2017
  • MEMBER
  • 8 POSTS
Hi, I know it's hard to do this over the internet so thanks for trying. If the computer is not complaining then everything must be fine, those are the words of a "Master" BMW mechanic! Must mechanics can read and pass a Master's test but when it come to diagnostics it is hard to find one who can find their way around a car without a computer. Sorry venting a bit here. I will try to find a working used MAF and give that a try. It may take me a while but I'll report back. Thanks again.
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Tuesday, October 24th, 2017 AT 1:00 PM
Tiny
KEN L
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Please let us know what happens. No problem on the vent, its a tough job and most don't know how to do it very well.
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Wednesday, October 25th, 2017 AT 2:25 PM

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