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Steve
Steve, BMW Expert
Category: BMW
Satisfied Customers: 23216
Experience:  BMW Expert
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Ive had my 2008 125i SE coupe for three years and right from

Resolved Question:

I've had my 2008 125i SE coupe for three years and right from the start I noticed that from time to time it hesitates momentarily when I accelerate hard in a higher gear (usually 4th). Initially, I found that this tendency seemed to disappear after a long motorway journey or just by driving the car hard for a while. However, I'm not so sure now that this necessarily does the trick. Is this a fairly common known fault on this model, or have I just been unlucky? If not, in what areas would you want to look when diagnosing the problem?
Submitted: 2 years ago.
Category: BMW
Expert:  Steve replied 2 years ago.
what is the last 7 digits of the vin of the vehicle?
Customer: replied 2 years ago.

The last 7 digits are: VH95049.

Expert:  Steve replied 2 years ago.

is the problem with the transmission, or with the engine hesitating?

 

Customer: replied 2 years ago.

No, the transmission's manual - it's definitely the engine that's hesitating.

Expert:  Steve replied 2 years ago.

I will provide an honest answer and am doing so in good faith. I trust this will be appreciated. Please remember that a low rating PUNISHES me for being honest and that I receive nothing for my time until a positive rating is clicked.

this would suggest possibly a faulty temp sensor, or something else in the drive-by-wire system (pedal, .computer, throttle)

 

for this type of issue, if no warning light comes on, with only a mild symptom, you will likely need to have real time diagnostics carried out while the issue is presenting itself, using a scan tool which can monitor all inputs and outputs from the engine control system in real time, in order to attempt to identify what may be out of spec

 

Sorry if you were hoping for a different answer, please don't shoot the messenger - I can only give the honest answer, which I have. Please remember that a low rating PUNISHES me for my honest and prompt response, and I receive nothing for my time and answer until a positive rating is clicked.

Please let me know if you have further questions. Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you. Best wishes with your vehicle

Customer: replied 2 years ago.

Thanks for the prognosis, Steve. What does the temperature sensor measure the temperature of exactly, and what does the computer tell the car to do when it detects a temperature that's too high or too low? Also, you talk about "something else in the drive-by-wire system". Could that be some other sensor in that system?

Expert:  Steve replied 2 years ago.

Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you.

 

the temperature sensor measure the temperature of the transmission oil

 

if it is faulty it can cause poor shifting behavior

 

I have listed the major components of the drive by wire system - pedal, computer, throttle

 

there isn't anything else in that system that would likely cause what you are experiencing

 

again, you will need a real time diagnostic if you hope to avoid guess work

 

Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you.

Customer: replied 2 years ago.

What I was really trying to say was: Do the pedal and throttle components have their own sensors? Does "drive-by-wire" actually necessitate having sensors all over the place?

Expert:  Steve replied 2 years ago.

Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you.

 

the pedal and throttle are each a single component, there are no sensors you can replace on either of them, and there are no other sensors elsewhere. Please kindly select a positive rating, thank you

 

 

Please do not forget to click a positive rating as this is the only way I receive credit for my answer, thank you.
Steve, BMW Expert
Category: BMW
Satisfied Customers: 23216
Experience: BMW Expert
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