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2003 745Li - Engine Malfunction, Reduced Power fault.

Customer Question
2003 745Li - Engine...

2003 745Li - Engine Malfunction, Reduced Power fault

Mechanic's Assistant: How many miles are on the car? Is it an automatic or a manual transmission?

121,000, automatic

Mechanic's Assistant: Are you fixing your 745li yourself? What have you tried so far?

I have a mechanic but so far no progress as the problem goes away after restarting

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

It only happens when engine is cold....after 10 minutes of driving. Once car is restarted, all is ok

Submitted: 9 months ago.Category: BMW
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Answered in 1 minute by:
10/18/2017
BMW Mechanic: rpmdiag, Tech and Instructor replied 9 months ago
rpmdiag
rpmdiag, Tech and Instructor
Category: BMW
Satisfied Customers: 8,968
Experience: Since 1975
Verified

Hi, I'm Ron and I will be helping you today.
Stand by for a moment while I prepare your answer.

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BMW Mechanic: rpmdiag, Tech and Instructor replied 9 months ago

Reduced power comes from a variety of things, so the tech needs to be watching this with his scan tool exactly when it's happening. That's not easy to do, so the best thing to do is for him to attach a data logger to your computer connector and let you drive the car or just leave it with him. When the problem occurs, the data logger records all that information so the tech can read it back to see what went wrong.

I use this tool all the time for problems like this.

Please understand that I don't know your skill level or tools
you have to assist us. Also understand that I can't see, smell,
hear, or touch the vehicle either, so your patience is
appreciated. JA is a great Q/A site, but it does not replace a
repair shop. So please don’t shoot the messenger if I have to
deliver bad news:)
If you are satisfied with my answer, I would greatly
appreciate a 5 star rating now before you leave the site and I
will still assist you after you have rated me too if another
question pops up. I don’t get credit for helping you until
you rate me

Thanks, Ron

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Customer reply replied 9 months ago
ok
BMW Mechanic: rpmdiag, Tech and Instructor replied 9 months ago

We just crossed each other in the texting,please read the above reply from me.

Thanks, Ron

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BMW Mechanic: rpmdiag, Tech and Instructor replied 9 months ago

Did you have any other questions for me at this time?

Thanks again, Ron

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BMW Mechanic: rpmdiag, Tech and Instructor replied 9 months ago

Thanks again and please remember to rate me 5 stars now
and keep this link in case you need me again later on.
I don’t get credit for assisting you until you rate me
My goal is to assist you in the repair of your vehicle by
supplying you with well educated information. I may not
always have the exact fix you wanted to hear, but my job is
to get you on the right track, which I always do. I can’t hear,
see, smell or touch your vehicle from where I’m at, so your
understanding of that is greatly appreciated. There are no
magical answers, but I do my best to guide you in the right
direction.

Ron

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