Warm up running issues

Buck1961

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Jun 17, 2025
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3
Hi all, new to this forum. I have a 1998 Z3 M Roadster in lost mint condition with very minimal nicks or imperfections. Love the car it’s so fun to drive. I am having an issue though where the car runs great for about 10-14 miles and once heated up it looses power, almost as it is a catalytic and has somewhat of a fluttery sound to it. Once it cools off, it’s back to running normal. The check engine light does pop on when this happens but goes back off when cooled down. Any insight would be helpful. Thanks!
 

ChrisD

Zorg Addict
Joined
Nov 29, 2023
Points
54
Location
Evesham
Model of Z
M44
Your engine control module will have stored a code for the CEL event that will provide information on what the trouble may be. A code reader will help with the diagnosis of your problem. Knowing what code is stored should help eliminate random guesswork on your issue.
 

Buck1961

Newbie
Joined
Jun 17, 2025
Points
3
Your engine control module will have stored a code for the CEL event that will provide information on what the trouble may be. A code reader will help with the diagnosis of your problem. Knowing what code is stored should help eliminate random guesswork on your issue.
Chris, quick question, if you know. I just purchased the Schwarzenegger BMW/MINI Scanner 14020SCH for my car, says it’s compatible however the first time I hooked it up it couldn’t auto scan the VIN so I had to manual input. It picked it up and identified the car but instantly gave an error count not read the car or VIN or something like that. So seems I have to do a little more reading and research. Anyway, the question is what type of scanner do you use or suggest?
 

Oddly Godly

Zorg Guru (III)
Supporter
British Zeds
Joined
May 17, 2019
Points
135
Location
dunstable
Model of Z
z3 2.8
On most z3s you need to connect the scanner to the pac man socket in the engine bay. You can get an adapter cable for it. If you connect to the inside socket in the footwell you get limited results.
 

ktnez99

Zorg Guru (IV)
British Zeds
Joined
May 18, 2018
Points
164
Location
West Midlands
Model of Z
Z3 2.8L
Very interesting. I have a NT150 scanner which I have found very difficult to use. Any advice on how to use this would be much appreciated, please.
 

Buck1961

Newbie
Joined
Jun 17, 2025
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3
Chris, quick question, if you know. I just purchased the Schwarzenegger BMW/MINI Scanner 14020SCH for my car, says it’s compatible however the first time I hooked it up it couldn’t auto scan the VIN so I had to manual input. It picked it up and identified the car but instantly gave an error count not read the car or VIN or something like that. So seems I have to do a little more reading and research. Anyway, the question is what type of scanner do you use or suggest?
On most z3s you need to connect the scanner to the pac man socket in the engine bay. You can get an adapter cable for it. If you connect to the inside socket in the footwell you get limited results.
Good to know, I did saw the option and wasn't certain if it applied to mine or not. Thanks I will look into this. Sorry about the "Schwarzenegger" I need to turn off my spell correct I guess. I'm sure there is no such scanner out there with that name! LOL

Thanks again and I will share what I come up with when I get the correct cable. I am in the process of changing brakes and rotors all around so the scanner will be the next thing to do.
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Since yours is a 1998 model it may be one that has OBD1 and that can be problematic using scanners on it. Cars with OBD1 do require BMW software running on a laptop with a dedicated serial cable not a usb type. BMW INPA is the software thats needed on the laptop. I did manage to scan a 1998 car using my Launch tablet scanner using the 20pin to 16pin cable changer on the engine bay Pac-man socket but those tablet type scanners cost around £300 so an expensive investment. The popular Creator 310 obd scanner couldn't communicate with the 98 car.
 

Buck1961

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Joined
Jun 17, 2025
Points
3
Since yours is a 1998 model it may be one that has OBD1 and that can be problematic using scanners on it. Cars with OBD1 do require BMW software running on a laptop with a dedicated serial cable not a usb type. BMW INPA is the software thats needed on the laptop. I did manage to scan a 1998 car using my Launch tablet scanner using the 20pin to 16pin cable changer on the engine bay Pac-man socket but those tablet type scanners cost around £300 so an expensive investment. The popular Creator 310 obd scanner couldn't communicate with the 98 car.
Thank you for the feedback, I'll look into this as an option in case I have no choice. Good information thank you.
 

Buck1961

Newbie
Joined
Jun 17, 2025
Points
3
Chris, quick question, if you know. I just purchased the Schwarzenegger BMW/MINI Scanner 14020SCH for my car, says it’s compatible however the first time I hooked it up it couldn’t auto scan the VIN so I had to manual input. It picked it up and identified the car but instantly gave an error count not read the car or VIN or something like that. So seems I have to do a little more reading and research. Anyway, the question is what type of scanner do you use or suggest?
So I did a little more investigating and got the scanner to work. It is showing a “motor electronics DME Fault1”. Diagnostics trouble code ID P0335. The description was a Crankshaft position sensor ‘A’ circuit. Does not seem to be an expensive or difficult fix. The more I looked into this, the sensor reads a toothed wheel on the crankshaft which determines the position of the crankshaft during running, in short explanation. This kind of makes sense in that the motor developed a quick skip and looses some power when it warms up, after driving a few miles. It runs normal when it cools down and starts back up after warming up again. So, I’m thinking it may be a sensor starting to fail. Anyone who has experienced this or knows more about it, please let me know. I may just go ahead and replace the sensor for $150 and see if this clears it up.
 
Last edited:

Duncodin

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Sep 8, 2021
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159
Location
Pontrhydyrun - in Crow Valley
Model of Z
M44 FrankenZed
I have a March 1999 car. Pre face.lift.

Under dash there's a little plastic lid where I imagine later cars have their ODB connector. But there's nothing there on my car.

I have the creator 310 and that works fine connected to the socket in the engine bay.
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Could well be the sensor failing when hot, usual for the camshaft sensors to go bad inlet or exhaust but since you have a code for the crank sensor go for that. Had a look at Realoem parts site for the Z3M but couldn't see the crank sensor listed, go to Real oem site and search for your car using the last seven letters and numbers of your Vin number to bring back listing for all parts fitted to your car. Link here https://www.realoem.com/bmw/en/select
 

Buck1961

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Joined
Jun 17, 2025
Points
3
Could well be the sensor failing when hot, usual for the camshaft sensors to go bad inlet or exhaust but since you have a code for the crank sensor go for that. Had a look at Realoem parts site for the Z3M but couldn't see the crank sensor listed, go to Real oem site and search for your car using the last seven letters and numbers of your Vin number to bring back listing for all parts fitted to your car. Link here https://www.realoem.com/bmw/en/select
Great thanks for the link I'll check it out. it was definitely the crank and not cam, I was thinking the same thing as you but the description of the purpose the sensor serves seems to align with my problem. Worse case is that I will be out a few bucks and rule that cause out and move on to the next.
 
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