Hello everyone - I’m new to this forum.

I have a year 2000 E46 323ci that has an engine that is running really erratically and unpredictably. The car is hardly used, it passed its MOT in February this year but the running poor issue has been evident for over a year. The issue: sometimes the engine will start fine - no warning lights - smooth and lovely as it should be - drive it for 30 mins or so in local city traffic and without warning the engine starts to run really lumpy - all the warning lights come on and the car will hardly pull more than 10mph - pull off the road - turn the ignition off - wait - start again with the same problem - do this a few more times - then the lights go off and the engine runs fine again - for 30 mins or so. This can also happen in reverse - the car will be running smoothly - park at home - start the following day and it’s straight back to lumpy running with all the warning lights.

I have had the throttle body replaced, twice, the ECU cloned and replaced, a new air input ducting - all carried out by a BMW specialist but the problem continues. the specialist is unfortunately now not answering calls.

I’m not a mechanic and I’m fumbling around in the dark here - when it’s running well it’s a lovely car - when it’s bad it’s really undrivable.

my next thoughts are the vanos unit and/or solenoid valves - or as the car is worth so little - scrap it!

can anyone on this forum suggest anything - I don’t have access to code reading software - it would be great to speak to an enthusiast who might have some ideas - it can’t be a massive problem to solve as it can run really well - but just occasionally!

any help or advice would be greatly appreciated - or if there is someone in SW London who might want to have a look that would be fab - thanks in advance.

Roger M

Morning Roger

Welcome to the Forum

As the issue is erratic I would suspect either coil packs or plugs if there are no Vacuum leaks, as the car is used little I would start with a can of good Electrical Contact cleaner and make sure all sensor plugs are good and clean, then all coil pack connections. Check all the Vacuum lines for signs of cracking or splits those are the simple practical things but Diagnostics are the way to go.

I wonder if there is a member on here who is close to you?

Dave