Independent BMW specialist Surrey/SW London

[KJM]

Morning All,

I have a 2004 645ci that only has 50k mileage on it and is in generally very good condition. (I drove it to Germany last summer without any issues)

Recently though I have been getting a host of error messages flash up (Dynamic Drive fault, power steering etc) When this happens I lose power steering and gearbox becomes very clunky and wont change above 3rd (this happens soon after start-up)

I have had all these errors cleared with a local mechanic but looking for a specialist to diagnose whats causing it and maybe it needs its "brain" replaced as I hear this is a common problem in these older cars where the tech was very new at the time.

Many Thanks

Karl

[Greydog]

Afternoon Karl

Welcome to the Forum

There is a Register of BMW Specialists Google/Siri  will help you should be able to locate one not to far away from you.

Before spending your hard earned here are a few of things to check (1) Check Battery Voltage at the charging points under the Bonnet engine off,  it should be 12.5v anything below that indicates a failing battery which can cause all your issues. (2) Check the Voltage at the Charging Points engine running voltage should be 14.5 + Volts anything lower points to an Alternator/Voltage Regulator issue (3) BMW love multiple earth points the mounting for these can often become corroded check earth continuity or simply undo the mounting bolt clean everything apply electrical contact cleaner and bolt it back

Reset all Fault Codes and check to see if any come back

Dave

[KJM]

Fantastic advice many thanks Dave

I checked the battery yesterday and it was around 11 so definitely an issue there. I have put it on drip charge and will try and get it back up to correct levels. Its a relatively new battery so maybe its just the cold weather - although did drive the car 100 miles to Somerset and back over the weekend so would have thought it would be fully charged. Potentially that suggests an alternator problem?

Thanks again

Karl

[Greydog]

Morning Karl

11v is a dead or dying battery, if you drove to Somerset it should charge the battery OK the issue is the Battery doesn't seem to be holding the charge. My bet would be duff cell in the battery.

The battery inmy E53 4.6is died suddenly 3 years ago the date stamp said it was the original battery (2003) 18 years old The replacement from ECP came with a 5 year warranty but had to be replaced (under Warranty) last year. (Touches wood) the battery in the E70 was replaced 5 years ago and is still going strong. So even though the battery change seems recent it could still die on you

Dave