BMW 335i electrical issues

[Dylan7878]

Problems with car 

 

just purchased a 2007 335i unknowing it had issues 😡any advice on what they could be

(Idles fine and drives fine if not driven hard) 

1. Engine power reduced sign (limpmode) comes on after hard acceleration it clears if turn off/on car, car also feels bogged down sometimes

 

2.abs light, traction light both yellow come on randomly and stay on still until turn car off/on then might clear might not 

 

3. When you click the start button it sounds like a relay latches under Bonnet but nothing after and car does not start, if bump started car runs fine 

(Has had new battery)

 

[Greydog]

Morning Dylan

Welcome to the Forum

First did you buy from a Dealer/Garage if so start there if you brought private you may well be on your own.

With luck you got it cheap so repairs won't make it uneconomical.

First place to start is are you able to DIY or will you be relying on a garage? If in the hands of a Garage factor in labour rates and time off the road. A BMW Specialist will generally be between 1/3rd to 1/2 of a BMW Dealer labour cost, a good Independent Garage around 1/3rd.

Next the battery when was it fitted? is it correct for the car?, was it NEW or was it "another" battery?

To begin the battery needs testing it should show 12.8v at the charging points under the bonnet engine off anything below indicates a discharged/dying battery. With the engine running you should see 14.5/14.8v tested at the same place which would indicate the charging system is OK. 

The faults you mention could be sensor issues caused by low voltages or failing sensors a Diagnostic session with a BMW capable code reader would give a better indication and faster diagnosis.

Fault 1. Limp Mode could be Throttle body or throttle position sensor or cam position sensor either Diagnostics or test sequence needed. Replace if required 

Fault 2. Again a sensor issue at one of the wheels or an ABS pump fault test if capable or Diagnostics sensors can be changed the pump (if it is at fault) can be repaired at a reasonable cost.

The click you hear could be the starter relay or the solenoid either sticking or just not functioning due to low voltages? Fully charge the battery (use the under bonnet charge points) When fully charged leave the car shut up after 15min the light by the gear lever should go out if it doesn't something is not letting the car shut down check any aftermarket additions (Radio.Bluetooth, Camera etc) After a few hours measure the voltage under the bonnet if it has dropped and the car is asleep suspect the battery

Dave