Intermittent Speedo

Post Thu Nov 09, 2006 6:37 pm

My 325 has developed a curious fault.

The speedo started cutting out. At first I thought it was an intermittent fault, probably just down to a loose connection. Then I noticed that it cuts out everytime touch the accelerator. It comes back a fraction of a second after lifting off.

Any ideas anyone???????????

Post Thu Nov 09, 2006 7:19 pm

I think I just found the problem. Went to check the speed sensor connector on the diff and the cables snap off. Corroded to buggery!

Post Thu Nov 09, 2006 10:04 pm

Very common. The copper in the cable "work hardens" due to vibration and becomes stiff and brittle.
Replace the plug and 300mm of wire or so with a similar yellow headlamp connector of a scrapper.

Post Fri Nov 10, 2006 8:06 am

Thanks for that! I've been scratching my head looking for a replacement connector. I guess a good helping of silicone sealant would be a good idea to stop water ingress.

Post Fri Nov 10, 2006 8:58 am

No silicon sealant required. You own a BMW, not a Ford!
Standard silicon sealant should never be used where the sealant can contact the metal of the connectors in a plug and socket, as it produces acetic acid as it cures, which will promote corrosion.
Silicon grease, however, is a completely different thing. Plenty of this should be used in every plug and socket on the car.

Post Fri Nov 10, 2006 5:58 pm

Thanks for the advice. Silicone grease it is!