Focus st 225 vibration problems

[Jake L]

Hi, has anybody had any issues with vibrations when accelerating at low revs? Mainly 2nd, 3rd and 4th gears, but once I’m above 2500rpm the vibrations stop. Wheels and tyres are all fine and drive shafts look in good condition. Any help would be appreciated 

[theelectricianjoe]

Ground negative cable bolted to vehicles frame done ***** poorly at the factory build. Unbolt from frame, thoroughly clean/scrap/remove all paint completely till you see shiny metal surface, but only for surface area that will be directly mated beneath and around the negative cable that will be reconnected to this point. FYI: best results is to apply dielectric grease to the now unpainted surface for grounding as well as a little to end terminal of negative cable before reattaching. Issue at fault is motors inside transmission as well as other  electrically dependent items are not getting adequate supply causing erratic or low functioning operations.

[Guy Heaton]

That's a really good tip, I'd never have imagined that.

[mjt]

11 hours ago, theelectricianjoe said:

Ground negative cable bolted to vehicles frame done ***** poorly at the factory build

I can vouch for that. When I changed the battery on our Mk3 I disconnected the ground cable at the suspension tower and found the surface under the terminal completely painted. It seems it's been relying on making contact through the bolt threads and the flange of the bolt. I cleaned the paint off under the terminal and as I didn't have any dielectric grease I used some copper grease.