Engine To chassis ground alternative

[angus337]

Hi folks.

After replacing the main live cable to the starter, 100A fuse and alternator, due to the state of the connections, I decide to replace the main engine to chassis ground aswell, assuming this could be in a similar state.

However, I realised as I was about to remove the old one the that existing ground Is connected to one of the the engine mount bolts. I don't really want to remove this, in case I can't get it back in easily. Is there an alternative grounding point in the the chassis that would be suitable.

Also wanted to check what the sensor is next to the engine earth, below the alternator.

Cheers, nick

[Belle427]

You could drill and tap your own in the chassis.
The engine mount isn't ideal, when I replaced my starter cable I added a short 50 mm cable from the battery to the engine.
There was a spare bolt in the rear of the block on the passenger side, a bit awkward to get at but manageable.
I chose to do this as I didn't fancy pulling carpets out to find the main chassis ground.

[mk1fan]

The 350i has the battery earth connected to the engine block.

I also added a new one fro the block to the chassis when I renewed them.

[Steve_D]

Start undoing the earth bolt on the engine. once released if you can undo the remaining thread by hand you will have no problem refitting the bolt. If it remains difficult to turn then you have proved your fears and can tighten it again and go for plan B.

Steve

[Sardonicus]

Just retain that current ground point and add another from gearbox to chassis lots of mounting points near the tail-housing your starter etc will still benefit from the extra return

[Hedgehopper]

I left my existing earth lead connected as before and ran a new 40mm lead from the same chassis earth direct to the lower starter motor fixing bolt.

[Sardonicus]

Hedgehopper said:

I left my existing earth lead connected as before and ran a new 40mm lead from the same chassis earth direct to the lower starter motor fixing bolt.

Its also very easy to come off the batt ground - terminal through the foot kick-well (behind battery box) via a grommet and straight onto the engine block (tapped hole available) and yes I have done this too the only problem I have with this is ....... I should have done it sooner

Edited by Sardonicus on Tuesday 22 August 12:05

[angus337]

Thanks for the help guys.

Engine mount bolt wasn't coming out easiliy, so installed an additional ground to the lower starter motor bolt.

I have already installed a 25mm2 ground cable from the back of the engine block to the footwell to connect my additional grounds for the megasquirt coilpack driver, wideband controller and coilpack relay. To ensure they are grounded to the same point as the ECU. I guess could also connect this to the battery ground to give me another earthing point.