Rusty grounding points

[AFlex]

Was doing some DIY a few weeks ago and noticed one of my grounding points is seriously rusty.

Anyone know how to clean these up? How do you do it? Looks like it is a difficult part to completely replace - can't see where the other side goes.

(it's around the middle left of the photo below)

[GS300h2014]

They look pretty hefty cables, do they connect to the starter motor or the Battery? I wonder if the joint's function is a cable connector rather than an earthing point. Is this a 'if it ain't broke don't fix it situation'? Have you any problems or symptoms with your car? 

[AFlex]

37 minutes ago, GS300h2014 said:

They look pretty hefty cables, do they connect to the starter motor or the battery? I wonder if the joint's function is a cable connector rather than an earthing point. Is this a 'if it ain't broke don't fix it situation'? Have you any problems or symptoms with your car? 

Totally get what you mean about 'not broke so don't fix it'

However I have had some odd things happening with regards to fuel sometimes cutting out when going over large bumps whilst accelerating. Some ppl online say this can be due to bad ground points.

So potentially worth a try to try and clean this up I think?

[Herbie]

8 minutes ago, AFlex said:

So potentially worth a try to try and clean this up I think?

Absolutely.

Use emery paper and/or wire wool and/or a Dremel with wire brush etc. Once bright and clean make sure the connection is tight and put some Vaseline or White Grease on it.

[VFR]

As said remove bolt and pop a small wire attachment on a cordless drill to have that all like new in 10min's, check the bolt hole while its off also & as Herbie said a touch of white grease to finish off.

[AFlex]

Thanks gents. Appreciate the comments 

Any particular grease that you would recommend? I have some WD40 White Lithium grease in a spray can but this comes out a bit watery - mainly used it for door hinges.

Presume you apply the grease on the outside of the connector once it's seated, otherwise it would interfere with making a good connection?

[VFR]

That will do the job & if to watery spray a load onto a flat surface first allowing it to gas off (?) before using a finger to transfer to where you want it.

[steve2006]

Not mentioned and maybe obvious but also clean the connector with a wire brush especially the surface which mates with the earth point, the bolt also would benefit from a good clean or even a replacement if a standard size like M8.

[Spark plug]

I use copper greese on my earth points after a good cleaning up with a wire brush. I think the other end of the bolt is in the strut tower. I would give rusty bolts like that a good soak in wd40 before trying to loosen them

[VFR]

Just be mindful the copper grease is an anti seize product and not suitable for stopping what we see in the pictures above.