Decided I had no excuse not to do my Roadster’s service myself this year (well the majority of it anyway) - just one quick question - how important is dielectric grease when changing spark plugs? I’ve already made several trips to Halfords this week, do I need to make another…?
I guess this is “copperslip” or similar. I would always use it. Just try a local motor factor, they should have it.
Sounds like you’re talking about the copper lubricant to prevent them getting stuck, I’ve got that - I’m wondering about the stuff you can put on the electrical contacts. It’s not mentioned in the Grainger manual, but is on most on-line “how-to” guides.
Not important at all then…
Not copperslip. It has to be electrically insulating.
http://compare.ebay.co.uk/like/150848895818?var=lv<yp=AllFixedPriceItemTypes&var=sbar&cbt=y
Dielectric means non-conductor of electricity. You would use such on battery terminals or to seal HT leads and it could be an ordinary high melting point type grease or a silicone grease.
For plugs it’s wise to use an anti-seize grease such as copaslip or moly grease to stop the threads seizing and tearing out next time the plugs are removed. This can be more likely these days with alloy rather than iron heads and I always use it.
Thanks for replies, I’m concluding I can do without the dielectric grease!
I guess I wasn’t very clear though, I do already have copper-based grease to stop threads seizing, I wasn’t intending to use the dielectric grease for this purpose - the dielectric grease, as the last poster mentioned, is to seal the contact points on the HT leads. Sounds like it’s not really necessary - however I now have to go back to halfords anyway to get an extension bar… (had no idea till I removed the first HT lead that the spark plugs were set so low in the engine!) so may end up getting some dielectric stuff anyway.
Yes the right angle joint as the lead goes down the shaft into the head could do with a bit of it as this can be a point of failure on the leads.l
The workshop manual specifies no grease of any kind on the leads. Anti-sieze (or moly grease) on the plug threads, but that’s all.
If the above post refers to the insulation around the right-angle…if you feel the need to do that, only use red rubber grease as anything else will only speed up their deterioration.
This is good to have around, Servisol Silicone grease high temp and non injurous to rubber and plastics.
Which is basically what dialetric grease is made of!
Goodness me Rich M! £6.49 for 50grms! Go to a builders merchant, 150 grm for under £5. Used for FloPlast gutter seals amongst other things.
Regards Geoff Peace