a couple of points about the car
1998 model s40
new coil packs and recently new genuine spark plugs as the non genuine ones that we installed when we did the coil packs failed.
2 litre non turbo motor

he these are two separate issues on idle the car has a lot of engine vibration by holding one foot on the brake and giving it slight acceleration it goes away it has been annoying since we bought the car but hasn't got any better or worse regardless of any other improvements we have made.


the second issue is that we had misfire issues and replaced the non genuine spark plugs with genuine ones and the problem was solved but it is now starting to misfire again and i expect it is probably leads the question is what type of leads do people use and how long do they last?

 

My 2001 ran fine until about 100k miles before it started misfiring and needed new plugs/wires/coils. So, in my humble opinion, it should last another 100k miles before needed the same tune-up. Ummm, good luck. I ended up replacing the coils a 2nd time at about 158k miles.

Your description of the vibration sounds like motor mounts, specifically the bottom 2 mounts. (and luckily, the cheapest of the 4)

 

Are you getting any codes? I've had misfires with map/mat sensor that needed replacement before.

 

what brand of leads do people use?

 

I've used these:

Volvo Spark Plug Wire Set S40 V40 BOUGICORD 112454 1275603

 

Switched to magnecor the other weekend. (Got them from THMotorsports at a recommendation from a dominator on 30forty50)