I know this may sond like a silly question but,
are new spark plugs gapped correctly?.
I am about to service my gsi and the spark plugs have twin electrode arms on them and they are hard to get the gauges in to adust .So are they set correctly.
You are buying the genuine GM ones then?
If so then yes they are gapped ready to go in mate.
However NGK V groove spark plugs are way better, I also used the genuine GM ones until someone persuaded me to try the V groove and ive never looked back.
I am using nkg at the mo, buy i am not sure how to gap the new ones if they need it or not.
The new ones will already be gapped
I'm an NGK V groove convert too.
I used to just use normal NGK, but all thats listed for mine is the V ones. Only a tiny bit more anyway.
Ones I took out were the same. So i guess Volvo use them too, 50,000 miles old (according to the service history) and they still looked quite good.
Re: Spark Plugs
Originally posted by ChrisWood are new spark plugs gapped correctly?.
But its better to check it.
As a sparkplug is not specialy made for your vauxhall, but also sold for ie VW it could be the gap is not exactly right.