geronimo wrote:
> I want to replace the OEM type plugs with premium ones. Maybe Bosch
> Platinum or SplitFire. Whats the best?


Use good old ordinary NGK plugs, I've had great luck with those, the
"premium" plugs are a scam, especially if you have a turbo, my friend
spent weeks trying to track down why his Merkur turbo would start
bucking and misfiring like crazy under boost, finally a mechanic
suggested to replace the Bosch Platinums with plain NGK plugs and the
problem went away entirely. Volvo is not a cheap brand, they chose the
OEM plugs they did because they work well in the application, not
because they're cheap.

James Sweet wrote:
> geronimo wrote:
>> I want to replace the OEM type plugs with premium ones. Maybe Bosch
>> Platinum or SplitFire. Whats the best?
>
>
> Use good old ordinary NGK plugs, I've had great luck with those, the
> "premium" plugs are a scam, especially if you have a turbo, my friend
> spent weeks trying to track down why his Merkur turbo would start
> bucking and misfiring like crazy under boost, finally a mechanic
> suggested to replace the Bosch Platinums with plain NGK plugs and the
> problem went away entirely. Volvo is not a cheap brand, they chose the
> OEM plugs they did because they work well in the application, not
> because they're cheap.

I'm not a fan of Bosch Platinums. Their small electrode tip seems prone
to trouble in some applications. The other makers all have a much more
substantial center electrode in their platinum and iridium plugs than
does Bosch.

John

>>
>> Use good old ordinary NGK plugs, I've had great luck with those, the
>> "premium" plugs are a scam, especially if you have a turbo, my friend
>> spent weeks trying to track down why his Merkur turbo would start
>> bucking and misfiring like crazy under boost, finally a mechanic
>> suggested to replace the Bosch Platinums with plain NGK plugs and the
>> problem went away entirely. Volvo is not a cheap brand, they chose the
>> OEM plugs they did because they work well in the application, not
>> because they're cheap.
>
>
> I'm not a fan of Bosch Platinums. Their small electrode tip seems prone
> to trouble in some applications. The other makers all have a much more
> substantial center electrode in their platinum and iridium plugs than
> does Bosch.
>
> John
>

In this case we decided what must have been happening is the boosted air
rushing into the cylinders was simply blowing out the spark. I can't
think of anything else that would cause it to run as badly as it did.
Idled fine with the platinums but once the boost came up all hell broke
loose.