2002 s60 turbo 60000 miles.....Just bought Bosch platinum plus plugs (saw on another post these were the favored ones) what is the correct gap(manual says .028-.032, torque 22ft. lbs)but Ihave seen different recomendations.
also, I have heard a spark knock in the last few days only during accelleration but not every time( I thought it was just bad gas, but took to the dealer anywayand they said everything was ok just that it has "a hi performance exhaust sound"..... and I was reading a post on gas octane ratings, most guys are using 91????? I thought I read in manual that 87 was ok?

 

87 is ok but 91 to 93 is reccomended.
Espically on the turbo models. I always run mid grade to super in my turbo.
I can notice a major difference in driving between regular and premium.

Gap them to .032

 

Too tight 2 pieces. 1/2 turn past snug. NGK is the spark to go with plat or iri type. Use a stick of hose when installing in order to verify proper thread allignment. Slide the spark top into hose, insert into housing, thread into block until tight, then torque with socket.

 

NGK is a good choice, other good selections are also available such as Bosch, genuine Volvo (I'm not sure if genuine Volvo plugs are OEMed by Bosch or Volvo makes them) or Champion.

Apply some anti-seize compound on the top few threads (closer to the hex) upon installation, and keep everything in-line to avoid cross-threading.

If a torque wrench is not available (you can rent one at an AutoZone for free; you pay initially but as long as you return it within 30 days with receipt, they'll refund), I personally snug it, then give it an additional 1/4 turn for a gasket-typeplugs. For non-gasket type plugs, I usually snug then an additional 1/8 or 1/16 turn (they are usually found on American cars).

Good luck,


JPN

 

As former Volvo sales, here's the skinny: Volvo has an octane sensor, and will automatically adjust timing depending on your octane in the tank. Volvos are designed for 91, but will function down to 87. I personally have an R (high performance S60) and have never used anything but 93 -- but now that gas prices are what they are...

At any rate, I believe 91 will give you optimal performance, although the car will "accept" 87. Still, my guess is, if the car "adjusts" down to 87, you surely will be losing some performance and/or original design characteristics.

...How 'bout it, anyone else? Do you think I need to keep up the 93 on this car? I intend to keep the car for the long term, like my last 240 with 300,000 miles. If I go 91 (as per factory specs) would this be "less clean" to the engine than 93? I'm also thinking of experimenting with a "gas mileage enhancer."