S70 maintenance - spark plugs and more
January 15, 2011 – 7:02 pmSome cars don’t have easy access to the spark plugs, but that’s not the case with the Volvo S70. All 5 plugs are sitting right on top of the engine under a plate. With the right torx bits, the plate comes off, and you can see the wires that lead to the distributor cap. My car is a 1998 S70 T5, and I guess it’s old enough to have a distributor cap and rotor; I didn’t know until recently that the newer models don’t have them.
The distributor cap is obstructed by the airbox, but having gone through the process of replacing my ABS module, I could probably take out the airbox without looking. It’s simple and doesn’t require any tools.
The distributor cap and rotor both came off easily. One thing that surprised me was that the bolts of the Volvo rotor were not the same as the Bosch rotor. The Bosch rotor required a 3mm allen wrench.
One thing that was nice was that the plastic clip that keeps the spark plug wires together has numbers labeling the wires. The distributor cap also has numbers too. I labeled the wires on my old cap as a reference, but with the numbers on the cap, it wasn’t necessary. It was a good precaution though.
The job wasn’t too bad overall. The spark plugs came out easily. My spark plug socket had a rubber gasket inside, so once I unscrewed the plugs, the gasket was tight enough to hold the plugs as I lifted the socket out of the engine. Without that rubber gasket, I’d probably have to find some super long needle nose pliers to fish them out.
My spark plugs were not gapped correctly. They were at least .03, so I gapped them to .028. Putting the new ones back in was easy too with the rubber gasket. I just popped the plug into the gasket, and then I was able to lower the plug into place. Without the gasket, I would have dropped the plug into place, which would not have been very clean since I put some anti-seize on the threads.
Overall, I’d say this job is a confidence booster for beginning shade-tree mechanics, especially when the car starts up after the job is done.
One Response to “S70 maintenance - spark plugs and more”
So hows it running now with the new electronics?
I’ve tried every plug there is from fancy split, cryogenically treated, platinum and iridium.
Im using the iridium in both the prius (oem) and the ford van and caddie. The super thin wire makes for a nice hot spark and they last forever because of the high temp quality of the iridium.
If you want to squeeze every bit out of the engine, look up indexing your plugs, its a washer set that when used correctly will point the opening in the spark gap at the intake valve. You have to 1. find out where the intake valve is located. 2. mark the opening at the top of the plug where you can see it. 3. install a plug and see where the opening ends up. 4. install the right thickness copper washer to point the gap at the intake valve.
Takes a little practice to get the frist couple done right.
You will be rewarded with a smoother idle, better acceleration, and better milage, some times more than a couple miles per gallon.
As the Caddie uses the lost spark ignition (it sparks every cycle, only needs 4 coils for a v8 motor) I dont know if the volvo does. You have to find the dual iridium plug, it has a little iridium pad welded to the curved wire as the spark jumps both positive and negative, they make them in platinum as well.
As the ignition fires on every stroke (compression and exhaust) it was wearing out the wire and the tip was fine.
The van is a 3-4 hour plug change so I wanted the super long life of the iridium, the caddie just liked the iridium plugs, every bosh platinum (single, double and triple) caused problems from poor idle to noticeable loss in 1/4 mile times.
So I spend the extra for the ngk iridium and change them every 100k, put anti-seize on them if you want to get them back out. Aluminum heads and steel plugs make for dielectric welding and broken plugs.
By David on Jan 17, 2011