Hey there.

I just had the spark plugs in my 2000 S70 GLT changed with (FR7DC) Bosch Super (copper) plugs at PepBoys (only because I couldn't loosen the damn cover's '*' screws myself). The old (Volvo) plugs seemed to be working fine but I'm at 60,000 miles so I figured they should be changed as per the schedule. Since these new plugs have been installed, I've noticed a burning-oil smell when the car is idling with the air vents open. The tail pipe exhaust doesn't smell like burning oil and there is no telltale cloud but the car exhaust doesn't quite smell like it did before (kind of a caustic, sulphur, citrus smell). The engine appears to be running smoothly and there is no excessive steering wheel shake when idle. I have not changed octane levels, gas stations, or anything like that.

To give you some additional background, a few days before changing the plugs, the car was at the Volvo dealer getting some other work done (ECC repair, brake fluid change, state inspection and 60,000 mile inspections). The car passed state inspection and the 60,000 mile inspections showed no leaks, cracks in pipes/hoses, etc.). I changed my oil weeks ago (myself) and did not spill any oil. I also have not added any oil since then. A quick visual inspection of the engine and a look under the car show no sign of leaks or spills. The oil cap is tightened firmly, the dip stick is in place, and the oil level (as per the dipstick) is the normal color/level.

Could the new park plugs be causing the problem? If so, what should I tell the non-Volvo mechanic to look for/do when I return the car to him to correct this problem? If these plugs are the problem, what other plugs should I tell him to replace them with?

Thanks for your assistance.