Senior Editor Mike Allen offers brief answers to readers' car questions to complement the ones we run in POPULAR MECHANICS magazine.
Q: Currently i own a 2000 hyundai accent GS. It has 26,000 miles on it, new spark plugs bosch platinum (1 spark). Fuel filter changed last september, oil changed still has 1000 miles before next oil change. Cleaned fuel system at shop. Air filter is clean. I live in a tropical climate area. The problem lies in that after an average of 2-3 minutes of turning on my vehicle, if i place it on drive, 2 or 1 it starts to vibrate. It vibrates to a less extent in neutral. If i turn on my air conditioner the vibration gets worse. It only happens if i am stopped, if i accelerate it goes away. My mechanic tried to adjust the timing by raising it to 900 rpm, but the problem doesnt seem to go away. No mechanics in the area seems to know whats wrong, some say it might be the need of a new fuel filter, or the timing belt. Any help would be greatly appreciated. SAMUEL
MA: Try adjusting the motor mounts to find a spot that doesn't resonate.
Q: Since SL quality oil has been changed to SM is there any problem mi and using SL motor oil and SM motor oil together in an engine? Will any engine damage or gum-up occur? Are SL and SM oils fully compatible? PAUL EMOND
MA: Just be sure if you have an SM-rated vehicle to feed it only SM oil. Earlier vehicles will be happy with either or any combination.
Q: I have an 87 Mercury Grand Marquis with a 5 litre engine. The oxygen sensors need to be changed but they are really seized in the exhaust manifolds. Is there any trick or tool to remove these old oxygen sensors? PAUL EMOND
MA: No secret. They do make special sockets to fit better, with a cutout for the leads. After you have one, or at least a socket that fits well after you've cut off the leads from the old sensor, it's simply a matter of cranking in enough torque.