Dear Doctor: My grandfather gave me his 1995 Ford F-150 Flareside pickup that has 85,000 miles. It’s a great truck, except that occasionally while driving over some minor road bumps the front end will start shuddering violently. It usually only happens when going over 40 mph. The only way I can stop it is to get on the brakes — hard. The shocks on the front end were replaced one year ago. Any insight would be greatly appreciated. Ben
Dear Ben: You need to make sure all the front-end parts (wheel bearings) are in good condition and that the tire pressure and tire size are correct. We also recommend the use of a factory steering shock stabilizer that connects between the frame and steering center link. Even if your truck does not have one, you can order the attaching hardware from your Ford dealer parts department.
Dear Doctor: We are the original owners of a 2000 Mazda Miata with 56,000 miles. Sometimes it runs rough and the “check engine” light flashes. We took it to our garage and it shows a misfire code, so we put new plugs and plug wires, but it did not fix it. Our garage says until he hears it running rough he is at a loss as to what it is. Could it be a coil? It would probably be a $500 part and labor gamble. I don’t want to change parts for the sake of changing parts and not fix the problem. What’s your advice? Walt
Dear Walt: Multiple and random misfire codes usually equal a spark problem. Ignition coils are very common on this car. Have your technician check with Identifix and also look on the Alldata web site for a history of problems listed on this car.
Dear Doctor: I have a 1997 Jeep Wrangler with about 83,000 miles. When warmed up and resting at idle the oil pressure gauge drops to 0 and the warning buzzer goes off. When engine speed increases the gauge registers normally again. I had the sending unit replaced and an auxiliary unit attached. There is plenty of oil pressure in the engine. I’ve been told the problem is in the gauge or the dash cluster. I don’t want to spend great amounts of money. Is there another place I should look, or should I just hook up an auxiliary gauge and forget the one on the dash? Brian
Dear Brian: As long as the oil pressure is at specification with a mechanical gauge then your engine is safe.