Stopping the Shaking May Require Steering Stabilizer

October 16, 2010/Steve Tackett

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

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.

1995 Ford F-15

I suggest you use a factory oil pressure-sending switch from the dealer. There are a few simple tests that can be done to see if the problem is in the dash cluster. Visit the Alldata web site for the way to check the gauge and actual voltage specs. You can also continue with the use of the aftermarket mechanical oil pressure gauge.
Dear Doctor: I have a 2005 Subaru Legacy GT (Turbo). I had the rear oxygen sensor replaced last year, drove 80 miles and it passed inspection. For most of this year the “check engine” light has been on so I replaced the front oxygen sensor. I put 390 miles on it and took it in for annual inspection and it failed. The mechanic said I should put more mileage on it. Codes did not clear yet. How many miles do I have to waste driving around before I pay more money to have it reinspected? Mitch
Dear Mitch: For an engine to set the computer monitors to pass state emissions inspection it has to meet many engine parameters. It is a “must” that the technician have knowledge of the system and use a professional scan tool. He can look at the vehicle computer in mode 6 where all information can be looked at and find the reason why your vehicle’s computer will not set the monitors to allow emissions passing. If there is a pending fault code or a circuit that is out of range, then it is possible that this will hold you back from passing the state inspection.
Dear Doctor: I own a 1994 GMC Sonoma. My air conditioner doesn’t work because the coolant for this vehicle is no longer available. What do you suggest to solve this problem? Ermano
Dear Ermano: The old refrigerant called Freon is now replaced by R134a. It is a simple task to convert the old system over to the new R134a. The problem most technicians have is putting too much R134a in the old system. A good rule of thumb after removing the old Freon and adding the new is to fill the system 75 percent and see how it cools. If the system is working properly then it will blow cool. — Junior Damato, Motor Matters

Junior Damato is an ASE-certified Master Technician.

E-mail questions to info@motormatters.biz

Copyright, Motor Matters, 2010