Dear Tom,
In a recent column at AOL Autos you wrote about oil changes. In the feedback I noticed that there weren’t any questions about changing transmission fluid. I also noticed that a lot of automotive shops only want to change the fluid and not the filter. Is this a good thing?
Delilah from New Orleans

Delilah,
First of all, it is not a good thing to change the oil and leave the old filter. Always change the filter too, and use a high quality one. Scrimping is this area is penny wise and pound-foolish. As far as the transmission is concerned, the fluid is usually changed at 30-36K miles with a new filter. A lot of shops today use a flush machine. This device can suck old fluid out and pump new fluid in without taking the pan off. I do not recommend this procedure. As a matter of fact, flush machines reverse-flush the transmission fluid, sending dislodged dirt and wear particles back into the transmission. I recommend the standard method, and when you have it done, follow the maintenance schedule and change the filter along with the fluid.
Tom

Judy,
It could be due to a bad switch, a wiring problem, or a faulty heating element. There is a technical service bulletin from GM on this problem. It is TSB number 01-08-50-012B. They advise that you check the switch and wiring and if all is okay, then replace the heating element. TSBs are not covered under warranty.
Tom

Marcie,
All I can tell you is that the warranty you bought is probably an extended warranty on Powertrain/Drivetrain administered by a private company. I would closely check the warranty info and contact the warranty company. They should be able to answer any questions you have. I wish you success.
Tom

Pete,
First off, the carmaker doesn’t mention a light that you describe so you’re probably seeing the “Maintenance Reminder” light, which reminds you that it’s time for an oil change. I see nothing in my data that even remotely refers to a “check with dealer” indicator lamp. Read your owner’s manual on the topic “interior information system.” It should tell you what that light indicates. Best to you.
Tom

Randy,
The GM Oil Life Monitor is accurate to within five percent (5%) of oil life; the algorithm monitors engine crankcase temperature, moisture, and combustion chamber events. Monitoring of these areas accurately predicts oil life, so go ahead and follow its recommendation. Just make sure that you properly reset the system it after changing the oil. Success to you.
Tom

Ethel,
Sounds like the compressor is low on refrigerant and oil, or an idler pulley is going bad on the automatic belt tensioner. It shouldn’t cycle so frequently; you probably have a refrigerant leak that is causing the excessive cycling.
Tom

Milt
Power windows have an electric motor, a wiring harness that feeds the motor, and a switch that controls the motor. Either the motor is bad, or there are bad connections, or the wiring harness is broken to that door, or the switch is faulty. My guess? A faulty switch. Have it checked out by a pro to determine the cause.
Tom

Deb,
How ‘bout them Packers huh?! Cooling systems can be checked with a pressure test. During this process, the tech applies air pressure to the system, trying to force a leak at the weakest point. If it’s the radiator, a leak will spring as soon as the pressure gets beyond the radiator’s capacity to hold it. It’s a pretty simple process. Get a second opinion and have a shop perform the test to see what they come up with. Good luck.
Tom

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For more articles by Tom Torbjornsen, visit AMERICA’S CAR SHOW web site: www.americascarshow.com

Tom Torbjornsen is an automotive expert of 37 years. An automotive journalist in good standing with the IMPA (International Motor Press Association) and MPG (Motor Press Guild), Torbjornsen is the Repair and Maintenance Editor for AOL Autos, At Home Portals, and many other websites. Hear his radio show AMERICA’S CAR SHOW, on the SSI Radio Network Saturdays at noon and on Sirius XM Satellite Radio Channel – Stars Too – Sirius 108 and XM 139; Sunday afternoons – 5PM EST, listen to the show on the live stream during regular show times at www.americascarshow.com. Send your car questions to his website at: www.americascarshow.com.

Dear Tom,
Two weeks ago I inadvertently filled my 2004 Toyota Camry’s gas tank with half a tank of diesel fuel. The dealer drained and cleaned the tank and replaced the spark plugs and air filter. The day after I got the car back, the “check engine light” came on, and the dealer said the catalytic converter was gummed up and should be replaced, along with the oxygen sensors. I haven’t had this work done yet. Is it necessary since the car is running well (and there is no rotten-egg smell)? It would cost me over $2,000. Yikes!
Patricia from Vera Cruise, CA

Patricia,
First and foremost, next time you fill up make sure the pump nozzle fits into your gas tank filler-neck before pulling the pump nozzle trigger. The diesel nozzle is larger than the gasoline nozzle; therefore it can’t possibly fit into your gas tank filler-neck. As for the lit check engine light, try running the vehicle for a few weeks in an effort to burn any remaining diesel fuel out of the system. Then have the system reset to see if the light stays off. If it doesn’t, you have done irreversible damage to the catalytic converter and O2 sensor/s and they will have to be replaced. If you don’t like the price quoted at the dealer, get a couple more estimates from reputable independent shops. Good luck to you.
Tom

Carlo,
If I had to cite a weakness on these engines (not the car; overall the car is great), I would have to point to the soft camshafts. The cams in these engines are prone to wearing prematurely. If this was in fact a police car, the engine might be a high performance engine, which would probably have a hardened steel cam and crankshaft. Run the numbers on the engine before buying to verify this. And, as always, have a Carfax Report and a pre-purchase inspection done by a trusted tech prior to plunking down the cashola. Good luck.
Tom

Robert,
Prolonged use of regular gas in an engine designed to use high-test gas will damage the engine over time. A condition called pre-ignition occurs. When the low octane fuel enters the combustion chamber, it pre-ignites before the top of the compression stroke when ignition is supposed to occur. Pre-ignition damages the tops of pistons, face of cylinder heads, and valves. Advise your girlfriend to run the high test; it’s cheaper than engine repair/replacement.
Tom

Sandi,
It could be rod knock inside the engine or it could be an exhaust leak. Open the hood and locate the origin of the noise. Is it coming from the exterior of the engine or from inside the engine? If it is from the exterior, check the exhaust flange where the pipe connects to the exhaust manifold, and check the exhaust manifold itself. It could be a bad flange seal at the pipe, or a blown manifold gasket, or a cracked manifold. If the noise is coming from the inside of the engine, then I would start with an oil pressure test and proceed from there with partial engine disassembly and inspection. Good luck!
Tom

Buddy,
There’s not much you can do other than appeal to the local Ford Zone Rep. Call Ford customer service and contact the Zone Rep directly, because they have the authority to make a decision. Sometimes they are willing to pay for part of the repair. If you have to pay for it or part of it, then get a couple of estimates for the repair and then make your decision. I think you will find that the dealer offers the cheapest deal and the best warranty. Best to you.
Tom

For more articles by Tom Torbjornsen, visit AMERICA’S CAR SHOW web site: www.americascarshow.com

Tom Torbjornsen is an automotive expert of 37 years. An automotive journalist in good standing with the IMPA (International Motor Press Association), Torbjornsen is the Repair and Maintenance Editor for AOL Autos, Edmunds.Com, At Home Portals and many other websites. Torbjornsen is the auto expert of record for Channel 4 WIVB TV, Western New York’s CBS affiliate. Hear his radio show AMERICA’S CAR SHOW, on the Sirius XM Satellite Radio Channel – Stars Too – Sirius 108 and XM 139; Sunday nights – 10PM – Mid EST. Send your car questions to his website at: www.americascarshow.com