Pat Goss has worked on cars for more than 40 years. He owns a car repair company that bears his name, has authored numerous books on auto maintenance, and makes weekly appearances on Motorweek, a PBS television program.
He visits right here once a month to answer questions about fixing your car.
The transcript follows below.
Editor's Note: Washingtonpost.com moderators retain editorial control over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.
Silver Spring, Md.:
I have '98 Lexus ES 300, w/100k. During a regular tune-up, I wanted to replace the fuel filter and spark plug wires. The dealer said the fuel filter and the spark plug wires are good for the life of the car. I have kept up with all the timely maintenance. What is your opinion on the fuel filter and wires issue? Love your show.
Pat Goss: Spark lug wires should be replaced on an as-needed basis not time or mileage. Although it is doubtful they will last the life of the car they could conceivably have considerable life left. The fuel filter is not that way though. In an ideal world fuel filters should be changed once every year. This is due to the fact that as they accumulate dirt the forces exerted on the remaining filter material become dramatic and often cause particles of filter paper to become dislodged leading to failed fuel injectors and other costly problems.
Shawnee, Kansas: I have a '97 Monte Carlo with 81,000 miles. I recently took it in to Goodyear to have the right front wheel looked at b/c it's making an odd grinding noise that I can feel through the floorboard when I make left sweeping curves (like on the interstate). They told me that I will probably need to have the barrings replaced, but they couldn't guarantee that would fix the problem.
My question to you is how difficult could it be to find a grinding noise in wheel? Could it be the barrings at 80k miles?
Pat Goss: Certainly the noise could be coming from a failed bearing but it could also be coming from a "cupped" tire or a drive axle. Begin by rotating the tires and see if the noise changes or goes away. If there is a change it is probably tire wear and nothing more. If the noise remains substantially the same it is highly probable that it is a bearing.
Reston, Va.: I have a '94 Ford Explorer XLT. On cold days, after the car has been driven a few minutes, I get a chirping or whistling noise. Could this be my belts?
Pat Goss: Very probably is the belt or related to the belt. When it starts making the noise use a spray bottle with a plain water to spray on the belt. If the noise goes away for a few seconds then returns and the spraying several times yields the same result the problem is related to the belt. Check the belt tensioner, belt, and the pulleys.
Herndon, Va.: There is a new advanced formula BG additive for the crankcase and gas tank.
Which is better... BG 44K or the new advanced formula?
Pat Goss: When BG puts the word advanced on a product it means it has in some form been improved.
Canberra, Australia: I have a 2001 BMW 325CI manual. Since new I have found it difficult to achieve a smooth acceleration from rest in first gear, the car appears to surge with the initial application of throttle, dies briefly and then accelerates normally. It is also more likely to stall than most cars I have driven.
The dealer claims this is due to the motor still being tight but after 65,000 kms I find this unlikely.
Pat Goss: The dealer is feeding you a story. For some reason they don't have the knowledge or inclination to check the car. They should connect the car to an engine analyzer and a computer scan tool. By looking at the patterns on the oscilloscope (engine analyzer) and the data stream from the scanner they can tell if the computer is not enriching the fuel properly or if the engine can't use the properly enriched fuel. If the computer does not see the correct signals from the sensors it will not deliver enough fuel and the car will hesitate. If the ignition system is not capable of producing the correct amount and duration of high-voltage spark to burn the fuel the engine will hesitate.
Washington, D.C.: Good Morning Pat,
Great show, I listen every weekend even though it drives my wife nuts.
I'm thinking about switching to a K&N air filter not so much for performance but just so I won't have to buy anymore air filters. I'm thinking of the one that can be cleaned over and over. I plan to keep this car until it dies (2000 Accord). Is this a good product and is it a sound idea?
Pat Goss: K&N makes a very high-quality filter. It can be used over and over but does require periodic maintenance. It has to be removed washed and then recoated with a special air filter oil. You have to be very careful not to get too much oil on the filter as this can lead to a failure of the MAF sensor. So BE VERY CAREFUL!
Atlanta, Ga.: What could cause a car's gas mileage to drop seriously in 6 months? I have a Passat with 85,000 miles on it, and it used to go 350 miles on one tank of gas (about 15 gallons); now we're lucky if it goes 200 miles. We've checked the thermostat and the coolant and the computer codes and everything seems to be fine.
Pat Goss: Have you checked the ignition system? Spark plugs, wires, coils? All such items have to be in good operating condition. Is the air filter clean? Are there vacuum leaks? Is the fuel pressure correct? Are the oxygen sensors functioning properly? Is the mass airflow sensor generating a proper signal? Is the air charge temperature sensor reading correct ambient air temperature? etc, etc... These are the basic, after that it gets complicated.
Mobile, Ala.: Dear Pat,
After having rotors turned, new pads, the car now sounds like a garbage truck when stopping? Comments, suggestions?
Pat Goss: Wrong turning procedure. Rotors too rough or too smooth. Failure to apply non-directional finish after turning complete. Using untreated old pads with the newly turned rotors. No sound dampening materials on the brake pads. Improper lubricant used on the brake calipers.
Sunflower, Ala.: Dear Pat,
I'm considering the Chevrolet Avalanche Z71. Any exhaust/intake upgrades to improve the 19 on the highway? Any brake changes to improve stopping distance? Thanks.
Pat Goss: All kinds of modifications available. Wonderful brake kits available from two or three manufacturers. Expect $4-8000 for the brakes. Exhaust and intake upgrades could probably raise full mileage to about 20, and would cost about $3000.
Washington, D.C.: Do most garages offer free car "check ups"? We feel like we're probably in need of new belts, brake pads, and god knows what else. Occasionally we'll smell burning or sulfur-like emissions from the dash.
Are there any honest mechanics in Northern Va. that you could recommend that won't use this as an opportunity to completely take us to the bank? We've had problems like this before, where we'd get two opinions where the second would end up being a fraction of the first (which insisted that thousands of dollars in work was needed). Unfortunately, the mechanics we dealt with in the past specialized in German cars, and we're now driving a Toyota.
Thanks for your help.
Pat Goss: Some shops do offer free checkups. Most offer 1 or 2 as a special at certain times of the year. Are there any honest mechanics in Northern Virginia that I could recommend, yes, absolutely. But with your attitude toward technicians, I wouldn't recommend them.
Arlington, Va.: I am getting ready to sell my car and was trying to determine a price. Looking at the Blue and NADA books the private party prices vary widely. What are the differences and is one preferred over the other? Thanks!
Pat Goss: All book prices are only a guide. No book guarantees a price. The absolute value of any vehicle is determined by what the seller will accept, and what the buyer will pay. Above and beyond that, pick a book value that you feel is correct and if you get lots of comments that the price is too high, expect to lower the price to sell the vehicle.
Silver Spring, Md.: I have 1994 & 1997 Mercedes-Benz E320 and want to know is it o.k. to use Mobil 1 synthetic oils? Do they improve performance? How do you change over? Do I need to flush the engines in order to switch from mineral basis to synthetics?
Pat Goss: Not only is Mobil 1 okay. It is recommended for Mercedes automobiles. Using Mobil 1 can significantly increase the life expectancy of any engine. You do not need to flush or perform any other maintenance prior to change over.
Washington, D.C.: I have a '96 Ford Explorer. It currently has a blown head gasket, or so I think so. Thick white smoke is coming from the exhaust but the car is still running. It also needs a new transmission. What do you recommend?
Pat Goss: Needs head gaskets and a transmission? Because the 96 had one of the most durable engines in the world, expect yours has extremely high mileage or has been severely abused or neglected. Any combination of the above suggests it would be better to get another vehicle.
Arlington, Va.: Is there such a thing as an oil filter pump that goes on a '95 Land Rover Discovery?
Pat Goss: If by oil filter pump, you mean a pre-oiler; yes there would be. Most of them are universal and fittings are made up at the time of installation.
Germantown, Md.: Just bought a 2005 Toyota Corolla "S" that has the Lojack tracking device. A week or two after driving off the car lot, I started having trouble getting the car to start. I'd turn the key and the car wouldn't turn over. This happens at least a couple times a week. I took the car in a week ago only to have the service people tell me they couldn't find anything wrong. The next day it happened again. Could it be that the starter has gone bad on a brand new car? Or could the Lojack have anything to do with it?
Pat Goss: Unless there is something in addition to the Lojack system there should be no relationship. Lojack is purely a tracking device. If the dealer added a starter interrupt or other type of anti-theft device along with the Lojack, that is where you would look first.
Anonymous: I have a '97 BMW 328i with 15 inch rims on it. I want to upgrade to 18-inch rims. Will that cause any problem with my car speed tech or anything else?
Pat Goss: If you do your plus sizing correctly you should be able to maintain reasonable accuracy. But look out, that means you're going to an extremely low profile tire. Probably a 30 or 35 series, which will produce a punishing ride, extreme tire wear, and high susceptibility to road hazard tire and wheel damage.
Annapolis, Maryland: When do you need to have a wheel alignment... I have an all wheel drive (36K) and front wheel drive (195K) and the dealer says I need one... what are the chances of that?
Pat Goss: You need a wheel alignment when one or more tires is worn more on one side of the tire than the other side of the same tire. If you are rotating tires properly, you may never need an alignment.
Trenton, New Jersey: 1992 Honda Accord EX Sedan. About 170K miles on it, still runs great, still running the original brake rotors, front and rear. Assuming they are under the minimum spec., what is the correct procedure to replace the front rotors? Are they pressed on? What type of equipment and questions do I need to ask a shop to make sure it's going to get done right the first time?
Thanks for your time.
Pat Goss: Honda uses two types of rotors, one pressed, one bolt on. The pressed type will require a hydraulic press, proper press adapters, wheel bearing repacking equipment, and a good knowledge of the procedure. If you don't know what you're doing, not only will you destroy the new rotors but the bearings and the steering knuckle as well.
Charlotte, N.C.: I recently purchased a new 2004 Pontiac Vibe. The engine revs up to 1,800 rpm from a cold start. The dealer's engine analyzer says the engine is running to factory specification.
Is this rpm level going to cause future transmission problems from shifting out of PARK to reverse or drive?
Pat Goss: 1800 does not sound that high. Most cars will run between 1200 and 1800 when cold. Unless the car thumps or doesn't something violent when it is shifted into reverse or drive, the speed is not cause for concern.
Wheaton, Md.: We just bought a 2000 Grand Caravan that has been using synthetic oil by the previous owner. Is this something that needs to be continued (we are not used to using synthetic oil and have been owners of many Caravans) or can we switch to good quality real oil? If so, what method is preferred?
Pat Goss: If you're happy with the cheap stuff and the loss of protection synthetic provides, then switch back to conventional.
Clifton, Va.: Use of K&N air filter in some cars will void the warranty.
Pat Goss: Only on a couple of components.
Arlington, Va.: Mr. Goss,
I recently purchased this oil additive that you are supposed to mix in with your engine oil right before changing the oil. What are your thoughts on this? I don't remember the specific name but it claims to clean the parts, etc. Is this sorta like a very cheap version of a BG flush? The bottle cost like $4
Pat Goss: I have no idea what it is. Good, bad, indifferent, damaging. One thing's for sure, for 4 bucks it can't do much.
Gaithersburg, Md.: How often do you recommend adding a can of 44K to the gas tank?
Should I use a can of their fuel injection cleaner system as well?
Pat Goss: 44k should be used every 7,500 miles. It is a fuel injection cleaner. The best of their fuel injection cleaners. No you do not need another cleaner.
Great Falls, Virginia: Dear Pat: My 2001 Chrysler Sebring (38,500 miles) has suddenly begun to make a high-pitched screeching sound while in motion. The sound starts and stops but can start again once the car is warmed up. It is not constant and does not occur if the car is stopped. Seems as if the sound is coming from the left front tire but it's hard to tell while driving. Our mechanic said it was not the brake shoes and the only way to discover what it could be is if he could hear it himself. There is a great deal of "carbon" around the rim of the front wheel hubcaps - more on the left than the right one. The mechanic says that is normal and more noticeable because of the design of the hubcap. What do you think it could be? (I did have the tires rotated some weeks ago)
Pat Goss: I think you better have somebody else check the brakes. More brake dust on the front wheels than the rear wheels is normal. More brake dust on one front wheel than the other front wheel is not normal.
Bethesda, Md.: Good morning, Pat... hope you can answer my question.
I have a 1993 Jaguar XJ6 that is used maybe once a week (if at all), and it's garage-kept. It seems when I skip a week without using her, the battery has a tendency to drain out... and I end-up having to jump-start. Usually I get her started during the week (just sitting in the garage) to let the battery charge, but when I'm away for weeks, by the time I get back, it's back to drained. Anything you can recommend to fix this? Thanks
Pat Goss: Sounds just like my Corvette. I use a battery maintainer to prevent the problem. A battery maintainer is not a trickle charger. Expect to pay about $40-80 for a good maintainer.
Falls Church, Virginia: I have a 1990 Honda Accord LX. A few days ago I had some maintenance done on it. Nothing major... just the radiator and transmission flush. The next day the S light came on and speed went sluggish the first of couple minutes. I had it checked out at the local garage and the person told me that I would need to get a new transmission for $2000. Is that true, I just had a rebuilt transmission put in 4 years ago. Please advise.
Pat Goss: Not normal. Shouldn't happen. First thing to do is to determine that the proper Honda fluid was used during the transmission flush. If a generic fluid was used, that could be the problem. If it was generic it will be imperative to have it flushed again immediately, this time using proper specification fluid.
Silver Spring, Md.: I have a 2003 PT Cruiser with 19,500 miles on it. Sometimes when I come to a complete stop, and then accelerate; my brake light comes on for about 5 to 10 seconds. What should be checked?
Pat Goss: Check the level of the brake fluid in the master cylinder. Sounds like its low.
Annapolis, Md.: At 30,000 miles should I get my transmission fluid changed?
Pat Goss: No. But your overdue for a transmission flush. And remember a change is not a flush. Only transmission fluid flush is acceptable on newer cars.
Arlington, Va.: I have a 2002 Volvo S80 with about 55,000 miles, which I have faithfully maintained according to dealer recommendations (oil change every 7,500 miles). I now understand that might not be enough to promote longevity. Is there any value in starting more frequent oil changes or has the damage been done?
Pat Goss: Unless there is documented engine damage. I doubt it, at so low mileage. Stepping up the oil change interval could have significant benefits. For highway driving 5,000 miles. For short trip city driving 3,000.
Wheaton, Md.: Please excuse the naive question... I am and interested but not informed female. What are the benefits that a synthetic oil gives?
Pat Goss: Aah, a sensible question. Few people know the answer. Most are too shy to ask. The benefits of synthetic oil are greatly increased resistance to breakdown from heat. Enormously reduced friction (the less friction, the longer the engine will wear), sometime slightly improved fuel economy. Overall far better lubrication qualities. These characteristics is mandatory in several new cars: Corvette, Mercedes, Porsche, etc.
Falls Church, Va.: How much should it cost to replace the u joints on a '97 F150 truck?
Pat Goss: I don't have an idea in the world whether you're truck is 4 wheel drive, 2 wheel drive, which style drive shaft it has, what the gvwr rating is, or what information would be necessary for a serious estimate. A highly generic one is $250.
Manassas, Va.: I am noticing a quick rattle or vibration when my automatic transmission is shifting. I can avoid this noise by accelerating very slowly. I don't feel anything -- only hear the noise. Any ideas? P.S. It's a '94 Nissan Pathfinder.
Pat Goss: Check the heat shields on the exhaust system. Common problem, usually repairable by installing hose clamps around the heat shields.
Manassas, Va.: Joe from Manassas... the driver's front and passenger front power windows on my '91 Buick LeSabre go up and down extremely slow. Sometimes they won't move at all and I have to wait a few minutes before they will move again. What can I do to fix the problem?
Pat Goss: Try applying silicon spray lubricant, to the window guide-channels which may help. If it doesn't it may be necessary to check for high electrical resistance in the power or ground circuits to those windows.
Anytown, USA Pat,
I have a 2004 VW Golf with 2.0 engine and 4 speed automatic. VW says never change the transmission fluid. No dipstick to even check the level of fluid. I pressed them, and they said they can change it, but it is over $300. They say it is "lifetime" fluid.
Can this be true? In a VW?
Pat Goss: Could be. Well sort of. That is 100,000 miles lifetime. Most European manufacturers use two different types of transmission fluid. One is , a more or less, conventional fluid; the other is an extremely costly hydraulic fluid. It has been our experience that most of the basic VWs use a conventional transmission fluid. The flush is a little bit more expensive if it would be on a car with a dipstick because a computer scanner has to be connected to the vehicle to aid in checking fluid level. Still not a big deal though.
Germantown, Md.: Good Morning,
I have a 2004 Acura MDX and I am looking to purchase a set of 20 inch by 8.5 inch wheels and tires. Since I am plus sizing, are there any concerns I should have regarding the 4WD system? What should I make sure the tire shop does to ensure a proper installation of the tires and the tire pressure monitoring system?
Pat Goss: First you don't have 4 wheel drive. At this point doesn't make a 4 wheel drive anything. Although they elect to somewhat mislead people by calling there systems four wheel drive, they are actually all wheel drive. The only concern regarding the all wheel drive system is that all 4 wheels and tires be the same size. Any good tire shop will know the proper procedures and have the proper installation tools. It does require a special tire installation machine. The tire pressure monitoring system may or may not work because it is calibrated to the original recommended pressure. You will probably be looking at lowering the pressure, which could upset the system.
RE: Switching back to conventional oil: You did not answer the second part of my question. So if we make this decision, we just change oil type at the next oil change?
Pat Goss: Yes.
Washington, D.C.: You wrote: "Are there any honest mechanics in Northern Virginia that I could recommend, yes, absolutely. But with your attitude toward technicians, I wouldn't recommend them."
I didn't realize I had an attitude about technicians. I told you how we've been burned in the past and then I asked you if you could recommend an honest mechanic in Northern VA for Japanese cars. Where's the "attitude" you speak of?
I think you're being a bit touchy and overly sensitive today!
Pat Goss: I'm not even a little bit touchy or overly sensitive, just realistic. If I recommend some one to a shop that I believe in, and that person winds up being a problem, I hear about it in no uncertain terms. Based on your comments and the fact that something has to be dramatically wrong for any individual to encounter sufficient numbers of problem shops to have ongoing repeated issues of dishonesty I take the cautious route. Sorry.
Arlington, Va.: Pat,
Last chat you assisted me with a question regarding no spark in my '91 Accord. It came down to a bad distributor coil. The weird thing was we tested the old coil and it tested fine. Is this common?
That same '91 Accord w/ 142K (still with the original clutch!) is having trouble starting. I am telling myself b/c it's been very cold and the gas in it is very old. I replaced the spark plugs, the cap/rotor, igniter, and battery myself. Yet it takes about 5 seconds of cranking before it starts. Any suggestions? I love this car and want to keep it running as long as possible. Other suggestions in general to keep it going for a long time? Thanks.
Pat Goss: This is not uncommon due to the fact that as a do-it-yourselfer you probably could only measure resistance. Resistance measurements on coils often only tell you when a coil is absolutely, totally, completely shot. Resistance frequently will not show a coil is extremely weak. That's why we use oscilloscopes.
If it's carburated check the choke, if it's fuel injected check for proper cold enrichment.
Arlington, Va.: I have a 1998 Toyota RAV4 with just under 40,000 miles. My dealer is recommending that I replace my timing belt now.
I thought that this was not done until the 50K - 100K mile point. At my mileage rate, that could be at least another two years.
Is it advisable to replace the belt now? And, if so, should the water pump also be replaced, even though there's no sign of water pump problems?
Pat Goss: Timing belts like other rubber products are replaced based on time or mileage, whichever comes first. Disuse often is more damaging to rubber parts than use. The generic recommendation would be 90,000 miles or 4 years. You are almost double the time allowance. The dealer is on target.
Charlotte, N.C.: Hello Pat.
I just purchased a 2005 Toyota Tacoma. It has a 4.0 Liter V6 engine. The manual says to use "premium" gasoline. Should I be using 91+ octane, or will the 89 octane suit the Tacoma just fine? I have been using the 89 octane. Do you have any other suggestions to keep the engine humming?
Thanks! Josh in Charlotte
Pat Goss: Most Toyota manuals say for best performance use premium gasoline, of at least 91 octane. If yours is phrased you should have an 87 octane engine. Which will save you a lot of money.
Alexandria, Va.: Pat, I love your show and your info. I have a '99 Honda Accord. The check engine light comes up with an engine code that says the catalyst system is operating below threshold. However, if I reset the system by removing the appropriate fuse, the light goes off. This has happened twice. What should I do? Thanks for all of your help!
Pat Goss: The light is trying to tell you that you may have a bad catalytic converter, a bad oxygen sensor, or may be something much more basic like a vacuum leak.
Springfield, Va.: My daughter drives a 1989 VW Cabriolet (that she has painted PINK)... she's good natured about driving an older car in a "new" car society; however, there's one reoccurring problem and no one seems to be able to know what causes it. On very cold days, her car starts roughly and then once warm and she drives off the top speed is maybe 15 mph. It is very embarrassing and she'll have the accelerator to the floor. I have driven her car and had a similar experience but it doesn't happen with any regularity. When we take it to the car guy he will say he can't recreate the problem. So... any ideas? I tell her make sure that her gas tank is always full (in case its a "not enough gas getting to the engine" problem) and we always tell her to warm her car up first... but other than that, we're fresh out of ideas.
Pat Goss: Sounds like a overly rich fuel condition, which could be the result of improper fuel pressure, or dirty fuel injectors, improper fuel delivery due to incorrect signals from one of the computer's sensors. Begin by checking the air flow meter.
RE: Golf trans. fluid: So, if the VW Golf belonged to you Pat -- would you wait until 100k miles to have the fluid changed? Or would you change it sooner, even though it's expensive and more complicated?
Thanks, really appreciate your help! I want to make sure the car lasts a long time without an engine/transmission rebuild.
Pat Goss: First, I didn't say it was expensive. In most cases it has been my experience that the more common VWs use a conventional fluid. Not the $8-10 per pint hydraulic fluid. The only difference is about $15 to connect a scanner for the final fluid level adjustment. Would I do it? Absolutely. If by some strange coincidence have hydraulic fluid in it, I would wait the 100,000 miles, but I don't think that's the case.
Arlington, Va.: Pat,
Recently, I went to a service station for a VA Safety inspection. After several hours of waiting they called to let me know that I needed a break light and a headlight alignment. While I'm not able to confirm the headlights needing work, the break light was functioning fine when I got in line. The service station wanted $30 ($10 a piece) on top of the labor charge for an oil change I had already requested, and of course the Va. inspection fee. When I got there I played with the headlights (seeming fixing one - which was inspected as ok) and popped in a light bulb (which had been given to me gratis by a gas station on the N.J. Turnpike last year). This obviously upset the people at the service station.
So all I had to do was "pay" $10 for someone to turn the other headlight adjustment screw for about 5 seconds. My own "adjustment" wasn't adequate.
Is double dipping for hourly labor charges the norm? and how would you suggest someone could prevent being "extorted" for suspicious repairs? I'm not saying someone tampered with the car, but like I said the light worked fine before it got to the station.
Pat Goss: Why did the station in NJ give you a gratis brake light bulb?
Potomac, Md.: Pat:
Can you explain how traction control systems work, and if one can tell whether or not TCS has activated while driving?
Pat Goss: There are several variance on traction control. However most share at least one thing. If a wheel starts to spin the abs system applies the brake on that wheel to control the spinning. Additionally some systems have the ability to reduce throttle setting (to cut back on power), they can also retard ignition timing, and some can even deactivate cylinders. All to reduce power to the drive wheels. Most traction control systems signify operation by flashing a yellow traction light when they're controlling traction.
Elkridge, Md.: Pat,
I took my 1996 Pontiac Sunfire into a dealership for service and was told that the head gasket was "seeping oil" and that while it didn't need to be immediately replaced, I should keep an eye on it. Does this sound right to you? Thanks.
Pat Goss: Very common. Lots of head gaskets seep oil. Until it starts to leave puddles of oil on the ground, it is absolutely nothing to worry about.
Maryland: What are your thoughts on the new Ford Escape Hybrid. What type of maintenance is required for the batteries?
Pat Goss: If you have the need and if you need most of your driving is stop and go. Hybrids are wonderful. Remember that the hybrid fuel economy advantage is in town, where it runs mostly on the electric motor rather than the gasoline engine. Frequently a hybrid will get significantly higher miles to the gallon when driven in the city then when in driven on the highway. Essentially there is no battery maintenance until replacement time.
Pat Goss: Thank you everyone. See you next month. Be careful if it snows. Drive gently, Pat.