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.
I have a '99 Silverado with a 5.3L with 140,000 miles on it. I have been using Mobil 1 and BG 44k for the last 60,000 miles or so. On cold starts during the winter I have a tapping coming from the engine that gets louder/softer with increases/decreases in engine RPM. It goes away after driving a few hundred yards (distance goes up or down depending on how cold it is outside). What is causing this? Is it worth fixing? What is your estimate on the repair? This is the only problem I have had with the truck. Thanks. Love your show on the weekends. I have been listening since I moved to the area a few years ago.
Pat Goss: This is most likely the chronic "Piston Slap" problem Gm has been experiencing with their 5.3 engines. GM says (in a TSB) that it will not damage or shorten the life of the engine and they will no longer cover repairs even when the vehicle is still under warranty.
So far this has been the case. We generally do not recommend attempting any form of repair. If you do elect to attempt a repair be warned it is VERY expensive and there is no guarantee it will not still be there or come back.
Lake Grove, N.Y.: I have a '02 Hyundai Sonata 2.7 ltr., automatic. Can I run synthetic trans. fld., (redline D4) also do I have to remove the intake runners to install spark plugs? Or any other special procedure?
Thanks, Bill Cook
Pat Goss: You can run synthetic as long as the product you select ABSOLUTELY MATCHES the vehicle specification requirements.
Can' tell you about the intake runners. That is usually determined by looking at the engine and determining if the plugs can be reached without removal of the runners. Some can some can't.
Lockets, Va.: My 1997 Jeep (lots of miles) within the last week has started not accelerating -- the rpms go way up the car doesn't accelerate.
I put some gas additive through it that seemed to help a bit but I think it was my imagination.
Any ideas aside from taking it in for a tune-up?
Pat Goss: If the engine revs but the vehicle doesn't move at an equal speed the problem is typically due to a bad transmission or in rare cases a fault in the transfer case (depends on system).
Rockville, Md.: Hi Pat,
I've noticed that when driving my 93 Camry, there is a clicking sound. The clicking is more rapid the faster I go. It sounds like the clicking one hears when a CV joint is going bad except I hear this sound when driving in a straight line. Any thoughts on what this could be? Thanks.
Pat Goss: Start by checking the cv joints. When they're really bad they make noise all the time not just when going around corners.
Beltsville, Maryland: Pat,
Our daughter's 2001 Mazda Tribute has experienced a sudden drop in fuel economy and we are looking to you for some ideas as to what may have caused this. Not really sure how long ago this started, but I know that I was getting 17-19 MPG in local driving before I gave her the car late last year. With the last 2-3 tankfuls she is getting something around 12-13 MPG. With the cost of gas being what it is this is not insignificant.
The car is regularly serviced with Mobil 1 and I have had most of the BG services performed over the past 18-24 months.
Pat Goss: First order of business is a test drive paying particular attention to the position of her right foot. We frequently find folks driving harder as they become more familiar with the vehicle. If nothing is found with driving style. Check the operating temperature of the engine. Could be a bad thermostat. If the operating temperature is correct check the signal from the coolant temperature sensor to the computer. It may not be relaying the proper temperature.
Gaithersburg, Md.: Dear Mr. Goss,
I have a 2000 Volvo V70 wagon (manual transmission) which runs fine except for one problem. Whenever, the car speed is lower that about 25mph and the car in neutral, engine RPM drops to around 500 instead of the 850 that it really should be. Once the car comes to a full stop, RPM comes back to 850 very promptly but not before the car comes to almost full stop. This problem is worse in the winter months than during summer months and has existed for the last 2-3 years without unduly affecting the cars performance and fuel efficiency. Dealer has not been able to find anything wrong. Have you heard of this from others before? Any ideas would be appreciated. Thanks.
Pat Goss: Begin by inspecting the basics. That would be looking for varnish buildup in the throttle body and idle air control (AIC). It only takes a very small amount of varnish to create problems. If nothing is found with either you will need to find computer strategy for the vehicle. With computer strategy you will know what the computer is relying on when vehicle is moving and when the vehicle is sitting still for idle control. Once that is known you can test the individual components that help maintain idle control.
Alexandria, Virginia: My 2002 VW Jetta (v6) has endured the engine coil replacement. Recently my engine light came on and the dealer replaced "two black sparkplugs" but said the engine coils were not to blame.
I've never known a car to have 2 black plugs and there be no cause. Shouldn't we be looking for something?
Pat Goss: Yes, you should be looking for coil output, coil oscillations, and fuel mixture on the two effected cylinders. The dealer may not be able to do this, as it requires an exhaust gas analyzer and an oscilloscope.
Deale, Md.: Pat,
I have a 1990 Porsche 944 S2. The other day I was driving -- going about 40 mph or so -- and the battery gauge went to zero and the RPM gauge started to jump up and down and then it just quit. Can you give me some ideas of things to check into?
Pat Goss: As with all electrical problems, begin by testing the battery, then the battery cable connections, then the alternator. The alternator must be tested for amperage output voltage limit setting, and diode/stator condition.
Springfield, Va.: Just purchased a '02 Toyota Camry. Yesterday, was told by a co-worker, that Camrys have a problem with oil leaks, which cause the engine to seize. Is this true and what should we do about it?
Pat Goss: Any engine can have an oil leak. Any oil leak can cause an engine to seize, but only if the driver is not following the rules. Oil level needs to be checked regularly. Regularly means every time you fill the fuel tank. However we don't see any more oil leaks in Camry's then in other vehicles. What we do see is oil breakdown and sludge formation caused by poor oil change habits and failure to service the pcv SYSTEM.
Silver Spring, Md.: Hi Pat,
First and foremost, let me start by thanking you for providing such a great forum for us to discuss our car questions.
I have '98 Lexus ES300 with about 102k miles. I have kept up with all maintenance at the scheduled interval. Lately I have noticed losing power and hesitating, its like I am hitting a wall when I reach the 60mph mark. The only thing I haven't replaced is the fuel filter, which the dealership has sworn lasts the life of the car. Do you think replacing the fuel filter is the resolution? And if the problem still persists, how should I go about diagnosing it.
Pat Goss: Fuel filter certainly can be the cause. Even if fuel filters last the life of the vehicle, vehicle life is considered to be 100,000 miles (for the purpose of lifetime parts not the total life of the vehicle). If you really wanted to take care of a vehicle, you would change the fuel filter every year unless it is mounted inside the fuel tank. To determine if it is the fuel filter, check fuel pressure at the speed at which the problem occurs. If the fuel pressure is low then suspect the filter or possibly the fuel pump. If fuel pressure is normal check the mass airflow sensor/meter.
Bowie, Md.: Hi Pat, We own a '98 Jeep Wrangler Sport with a five speed manual transmission. About a month ago we noticed that when you first take the car out in the morning, the engine would seem to lose power when you step on the accelerator. Instead of accelerating, the RPMs would drop down and the car would sound like it was about to stall. It would sputter and backfire. Then after about 20 seconds it would "come back to life". This would keep happening periodically for the first 10 minutes of driving in the morning. Once the car gets warmed up it seems to go away. So now we let it idle in the driveway for 5 minutes before driving it. While it is idling in the driveway, the RPMs will continue to do the same thing as when you are driving it. They will dip down below the 1,000 and sound like it's about to cut off and then rev back up to normal idle, then dip back down, then come back up, etc. until it warms up. We have tried two different mechanics and the dealer. No one has been able to diagnose and fix the problem. They have tried a tune up; replaced the computer module that controls the fuel and the air temp sensor; and checked the module that works the idle. Any other ideas?
Pat Goss: Check for varnish buildup in the throttle body and on the idle air control (AIC). These are normal service items and account for more than 90% of erratic idle problems. Stalling or severe hesitation in your case is often the result of carbon buildup on the intake valves. I suggest before spending more money that you use a container of strong fuel injector cleaner such as BG 44K in the fuel tank.
Washington, D.C.: I am getting a 1997 Dodge Neon from a co-worker. The Neon needs a gasket, is it worth it, or should I just wait? And is it expensive?
Pat Goss: That depends which gasket. There are many gaskets on an engine. However, the most common failure on the Neon, is the head gasket. This causes a massive oil leak often to the point the car is not drivable. The repair is several hundred dollars. But get it checked before you make a decision.
Seoul, Korea: I have a question about automatic transmissions. Is there anything we can do to prolong the longevity of the tranny besides changing the fluid at the recommended intervals? Should the "bands" be adjusted or is this old time stuff? Does changing the fluid really prolong the life? Thanks for the questions. P.S., Your tips on evaluating stalling on the t.v. show were really good. Keep up the good programs!
Pat Goss: The life of automatic transmissions can be significantly extended by flushing as opposed to the old fashioned drop the pan and change a quarter of the fluid. Although that adds some new fluid it does nothing for cleaning the transmission. A flush not only changes all the transmission fluid but it also softens and flushes away any accumulated dirt before it becomes damaging (especially in the torque converter). The flush should be performed every 2 years or 24,000 miles. On most transmissions adjustments are no longer possible. But check with your dealer.
Bethesda, Md.: What could cause an engine misfire? How expensive of a problem could it be?
Pat Goss: Unfortunately many, many things. Ignition problem, fuel delivery problem, vacuum leak, etc. etc. Usually relatively inexpensive, sometimes quite expensive. Sorry I can't help.
Washington, D.C.: Thanks for all of your helpful advice in the past. I'm in the need for more help. I have a 2004 Corolla with about 10,000 miles. I notice that when I start up the engine, the engine idles very fast (goes right up to 2000RPM) and after about 3-4 minutes it starts to slow down. I doubt that I would have noticed except for the fact that the engine is very loud. I've never noticed this with any of my other cars. Anything to worry about?
Pat Goss: Yes. Because it's under warranty get the car back to the dealer, they're looking for a possible computer programming glitch.
Brookeville, Md.: Pat,
Our 2002 Chrysler T&C was recently towed to the dealer because is would not move in any gear. The diagnosis was clogged tranny filter -- it needed a tranny service. Our van had 36,500 miles on it and the 'severe use' maintenance schedule calls for service at 48,000 miles (normal use does not list a tranny service). I am concerned about this tranny's future since it fouled the filter so quick - would you be? What would you do?
Pat Goss: I'd be very worried. Something is dramatically wrong. For there to be enough contamination in the transmission to clog the filter at 36,000 miles. That's unheard of. Actually unless something is coming apart inside the transmission or something is slipping there really isn't anything that could clog the filter that quickly. What would I do? I honestly don't know. This is so unusual I'd want a better explanation from the repair shop, and possibly an examination of the removed filter for verification.
Capitol Heights, Md.: Good morning Pat,
I have a 2002 Ford Focus that has a cassette player. I want to put a CD player in my car. Is it cheaper for me to buy the CD player and have someone put it in? Versus the dealer. Also can you tell me where I can buy a reasonable CD player? Thanks!
Pat Goss: Typically an aftermarket CD will be cheaper than a factory CD. They also usually offer more features. I'd shop at Circuit City, Tweeter, Best Buy, etc. I think you'll find a deal on a nice unit.
Michigan: Question about motor oil:
Are all of the new varieties of motor oil, i.e., one for SUVs, one for high mileage/older cars, etc., any better than conventional motor oil?
Just interested if there's any validity to the claims, or if it's just marketing. (I use Mobil 1 in all of my cars, and I don't plan on switching, by the way)
Pat Goss: As far as formulation on these specialty oils, there is no way of knowing what they are doing if anything. It's all considered proprietary. But you're using the best there is; I think you would do well to continue.
Lanham, Md.: Where can I take a 1978 Grand Prix to have it restored. The motor in it is a 1988 Trans Am. If the car is not worth restoring what other car can I use the engine in.
Pat Goss: Check with Billy Thompson at White Post Restorations in White Post Virginia. He's one of the best in the country.
Washington, D.C.: Hi, I have a 2003 Toyota Prius that I used to use for commuting 30 miles a day with about 25K miles on it. I moved, and now walk to work, driving the car about once a week for a total of about 30 miles per week. Already, in less than a month, I noticed the engine was running slightly rougher. Is there anything I need to do for it now that it's barely being used, other than regular oil changes according to the owner's manual? I may sell it in a few months.
Pat Goss: Use a fuel injector cleaner which is overdue at this point anyway. BG 44K is probably the best.
Baltimore, Md.: Pat,
What's your opinion on using long life coolants (such as Peak long life or Zerex G-05) in cars that came with the "green stuff" provided that the coolant is still changed every two to three years or 30,000 miles?
Pat Goss: Providing the long life coolant has additives that match what is required by your vehicle manufacturer. The long life product should be fine.
Springfield, Va.: Pat can you recommend a brand or vender to install a remote starting system? I could sure have used it this winter when it was cold! I have a 2004 EB Explorer and 2003 Acura TL Type S I'm interested in having one installed on.
Pat Goss: Wish I could. Don't recommend them. Therefore do not look for good places to install them. What an absolutely, absolutely horrible idea.
Arlington, Va.: Hi Pat,
I recently had a front-end brake job done on my car ('99 Lexus ES300). Although they never did before, now the brakes squeal almost every time I use them, particularly with light pressure applied. Could you give me an idea what might be causing this?
Pat Goss: There are lots of things that can cause squealing. Were the rotors machined? Was a non-directional finish applied after machining? Do the pads have the proper density for the vehicle? Were shims used? Was a silencing material applied to the backs of the pads? Was silencing material applied to the surface of the pads? Was silencing material applied to the surface of the rotors? Was new hardware installed? Were the calipers serviced using synthetic brake lube? Etc, etc. There's a lot more to doing a brake job then throwing pads into the calipers.
Washington, D.C.: My 1982 Mercedes 300D Turbo, 130K miles, began losing power last week. I stopped at an auto store and put some diesel fuel cleaner in the tank and problem solved. This also happened about a year ago.
Is this something that will happen more regularly due to the age of the car, or just some bad fuel each time?
Pat Goss: Not so much due to the age of the car. Just a lack of proper maintenance, which includes using a fuel system additive on a regular basis. Contamination builds up a little bit each mile it's driven. If no additives are used it will reach a point where it effects performance.
Herndon, Va.: I have a '99 Audi A4 and I'm putting approximately 4,000 miles a year on the car. I only use the car to drive back and forth to work (8 miles on back roads one way). Audi recommends changing the oil every 5,000 miles. Should I change the oil based on length of time between changes, instead of oil changes based on number of miles?
Pat Goss: If you value the car, you'll change it on time rather than miles. Especially because you're using the car under such severe operating conditions.
Alexandria, Va.: I took my car in for service about nine months ago. I had a timing belt replacement done (2000 Hyundai Sonata). After about 2,400 miles my car jumped time. The belt didn't break. Is this unusual?
Pat Goss: Yes, it's unusual. Often caused by a faulty belt tensioner.
Washington, D.C.: Hi Pat,
You recommended that I buy after-market
hubcaps to replace the ones stolen from
my '91 Toyota Camry. I bought some from
an Internet site for $45. Shipped. One
hubcap from the manufacturer was going to
I can't tell the difference between the
new ones and the ones I had stolen, except
that the new ones are shinier. What should
I pay to have them put on the car? Yes, I
know, but I don't do car maintenance, except
to wax the car.
In the same vein, do you think a cheap car
cover would deter thieves? I've lost 2 car
covers that cost over a hundred each, one
that was locked to the wheel axle. Would a
cheap cover help the car finish at all? By
keeping wax on the car, it actually looks
pretty good, despite its age.
Thanks for this forum.
Pat Goss: The installation should be free. Total time expanded less than five minutes. As far as the car cover goes, I don't know if it will deter thieves. That's usually not a consideration. Cheap car covers often are very damaging to paint, especially when the car is kept outdoors.
Fairfax, Va.: Yesterday a monster pothole on the American Legion Bridge took out the right front tire, rim, and hubcap of my Ford Focus. I got the tire and rim repaired at a local shop but I'm still short a hubcap. Do I just go to a Ford dealer and buy one? Do I even need a hubcap for anything other than aesthetics?
Pat Goss: The primary purpose of a wheel cover is cosmetic, although it does in some very small way help prevent rust of the lug nuts. Ford dealer you can buy one, or as in the last question; part stores have them in complete sets that often cause considerably less than one from the dealer.
Fairfax, Va.: Pat -- I have a '98 Accord with an odd noise coming from the front left wheel. When I put the brakes on it makes a sound like a rusty bedspring. The noise slows as the car slows; leading me to believe it is related to the brake pads. I have replaced the brake pads, had the rotors turned, replaced the rotors, and even had the hub bearing replaced, all to no avail. Do you have any ideas?
Pat Goss: Check the hardware and service the calipers using synthetic brake lubricant.
Washington, D.C.: Hi Mr. Goss,
My car is a 1999 model, and for some reason, the headlights on the car are extremely dim. Honestly, on rainy, foggy days, I can barely see without using the high beams if no one is around. For safety, I would like to have the headlamps changed, nothing illegal or overly powerful, just stronger for better vision. Could you recommend a brand of headlamps I could ask my mechanic about? Also, could you give me a rough idea of how expensive it would be to have this work done? Thanks very much for your advice, I really appreciate it.
Pat Goss: I use silver star lamps in my cars. Their legal but produce a more white light. However, cause your car is six years old your problem may be in the lamp assemblies themselves. The lamp material usually gets cracked and checked causing poor light diffusion. Sometimes the lenses can be buffed; the entire lamp must be replaced. Usually expensive.
Arlington, Va.: Mr. Goss,
Any general advice what else I may need to do to make sure my '91 Accord and '93 Toyota 4x4 truck keep running smoothly? Other than changing the fluids regularly (though I have been slacking on the transmission oil)
Pat Goss: Yes. Quite slacking on the transmission flushes. Other than that you're doing it.
Lanham, Md.: Pat,
I need to get my car repainted. The paint is fading & cracking. Can you give an upper & lower price range for painting a car? Would you recommend painting by the dealership or a discount painter? I want to keep the original color of the car, metallic dark cherry.
Also, when is the best time of year to get a car painted? My car is not garage kept, so I'm kinda concerned about how the elements will react with the new paint. Should I keep the car under a car cover for a while? ?
Pat Goss: Paint jobs can cost as little as $5 or 600 or as much as 50 or 60,000 dollars. However a quality paint job usually will run (for a non-show car) $2500 - $5000. Best time of the year depends on the type of paint, whether it is baked and a number of different factors. Essentially painting in cold weather frequently provides a shinier finish due to slower curing. But that's only sometimes. Whatever you do, do not put a car cover on your fresh paint.
Lexington Park, Md.: I have a '99 Chevy Malibu. The steering column makes noise whenever I turn the wheel, kind of like a person walking in corduroy pants. I haven't noticed any performance problems, but the sound is noticeable. Any ideas as to what's causing the noise and what the price is to fix? Also, I've never had the transmission fluid changed (only topped off). I have had the car for 3 years and it has nearly 60K miles on it. How expensive is it to have the tranny fluid changed, how necessary is it, and is this a dealer-only service?
Pat Goss: There are several possibilities for the steering column noise. They range from tightening a bolt to replacing some pretty expensive parts. I suggest for safety you get this checked quickly. As to the transmission flush it may be too late, depending on the condition of the fluid. If the fluid has seriously changed color. It may be ill advised to flush the transmission. If the fluid still looks reasonable the flush could cost $99 - $150.
RE: Ford Focus hubcap: I lost a hubcap once, and my husband bought a new one for really cheap at a junkyard. He used some junkyard online and they had several hubcaps for different types of cars/models.
Pat Goss: Sounds like a lot of effort. When you can buy four of them by walking in the store for $29.
Alexandria, Va.: A faulty belt tensioner? What's the likelihood of that happening? A service tech at a Hyundai repair place said the timing belt had been improperly installed and was riding the water pump pulley. I need to understand what happened to my car as my engine locked up and I have to replace it.
Pat Goss: What's the likelihood, depends on the mileage. If the car has 100,000 mileage or more, highly probable. By the way, one of the symptoms of a failing tensioner or idler pulley is misalignment of the timing belt. As to the issue of the belt being improperly installed and being out of alignment (riding the water pump pulley) that is nearly impossible. The belt rides outside its proper path because of a failure in a pulley, a sprocket, or a tensioner. I think you need a second opinion.
Chevy Chase, Md.: Pat,
When I took my flawless two year old Acura CL 6-speed in for the 40k service, they tried to tell me the transmission oil needed to be changed. The manual says it's good for 3 years or 60k. And they said, "the intake side of the engine is showing carbon buildup" and needs to be cleaned, to the tune of $150. I said no. Were either of these services were necessary or just scams?
Pat Goss: With 40,000 miles, it would be highly unlikely that your Acura didn't need some form of carbon cleaning. Transmission oil, you're right you could go another year.
Annandale, Va.: Pat I have a question for you on the need to change transmission fluid and filters in automatic transmissions. A friend who used to own a GM dealership in the 70s said he told his service manager to stop changing auto tranny fluid because it was doing more harm than good. Today, the same guy has 275,000 miles on his '82 DeVille without ever touching the tranny fluid. What gives? I always believed that automatic transmission fluid needed to be changed with filter every 30,000 miles and at least once in the life of a car to do a complete flush.
Pat Goss: Aaahhh, the good old days. Cars were forgiving. There weren't a hundred different vehicle specific-fluids. Transmissions didn't have electronic sensors, and on, and on. There is only one part of your message that is correct; changing fluid does more harm than good. There are contaminants that form in old fluid that are not necessarily soluble in new fluid. That's why changing transmission fluid is considered an obsolete service. The only service that makes sense is transmission flushing that should be done every 2 years of 24,000 miles.
Sterling, Va.: I just put new tires and had an alignment for my 2001 Pathfinder, but the steering wheel still vibrates a little bit at around 60 mph, what can be causing this? Thanks in advance.
Pat Goss: Have the tires checked for road force variation using a Hunter 9700 Road Force Balancer. Excessive road force has become a much bigger issue than balance.
RE: BG 44k: Pat,
I see that you recommend this product a fair amount. But I haven't seen it in my local large chain auto store. Where can we find it?
Pat Goss: It is not sold in stores. It is only available from repair shops to find one near you go to www.bgfindashop.com
Olney, Md.: Would you recommend the VW Toureg? I have a sedan currently, but I need something slightly bigger to haul home materials. I don't want a truck necessarily, and I love the body style of the Toureg.
Pat Goss: It's okay. Enter level tends to be better than the loaded versions, which are probably over widgeted.
Rockville, Md.: I have a 1995 Subaru Impreza with over 100,000 miles that was rear ended recently, resulting in frame damage (I can't fully close the back door). The repair estimate is $2000, and it's covered by insurance, but the car looks lousy (already banged up in a few places and the interior is not so great either). Mechanically, though, it's in good shape. I'm considering selling it for parts -- without repairing it -- and putting the cash towards something new. Thoughts?
Pat Goss: I think you're on the right track.
Pat Goss: Once more, I thank you. It's always enjoyable. Until next time, drive gently. Pat.