Category Archives: Shop Talk

An oil and filter change every 3000 miles = money down the toilet

This says it pretty well. An elevator arrives no sooner because you push the button repeatedly with all the strength in your body. Add 2000 miles to that “next service due” on your lube sticker, or much better yet, used the computerized reminder indicator on your dash if so equipped. Be advised, these reminders frequently fail to get reset at your drive-through lube facility so will often come up prematurely.

Remind me to address “tune-ups” before too long — a term that should be considered obsolete for the modern automobile.

The engine oil dipstick is NOT obsolete!

Please! Every year Don’s Automotive sends a few cars off to the salvage yard that could have been saved by pulling a quart of oil out of the trunk. These days, you ask somebody when they last checked their oil and most people will tell you when they last changed it — probably way more often than serves a purpose. See above. Even if never a drop of oil leaks to the ground, some oil is burnt and goes out the tailpipe, rendered invisible if the catalytic converter can keep up with its task of afterburning. Oil should be checked on a brand new car, but put 100,000 miles on the engine and it becomes that much more critical. If there was no such thing as routine oil consumption the dipstick could be eliminated and a service technician would simply consult a sticker or manual for a refill specification when performing an oil change.

How often should engine oil be checked? Brand new car, maybe every 2000 miles. High mileage or any suspicion of a leak, maybe every other tank of fuel. Please remember, a glowing red “oil” light means “rapid engine destruction in progress.” Tires and radiator also, please.

It’s hot, its tempting, but PLEASE don’t do this!

I refer to trying to recharge your AC yourself without having adequate equipment to analyze the system’s condition. The gauge on the kit from Autozone or Pep Boys does not measure both sides of the system. It is very easy to overcharge the system with potential damage. Also, even the low side gauge readings are variable for a given level of charge depending on the condition of the compressor and the expansion valve. The proper way is to pull the refrigerant into a recycling machine where it is weighed and the service technician knows how much — if at all — it fell short and how much to add to bring the level to factory specs. This service should include adding a leak detection dye if none is already present and examining the system under ultraviolet light for the presence of leaks. At Don’s the price of $107.50 plus refrigerant and dye includes a free follow-up inspection, while you wait, in a week or two.

Much worse is using refrigerant with “sealer” added. This substance destroys AC systems and destroys professional service equipment.

More misinformation from Click & Clack

I don’t listen to their radio show because it annoys me how much they laugh at their own tired jokes. But today I read their column in the Statesman. The first topic they answered well, the second, not too well at all. It concerned someone who drove a ’98 Toyota Corolla on bad roads and experienced steering wheel shimmy at 60-70 mph despite having had the car’s wheels “balanced and aligned.” Click and Clack offered two possible explanations:

1. Tread separation on a front tire.

2. A loose tie rod end or ball joint in the front suspension.

Tread separation would have been caught by a proper wheel balance job. A loose tie rod end or ball joint has the following symptoms: Clunking and knocking at low speeds when turning or going over bumps. If a tie rod end or ball joint is catastrophically loose, a wicked “death wobble” vibration will be triggered when you go over a bump at about 30 mph or less. This vibration is such that you will pull over to the side of the road wishing you had a change of underwear with you.. High speed shimmy is not generally a symptom of a loose tie rod end or ball joint.

The following are common explanations for high speed steering wheel shimmy:

1. A wheel balance operation was not successful due to poor equipment, poorly maintained equipment or operator error — happens all the time. My 3/4 ton crew cab diesel truck has wheels too big to fit our shop’s balancer. NTB flat out cannot balance my truck’s wheels — after they tried several times I got disgusted and tore off all the weights they had put on and it shimmied far less! Recently, Discount Tire was finally successful on about the sixth try. This was with new Michelins and me standing over them telling them how to do it and insisting they use different equipment than what they had tried without success on two sets of new tires. And, that said, Discount Tire is one of the best of the “big box” tire chains.

2. Front tire out of round or rim grossly bent so the wheel/tire assembly is technically balanced but does not roll true.

3. Shimmies when brakes are applied at highway speed because of brake rotors that are not flat and of uniform thickness due to warpage from the repeated heat generated by braking. Probably 50% of vehicles on the highway have this syndrome to a greater or lesser degree.

4. Inner CV (constant velocity) joints on the front wheel drive axles can cause a wicked vibration up the steering wheel any time the gas pedal is applied at high speed and they are under torque. This is, in fact, particularly common with the drive axles used on certain Toyota Corollas and Geo Prisms.

All four of the above are commonplace, but Click and Clack only mentioned #2, (sort of).

If you think they are entertaining, that is a matter of personal taste. If you think their information is to be trusted, I regret to inform you it is not.

Heat wave brings out unscrupulous opportunists

Seasonal snake oil … If this product actually kept refrigerant oil from clinging to the walls of the components in the AC system, the compressor would promptly seize up causing repairs in the $1000 + range. Most likely, it simply does nothing. When it gets hot the snake oil salesmen hawk magic AC system additives, when gas prices surge they hawk all manner of gadgets and substances claiming to improve mileage, reduce emissions and increase horsepower all at once. Of course, health issues are such an intrinsic part of our existence that they are responsible for the lion’s share of snake oil marketing. My personal trainer has heard it all regards ways to drop 100 pounds of fat and gain 50 pounds of muscle in no time and with minimal work. None of it works, but wishful thinking and gullibility are universal human traits. I know better re’ automotive products with extravagant and implausible claims, but I am sure I have been duped in other areas at various times in my life. It is pretty pathetic how often advertisements for a scam product are presented as news.

“I already had it checked out, but they want way too much. How much would you charge?”

If I never hear this again it will be to soon for me. With rare exceptions, the premise this question is based on is intrinsically flawed. Is the other shop trustworthy or not? If the other shop is trustworthy then just let them fix what they have already inspected, diagnosed, confirmed by testing etc. An old cliche’ about switching horses in mid-stream comes to mind. If they are NOT trustworthy, then their repair recommendations beg a second opinion far more than their prices. In fact, when money is spent on car repair with poor or no value received, an excessively high price for a well-advised choice of repair procedure is almost never what happened. In the overwhelming majority of cases, poor value is received because A: The suggested remedy did not address the problem, or B: Unnecessary repairs were sold.

This question is also highly insulting to the repair facility who essentially is told, “I went to the high-dollar experts to find out what needs to be done, now can you do it cheap?” When dealing with independent business people, I find I receive the best value in the long term by being respectful.

Gas prices going up, why should you pay even more for higher octane?

Let’s start by understanding what octane means, and what it doesn’t mean. It is not a rating of fuel system cleaning ability. Gasoline has detergents. This renders fuel injector “flushing” as a maintenance item almost always pointless, but that will be another topic. Octane ratings do not define the quality or amount of detergent additives. Most everyone has heard of the practice of occasionally running a tank of premium in a car to “clean it out.” This serves no purpose. Octane ratings do not define the energy load in a gallon of gasoline. There is no automatic correlation between increased octane and increased power. So what does octane mean? It has been taught that the gasoline engine produces power by gasoline/air mixture explosions. This is not strictly correct. The burning should not be a violent explosion, but instead a very rapid flame front should travel across the combustion chamber. But under certain conditions, before the flame front has completed, all of the remaining fuel/air mixture will spontaneously explode. This hammers the piston top and the phenomenon is known as “pinging” due to the noise it makes. Pinging reduces efficiency, and, in excess, is damaging to a gasoline engine. This is more or less how a diesel engine always burns, and why diesel engines are so noisy. It is also why they are built with much more massive and rugged pistons, rods, crankshaft, block etc. than used in gasoline engines.

Whether or not an engine pings depends on:

A: Combustion chamber temperature. Higher temperature means more tendency to ping.

B: Incoming air temperature. Higher temperature means more tendency to ping. Hence pinging is more prevalent in hot weather.

C: Ignition timing. The earlier in the cycle the fuel is ignited, the greater the peak pressure developed and the more tendency to ping.

D: Density of the air/fuel mixture. The greater the throttle application, the more tendency to ping. You might hear your engine rattle and ping going up a hill, but not idling or coasting downhill.

E: Compression ratio. The higher the compression ratio, the greater the mixture density and hence tendency for the engine to ping.

F: And…OCTANE RATING OF THE FUEL. The higher the octane, the more the molecular structure of the fuel is RESISTANT to pinging. That is what octane means and all that it means — the fuel’s resistance to burning in a violently explosive mode.

So, traditional informed wisdom has been that one should use the lowest octane where little or no pinging is heard. Possibly lower in the winter than in the summer, possibly lower for getting groceries than for towing your boat. Modern computerized engine controls make this not so simple. For the sake of maximum efficiency — that is to say maximum fuel mileage and horsepower, minimum emissions — the compression ratio and ignition timing of a modern engine are pushed close to the point of producing ping. The modern engine has a “knock sensor.” This is a microphone on the engine tuned to “hear” pinging. If pinging occurs, it sends a signal to the engine computer that says “Whoa Nellie….back of the ignition timing!” Pinging is controlled, but fuel mileage and power suffer with the less efficient timing setting.

So my advice is consult the owner’s manual. You rarely need more than the recommended minimum octane rating. If the owner’s manual for your car calls for higher than 87 octane, but the weather is cool or you drive gently, try using a fuel with less than the recommended octane. If fuel mileage doesn’t suffer and it doesn’t rattle and ping going up a hill, save yourself some money. Buy the octane rating you need and no more. Gasoline is expensive enough without spending extra to no purpose.

Ha!! I thought so — NASA and NHTSA find NO evidence of electronically induced runaway acceleration in any Toyota

See this article. Yes, Toyota had a problem with floor mats that were too thick and a dubious gas pedal in certain cars. But what happened after that was media-induced hysteria with help from some obvious publicity hounds and people looking for a scapegoat for their own driving errors. It became the Audi 5000 phenomenon all over again — but even more out of control due to the power of the internet. Brakes are stronger than engines and a car won’t runaway if you take it out of gear or turn off the engine — end of story.

Our cars and trucks are fixing to lose a little more gas mileage thanks to ethanol

Corn-based ethanol is a huge boondoggle. It is hard to transport, needs lots of petrochemicals to make and is a net environmental loss. Unfortunately, all of Washington is terrified of offending mid-west corn farmers who are accustomed to huge subsidies. There was a recent announcement that ethanol polluting your gasoline is going from 10% up to 15%. A gallon of ethanol contains substantially less energy than a gallon of gasoline. Expect slightly decreased mileage, possible increased hot weather vapor lock problems, more “check engine” lights, and absolutely NO benefit except for some a misguided perception that ethanol in your tank serves a “save the planet” purpose.

Get with it, Click & Clack!

I am not a great fan of these guys because I find it annoying how much they laugh at their own “jokes.” But, apart from that, as much as they are rolling in the $$$, why can’t they hire someone to check their facts? In a recent column they discussed a car with a broken timing belt. On many engines, if a timing belt breaks the pistons and valves crash because they are trying to occupy common space with things out of sync. This bends valves at great expense.

Click & Clack stated that bent valves can only be verified by teardown or by replacing the belt and seeing what happens. By merely removing the valve cover, we at Don’s Automotive have many, many times verified bent valves. It is easy to see if any valves are stuck down. This requires minimal time and NO purchase of parts. If this is what they mean by “taking it apart” they should have discussed this option.

Click & Clack stated that if valves are bent a new engine is required!! That’s news to us here at Don’s Automotive — and many other shops I am sure — who have removed the cylinder head from many a “crashed” engine, sent it to a good machine job to be repaired as needed, and reinstalled it with absolutely NO repercussions down the road.

Click & Clack alluded to a slim chance of extreme good fortune where the belt breaks with the camshaft in a position such that all the valves are half-way open. No such position exists! At any position of the camshaft(s) some valves are closed, some are open and some are in between.

If you enjoy hearing people laugh at their own jokes, listen to Car-Talk. If you want accurate information about matters automotive, look elsewhere.