Wednesday, April 27, 2011

Should You Use a New Washer When Changing Your Oil?

I've recently had an inquiry about compressible washers. If you've changed your own oil, you probably know what I'm referring to: it's the washer on the shank of the drain plug of your car's oil pan. When you unscrew the drain plug, it usually remains stuck to the oil pan, and subsequently gets pried off with the edge of the open-end wrench you just used to remove the plug itself.

The particular discussion: is the washer necessary?

Yeah, I know it's a pain, but I use new washers on the drain plugs of my own vehicles. Typically, I buy ten washers at a time from the dealer's parts department. They're cheap enough, even at $1.50 a piece, which is about what they retail for. If you buy in bulk, ask the parts guy if he wouldn't mind selling them to you at the wholesale price. Usually it's about 20% off.

My personal experience with changing oil, in conjunction with what I've learned in my formal engineering education, is that it is wise to use the washers. Both my Mercedes and my Lexus use them, and there's a reason the manufacturer designed the washers into the system. As your engine heats up, metal expands. When it cools, metal contracts. When this occurs between two different parts, especially of two different materials or masses (thermal capacity and flow rate is related to mass and density), small relative motion can and does occur between the two parts. This frequently causes fasteners to loosen, even if they've been torqued to specification. Add in vibration, which is endemic to a reciprocating piston engine, and this relative motion is exacerbated. That's why the washers are there, and coated with a material that not only crushes and locks into macrosurface irregularities, but also dampens the effect of vibration and helps the fastener resist this tendency to move relative to the oil pan into which it's threaded.

I don't want to disparage anyone, but I have frequently encountered the attitude of "hell, I don't see a need for this part, so why bother putting a new one back on?" Usually, it's laziness that prompts such a reaction; it's easier to think of a reason not to do something than it is to expend the money, energy, and time to perform a task that has no clear reason to be done. Many people approach life that way, too.

From a perspective of risk assessment, the benefit of the washer far exceeds the cost. Lose the drain plug on a running engine, and that engine will be completely ruined in seconds. Then you're faced with the choice of installing a junkyard engine that's had questionable maintenance and has probably been salvaged from a crashed vehicle, or purchasing a remanufactured engine that was assembled from a bunch of aftermarket parts tossed on a table, or rebuilding your own damaged engine, if that's even possible. On a Toyota four-cylinder, the total cost of the engine and installation might run $2000 to $3000. On a Lexus or Mercedes, the cost could easily approach $5000 to $8000. And on a Ferrari 550 Maranello, a replacement engine can run from $15,000 salvaged to over $30,000 new. And remember, with the exception of a new OEM unit, the replacement engine is probably not going to be as well-maintained as the one you just burned up, because if you're reading this, and you change your own oil, you probably bought a vehicle in good condition to begin with, and you're diligent about taking care of it.

As a sidenote, an engine doesn't even have to lose its oil to be severely damaged from oil starvation. The C5 Corvette and the Generation I, II, and III Dodge Vipers could generate enough cornering acceleration to slosh the oil from the bottom of the oil pan and hold it up against the sides of the oil pan and lower engine block. This uncovered the oil pick-up, which immediately starved, and in a matter of seconds, the engine became unlubricated. The C5 engineers figured this out in testing, and designed and implemented a special cast aluminum oil pan that had internal baffles to keep the oil pick-up immersed in oil, even in hard cornering. The Viper's problem manifested itself when owners began racing their cars on tracks with long, fast, sweeping turns, and when the oil pick-up starved, if I recall correctly from my conversation with Chuck Tator, the number three bearing journal would seize. Generation IV Vipers, beginning with the 2008 model year introduced in 2007, use a swinging arm oil pickup that articulates to the right or left of the oil pan during hard cornering. This follows the oil and keeps the pick-up immersed. It's important to note that these problems only occurred during extreme performance maneuvers, and not in the normal kind of fun driving that these cars can so capably and wonderfully deliver.

Also as a sidenote, this is why certain performance cars use what's called a 'dry-sump' oil system. In a dry-sump system, there isn't a conventional oil pan hanging under the engine, filled with a gallon or two of sloshing oil; the oil is stored in a reservoir near the side of the engine, and upon start-up, there are multiple feed and scavenge pumps that force pressurized oil into the oil galleries of the engine and spray the oil into critical areas requiring lubrication. There are several advantages to this: without that deep metal oil pan under it, the entire engine can be mounted lower in the car, much closer to the ground. This results in a lower center of mass, which directly translates into better handling. Dry-sump lubrication is also immune to extreme cornering forces; the oil will be circulated where it needs to go, regardless of the forces acting on the car. It's also easier to remove heat from the oil, which is critical in extreme performance applications. Detriments? The system is more complex than a conventional oil system, which means it's more expensive to design and manufacture, and it's typically only used on high-end performance cars.

A word about filters: I haven't seen any SAE studies on types or brands, so I wouldn't endorse one particular brand over another. Personally, I'd stay away from the bottom-tier cheapest filters, but if you stay with OEM or a well-known aftermarket brand, you should be fine. There was an issue with some defective imported Italian oil filters that blew apart on some Ferrari engines several years ago, but from what I've learned, this was because the metal wall thickness of a particular batch of filters was too thin for the oil pressure that those engines were generating.

The most important factor is simply to get a new filter on at every oil change. And I'd recommend using a new washer, too.

Monday, February 22, 2010

HELP! My car won't stop!

As a crash reconstructionist with a Ph.D. in engineering, I've been asked by several people how to handle a runaway car. To my friends who drive Toyota and Lexus automobiles, and are concerned about sticking throttles:

At some point in your life, you’ll probably experience some type of accelerator malfunction. Here’s how to stay alive.

1. STAY CALM. It’s a sticking throttle, not a bomb. It’s unnerving for your car to accelerate on its own. The ‘pucker factor’ goes off the scale quickly, and I’m speaking from experience, because it’s happened to me twice. But you’re the driver, you’re an adult, and you are the only person who can fix the problem.

2. MOVE THE SHIFTER INTO NEUTRAL. Yes, it will shift into Neutral. Put your hand on the shifter. Move it one notch forward to Neutral. The engine speed (RPM) will increase to redline, but it has a limiter which will keep it from over-revving. It’ll get loud, but it doesn’t matter. It won’t explode. For cars with J-gate shifters, like the Lexus, you’ll need to move the lever to the side and then up. Don’t worry if you go too far and bang into reverse. At higher speeds, you’ll get a loud racket, but the cogs won’t engage. Don’t freak out - just move it back into Neutral.

3. PRESS THE BRAKE PEDAL FIRMLY. Don't pump the brakes- you'll overheat them, and then they won't work. If the car doesn't slow down, reach down and tug the floor mat away from the pedals. After reading Rhonda Smith's testimony, I believe this is another danger area. Make certain the space behind the brake pedal is clear.

4. MOVE TO THE SHOULDER. The car is going to start slowing down when you shift into Neutral. Your steering and brakes still work, and they have plenty of power, because the engine is still going nuts. Use the time to make it to the shoulder. Don’t veer suddenly, don’t swerve. The engine is revving madly, but you aren’t. Check traffic and use your signal.

5. SHUT THE CAR OFF. Yes, while it’s in Neutral. It’s not illegal. It won't hurt the car. With a key ignition, you won’t be able to rotate the key all the way around to remove it. Just turn it one click to the ‘accessory’ position. This will kill the engine.

6. For cars with starter buttons, you need to PRESS AND HOLD the starter button to shut off the engine. Hold it about 4 seconds in Toyota vehicles, and about 2 seconds in Nissans. In Nissans, if you hit the starter button three times in rapid succession, the computer gets the message and will kill the engine that way, too. Toyota computers just ignore this panic method. So, drill this into your mind: PRESS AND HOLD.

Remember the tragic crash in California that killed a CHP Trooper and his family? I’ve spoken with a reconstructionist familiar with the crash, and he indicated that the trooper didn’t know he had to push and hold the starter button to shut the car off. Most people don’t, and to be fair, most people aren’t going to think about this as their vehicle is accelerating like it’s possessed by an evil spirit. Remember: PRESS AND HOLD.

Pressing and holding the button will also turn the engine off while the car is still accelerating, too. And if this is what you choose to do, that’s fine. Just be aware that you lose power assist for the brakes and for the steering wheel. Be prepared for the brake pedal to become hard to press, and for the steering wheel to become hard to turn. They’ll still work, but you’ll have to use some muscle.

Also, your brakes will overpower your car’s engine. Yes, even with the engine screaming at 6000 RPM (and note, it’s RPM. Not RPM’s, or RPMs. The ‘s’ is already baked-in. Hearing or reading the term ‘RPMs’ is like stroking a cat backwards).

The caveat with using your brakes to overpower your engine is that you have to stomp them. Pound them through the floor. And you must keep them pressed until the car comes to a stop.

Do not ‘pulse’ the brake pedal. This is bad, because it overheats the brakes, and the car gains speed as soon as you release the brakes. If you overheat your brakes, they won’t stop your car. But they will absolutely overpower the engine long enough to get the car stopped. Just don’t let up until the car is stopped, even if they’re smoking. That kind of smoking isn't hazardous to your health. They’ll be okay, and they’re cheap and easy to replace. Once you’re stopped, shift into neutral (if you haven't already done so) and kill the engine. On keyed ignition vehicles, DO NOT shift into park and/or remove the key while the vehicle is still in motion. Doing so will cause the steering wheel to lock. This is generally a bad thing to induce in a moving vehicle.

As mentioned previously, I’ve had unintended acceleration happen twice. The first time was a binding accelerator linkage in a 1992 Corvette. It had been serviced by a speed shop, and they'd left the oil cap under the throttle lever. Out on the road, I opened her up. Then the cap got under the lever, and I had to change my pants. After, of course, I pushed the clutch in and got the thing stopped in neutral.

The second time was a floormat issue. The floormat issue, ironically, occurred a few years ago in a Lexus that I’d just purchased. It has an electronic throttle control similar to the ones on the recalled vehicles, although mine was not involved in the recall. The cruise was set at 70 mph, light traffic on a major highway. I shifted my feet, and the car took off.

Admittedly, the first reaction was to hit the brakes. This also shuts off the cruise control. The engine was still racing. And the traffic in front of me was coming up fast.

I hooked the toe of my shoe behind the accelerator and pulled. The car slowed down. I figured out what was going on, reached down, and pulled the mat away from the pedal.

The previous owner had installed an aftermarket set of rubber mats on top of the factory floormats. At the next exit, I dumped them in the trash.

Listen, people, floormats are replaceable. They’re available from your dealer for less than $100 in most cases. Buy a second set to use when you have company over, for God’s sake. But don’t shove a thick rubber mat up near the pedals and then wonder why it’s harder to operate the brakes and throttle. If you do need some kind of rubber trough to catch salt and snow and mud, then remove the factory mats and trim the replacements as necessary to ensure there’s no interference with the pedals.

In the case of the Toyota fiasco, I’m not convinced that Toyota even understands what’s going wrong. Shimming the accelerator pedal is a dubious fix, and sounds more like a convenient bystander that’s been charged with the crime because the real culprit can’t be found. The truth appears to be that Toyota couldn’t find the problem, so they hired Exponent, a very expensive and large forensic engineering firm, to try to find the problem. They batted zero, too.

The complexity in contemporary vehicle electronics is staggering. Repair manuals used to be a couple hundred pages of mechanical and electrical diagrams. Now there’s a dedicated manual on electrical troubleshooting that accompanies the mechanical manuals. And it’s usually a lot thicker than the mechanical book, too. Someone will probably eventually figure out that under some arcane operating condition, at just the right temperature and throttle position, the electronic throttle control gets a wide-open throttle signal. But until that happens, the best remedy for Toyota is to install software that kills the engine when the brake pedal is depressed. Nissan, BMW, Chrysler, and Volkswagen, among others, already have this incorporated into their own engine control architecture. Toyota made the decision not to use it. Which, as we see now, was a bone-headed decision that ended up killing people. Not the first time this has happened. Won't be the last.

In my line of work as a forensic reconstructionist, I’m frequently contacted by attorneys and insurance companies with requests to investigate alleged vehicle defects. Some prove valid, while many others do not.

In 2003, I testified in a court case against a major foreign manufacturer who used carbon steel screws to hold a reed valve in an exhaust gas recirculation assembly. The carbon steel screw heads would corrode, the reed valve would fall off, and 800+ F exhaust gas flowed into the air filter on top of the engine. This filter was a paper element soaked in oil that would reach ignition at 392 F. Engine fire? Absolutely. It happened to thousands of affected vehicles. More insidiously, though, was that the underhood fire generated dangerous gases such as carbon monoxide that were pulled in through the vehicle’s ventilation system at the base of the windshield. In several cases, the occupants would succumb to the gases, pass out, and then the car would run off the road and crash. The company’s strategy was to blame the engine fires on the crash instead. In most cases the crashes occurred at low speeds, because the engine would stall and the car would begin to slow down well before it left the roadway.

The evidence against the company was overwhelming. The jury agreed, and ended up awarding the plaintiff more than the original lawsuit had asked for.

The fix was simple: they should have used stainless steel screws instead of carbon steel. But for the savings of less than one cent per vehicle, they ended up killing several people and seriously injuring hundreds more.

Toyota, thankfully, doesn’t seem to be going down the same road. They’re owning up to the problem, but as I mentioned, it appears they don’t know exactly what that problem is. Rather than chase down a needle in electronic haystack, they should engineer a throttle-override that can be retrofitted to the recalled vehicles. And it could be done using software, keeping costs low. They’re already doing this with current production.

My car is still that same fancy Toyota that had the floormat problem. After two years and fifty thousand miles, it’s been the best car I’ve ever owned. And the crashworthiness of Toyota vehicles is still superior to many other manufacturers. If you want to give your Toyota away, I’ll take it. Gladly.

Cars are mechanical devices. And they’re designed by fallible humans. Mechanical devices will eventually break, and despite the best intentions, humans often fail, too. But try to make sure that you don't. If you get in a situation where the car suddenly accelerates on its own, keep your head, shift into neutral, and make it safely to the shoulder. Then change your pants.

Friday, October 31, 2008

The Real Reason for the Economic Crash: What Economists are Afraid To Tell You

Kenneth Blumberg, Ph.D., senior economic advisor at Granite Financial, went on record this week to disclose the truth behind the current economic crisis.

The problem? Exponents.

“As economists and business experts, we’ve been reluctant to admit that the underlying problem is simply about math,” Blumberg said. “Most of us have spent years in graduate school learning arcane economic theories. The post-secondary education comes after years of K-12 schooling where math and science have been underemphasized. It’s no surprise that in major business dealings, key players have neglected to punch in the correct number of zeros into their calculators.”

The issue of the correct number of zeros in a given number has become critical in recent years. While most consumers are accustomed to seeing three zeros after a single comma in their large purchases, such as the price of a $35,000 automobile or a $300,000 house, business transactions often involve multiple commas and strings of zeros that can unnerve the most savvy economist.

The central issue is that mortgage companies often overpaid for bundles of mortgages sold by lenders. For example, one thousand mortgages with an average face value of $200,000 each yields a collective worth of $200,000,000. In exponential notation, this would be expressed as…something smaller.

This number fits onto a calculator screen with two places to spare. However, when there are hundreds of these bundles being added and subtracted and multiplied and divided several times in each business day, that relatively small figure of two hundred bill…er, two hundred million grows larger than a calculator screen can display. The result is a number that is expressed in exponential notation, where the zeros behind the first one or two digits are represented as a superscript above the number ‘10’. According to experts, the number of one million expressed in exponential notation would be 106.

“The first time it happened to me, I thought I broke my calculator,” said Jennifer Taylor, a mortgage broker who was formerly with Lehman Brothers. “I saw this ten pop up on the screen with tiny numbers above it, and I thought, ‘whoa, what’s this?’”

Taylor isn’t alone. Many business people have been hit with this phenomenon.

“I went out and bought another calculator,” Edwin Smith, a securities specialist at CityGroup Financial, admitted. “And then I thought that one was broken, too. I ended up with a bunch of different calculators.” He waved an arm toward his desk, which was covered with calculators. “Every damn brand gave me the same thing.”

The resulting confusion that occurred from the exponents displaying on the calculator screen is blamed for the overpayment of bundled mortgages by major financial institutions.

“We don’t know exactly what we paid for which bundles,” Smith admitted. “My colleagues and I remembered the word ‘bundles’ being used in our cell-phone bills, so we got those out and tried to use them as examples, but it just didn’t help.

“One of the really brilliant guys at our firm finally figured out that the tiny number above the ten stood for the number of places after the first number, but it was real hard to understand. No one wanted to admit they didn’t understand it, so we all nodded and went on with business as usual. If you admit you don’t understand something in corporate America, you’re dead meat.”

This rampant misunderstanding went on for years, Blumberg explained.

“Let’s say someone gets a number that has twelve zeros after it, but it’s supposed to be eleven. The difference is ninety trillion dollars. No, wait, ninety billion dollars. I think. Pretty sure it is,” Blumberg said.

One example of a number running out of room on the display is the National Debt Clock in downtown Manhattan. The clock recently ran out of space for the digital numbers, prompting the management agency to paste a paper “$” in front of the first digital placeholder on the giant electronic billboard in New York’s Times Square.

“We’ll probably have to change it a paper “10” pretty soon,” lamented Nancy Morgan, representative of the Durst Organization that runs the billboard. “When Seymour Durst constructed the billboard in 1989, no one ever thought that the national debt would increase to ten trillion dollars.”

Ten trillion dollars is written as a “10” with twelve zeros after it. To be accurate, the twelve placeholders aren’t all zeros; the actual amount was $10,150,603,734,720 as of October 12, 2008.

Economists, though, are quick to point out that no one really cares about the numbers that follow the first comma. According to Blumberg, “the first number is the star of the show, the one that gets everyone’s attention. The second and third numbers are kind of important, but really, who cares about what comes after them? It’s like the rest of the cast on a television sitcom. Everyone knows the big stars, but the rest of them aren’t going to register.”

Others have a different view. Neil Feynman, a physicist at Oak Ridge National Laboratory in Oak Ridge, Tennessee, is one of the scientists that have been covertly contacted by the Department of the Treasury to assist in clearing up the exponent crisis.

“Blumberg’s referring to significant figures when he mentions the first three numbers,” Feynman said. “We call them SigFigs in scientific parlance. But the numbers after them are important too. I mean, come on, after the first two numbers, we’re talking about 1.5x1011.”

When pressed for exactly what that meant, he shook his head. “It’s one-point-five times ten-to-the-eleventh."

That explanation simply didn't go far enough, however.

“It means one-hundred and fifty billion dollars. See? That’s what the whole problem is. No one can understand the numbers involved here. It’s no wonder we’re in this economic mess.”

Scientists are being sought out by the Federal Government to help resolve the crisis because of their expertise in working with exponents. Physicists in particular commonly work with extremely large numbers, necessitating the use of the expression ‘ten-to-the’ in everyday matters. The problem with this approach has been the inability of physicists to communicate with economists and business leaders.

“We tried mathematicians, but they were way too abstract,” said Paul Reichman, senior advisor to Ben Bernanke. “They were always wandering off and doing math for fun. It was like herding cats. We couldn’t get an applicable answer out of any of them.”

Physicists, Reichman said, are better suited to delivering answers that can be actually applied in the real world, but the challenge is identifying physicists who can interact intelligibly with laypersons in the economic setting. Reichman is quick to point out that he’s not referring to foreign language barriers.

“The language isn’t the problem, it’s understanding each other. We can’t get them to understand what we need, and they can’t understand why we need it.” Reichman rubbed his forehead. “It’s the most frustrating thing in the world to talk to someone in plain English, thinking that they’re getting it, and then they turn around and deliver something completely different.”

Compounding this problem is the sudden dearth of physicists willing to travel to Washington, D.C. and interact with the people who need assistance. “They’re all over in Europe trying to fix that collider thingie,” Reichman said.

The Fed isn’t giving up hope, however. Reichman told reporters that help from the Chinese government is also on the table.

“The Chinese are in a very vulnerable position. They own most of our debt, so they don’t want us to become insolvent. But they also need to keep their manufacturing base intact. Without easy loans, the American consumer can’t refinance their homes to buy cheap plastic crap. Chinese companies that make inflatable Christmas lawn decorations are being particularly hard-hit by this crisis.”

“We’ve discussed the problems that economists and business people have with adding and subtracting large numbers, and not understanding how to use exponents, and the Chinese have already initiated the design and manufacture of special calculators that have extra-large displays. Theses calculators will be able to go up to big numbers, you know, like ten gazillion, without using exponents. Just one long number. And they’re putting commas in the display,too.”

Reichman was questioned by one reporter who had made it to the junior level in a mechanical engineering curriculum before switching to journalism about the use of the term ‘gazillion’.

“It is a real number,” Reichman asserted. “That’s why you’re a journalist and I’m an economist. And the Chinese calculators are going to have separate buttons for million, billion, trillion, quadrillion, and gazillion. The individual buttons should eliminate the need for people to understand exponents. It will take time, but we will turn the corner, and the economy will be stronger in the long run.”