Auto Service World
Feature   July 1, 2004   by Auto Service World

New Tune-Ups, Old Vehicles

OBD II Ain't New Anymore

Talk about the latest technology all you want, wax eloquent about fuel cells and hydrogen power, the reality is that the cars on the road today are the ones that landed there nearly a decade ago. Recognize that OBD II ain’t new anymore.

When it debuted in 1996, On Board Diagnostics II was supposed to keep emissions in check and put an end to cars failing without the knowledge of the owner. It has not exactly achieved that goal, but the control systems that accompanied it to keep emissions in line have meant that even some pretty major deficiencies have been covered up, sometimes for years.

So, when an eight-year-old car enters an independent garage for underhood service, it may be doing so for the very first time.

“The fleet is aging and vehicles are getting older and they are getting more miles on them,” says Rob Tribe, national sales manager for NGK Spark Plugs of Canada Ltd. It may not always be immediately realized, but that aging vehicle fleet has its roots firmly planted in technologies with which, in some cases, the aftermarket still struggles to cope. Tribe says the spark plug mix, for example, has moved firmly into the platinum growth mode. In most urban centres there has been a good acceptance of replacing these platinum and iridium-type plugs with the same technologies, though in some outlying areas there is still the occasional tendency to look for less expensive alternatives.

One sometimes overlooked factor is that vehicles in a service bay for their first spark plug change are probably ready for a new set of wires and other components.

“Wire sets do get old, they do get porous and they do crack,” says Tribe. The use of coil-on-plug technology, or slave coils, has created a significant change in the wire set volume, but that doesn’t mean dollar volume has declined.

“The domestic big three are primarily using wires, with the exception of Daimler Chrysler. When you look at a GM slave coil application, if they have three coils they are charging twice what they charged for eight wires.”

Unit demand may be flat as a result, but the dollar volume is growing in the double digits.

The knack is to capture that business.

“With the higher-mileage vehicle, I would say that the majority of the folks we come into contact with really do emphasize a lot of the system degradation,” says Doug Vidler, North American service manager, Delphi Product & Service Solutions.

He says that the continual OE message of long maintenance intervals means that some cars have barely had their hoods lifted before multiple system failures land them in the service bay.

Service opportunities left undone can build up. “Typical things like fuel filters and air filters, things like fuel injection decarbonization and making sure that all the normal things are good and tight. Even an oil leak in a car can cause unauthorized air to get into the combustion chamber.

“The computer can cover up to these types of problems, but only to a point.”

Imagine a triangle, says Vidler, balancing emissions, fuel economy and performance.

“When the computer has to compensate it is at the expense of the other two to maintain emissions. If your fuel economy starts going down, if performance starts to go down, and there is enough room to compensate, it might be a good long while before this shows itself,” says Vidler.

“One trend that we are finding alarming is that people are just leaving wires on way too long,” says Brent Berman, ignition product manager, Champion Spark Plug, Federal-Mogul Corporation. “The more they buy into the 100,000-mile myth [we] find that subconsciously technicians are too,” he adds.

Yet some old habits die hard, he says.

“Traditionally, the first tune-up is plugs and oil change and an air filter. What we’re seeing is that there is still that mentality–even though there are 80,000 miles on the odometer and it is something we used to do at 12, 000 miles.”

The result is that good plugs are going on bad wires, and worse.

“The thermal cycling that goes on over the course of 130,000 km just bakes the wires. The silicone all dries out and the insulation breaks down,” says Berman. “We are seeing many spark plug returns because the boot didn’t seal properly. The heat causes the boot to take a thermal set. It is fine with the original plug, but the old wire on a new plug does not get a good seal.

“We see a lot of plug claims where the guy thinks that the insulator is cracked and it ended up that it just didn’t get a good seal.”

He says that years ago, there was a move in the industry to have people replace wires when they replaced plugs. “That’s true now, and maybe even before with some plugs.” The situation has progressed to the point where Berman says the company is producing a booklet on how to read a plug wire, now viewed as being at least as important as being able to read a spark plug.

This certainly could be the case, as suggested intervals of 160,000 km between plug changes continue to take hold of the vehicle fleet at large. After all, a plug with 100,000 km on it could still have a third of its life left, while the wires that are subjected to the heat and contamination of the engine bay might be severely compromised by that time.

According to Honeywell, which manufactures the Autolite Professional Series Wires, if neglected, grease and oil build-up, combined with high under-hood temperatures, will cause the wires to age prematurely. Road salt and conductive dust start to ground the electro-magnetic field that exists around all wires. This aging can eventually lead to the electrical leakage that causes misfires.

The company advises technicians and DIYers to check to see if boots are brittle or cracked, and if there is corrosion on the connector inside boot. If any of these conditions is found, says the company, the wires should be replaced.

Ram Vattompadam, president of Nu-Autowire, says that a good quality wire should last in the region of 100,000 km easily, but its life can be much shorter. “The engine compartment has to be kept clean. If people drive through muddy, dusty, oily areas, they can get brittle, and with a muddy coating they don’t last too long. It could be anywhere inside of two to three years and your wires are gone.”

Water he says, is the real culprit, because it can get into every nook and cranny and begin the corrosion process, where intermittent misfires start.

Similar creeping failures are present in the sensor world, too. Oxygen sensors have become much more sophisticated over the years, but earlier designs are still quite prevalent on the road.

More than 90% of vehicles currently on the road are equipped with oxygen sensors, according to the Robert Bosch company, but nearly half were built before OBD II technology came onstream.

“These are equipped with one or two unheated thimble-type O2 sensors or heated thimble-type O2 sensors, mounted upstream from the catalytic converter,” says Norihisa Akamatsu, Group Product Manager – Engine Management Products for Robert Bosch Corporation. While there are more later model sensors on the road, the replacement market is currently tipped in favour of the older sensors, though this will surely change over time, according to the company.

“Oxygen sensors produce a voltage signal that switches almost instantaneously from low voltage to high voltage as the air/fuel mixture changes from lean (too much oxygen) to rich (too little oxygen) and vice versa. Oxygen sensors can become sluggish and less sensitive as they age, and a worn O2 sensor is often the main cause of failure to pass an emissions test,” says Akamatsu.

These “lazy” sensors may go unnoticed for years, stealing fuel mileage and performance while slowly killing a catalytic converter.

There are many other such situations that can affect the performance and longevity of a car. Fuel injectors can become the victim of deposits, leading to poor start-up performance for example, and carbon can build up on the intake valves, making performance erratic and anaemic. One of the biggest problems in getting the message of system degradation across is that the underhood
environment may appear downright sanitary.

“Twenty years ago, a car with 130,000 km would have oil leaks, blow by, and typically it looked like, well, it had 130,000 km on it. You can look under the hood of one today and it looks like new.”

And perhaps this is the biggest barrier to overcome. To be truly effective, technicians need to rely on their eyes and ears, not just diagnostic tools. They need to look for corroded connections, deteriorating wires, and be aware of fuel pumps that are slowly dying, all in the interest of keeping a car running properly, and a customer happy.