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Import Car service in Springfield, MA.

Technician tenacity

Today’s technicians today have to be patient, tenacious and smart in order to diagnose many problems on today’s cars ….

This one is a good example. A client brought us her 2006 Audi A6 Quattro. She said the check engine light was on and car seemed to run a little sluggish.

Master technician Bob Toti began by attaching our VAG tester (the special Audi test tool) to the vehicle’s diagnostic port to read any stored faults. The tester showed two current faults: a cam sensor bank on 2 fault and a small evaporative leak. He also found an intermittent or old low pressure fuel sensor fault.

Whenever you find “current” faults you can verify them by clearing them and seeing how they reset themselves. That’s what we did in this case. Bob found the cam sensor fault came back immediately so he focused on that problem first. After verifying that the voltages at the sensor were okay and wiring from engine module was okay too, he swapped with the identical sensor from bank 1. The result? The same fault occurred. At this point the tech verified that the engine module was reading information from that sensor, but was this information correct?

Master technician Danny Ferrari now took over solving the Audi cam sensor fault mystery while Bob concentrated on other work in the shop.

Using actual values in the VAG, the tech found the intake cam in bank 2 was out of position by almost 10 degrees, when the spec was less than half a degree.

Careful and thoughtful technicians found that this little
bit of screen stuck in the valve was giving the customer
big headaches.  

This car’s cam advance system is able to advance or retard all the 4 cams by letting oil in and out of four solenoid valves. For some reason one of these cams was working at the wrong advance angle, or at least that’s what the sensor was telling us. The next step was checking the actual cam advance valve by opening up the engine and comparing the observed position of the cam with the position reported by the sensor. That check showed the sensor to be telling the truth – the cam was really out of position. But the question of why that might be remained unanswered. So we removed the adjusting solenoid. When we took it apart we found debris tucked into the valve, between the sleeve and the moving part of the valve. The debris looked like really small bits of metal screen. The debris was causing the position problem by not letting the valve close all the way.

Replacing the valve fixed the problem. A long road test after repair did not reveal any other faults. The other codes – the ones we’d read on first examination – never returned. We changed the oil and sent the car down the road with a very happy owner.

Why would this valve go bad on a 28,000 mile car? I wish I knew. There was no evidence of neglect or abuse inside the motor, though some of the stresses that might have led to this failure would not leave a visible trace. It’s also possible the car was filled with the wrong oil earlier in its life. Perhaps the valve was defective from new. It’s a one-of-a-kind problem in this shop. And more and more, that’s what we see. One-off problems other people can’t fix are becoming our stock in trade.

Rattles in late model Land Rovers

Does your Sport or LR3 sound like the spare tire is loose under the vehicle?  Have you looked and looked but found nothing loose?  If so, there's a good chance your problem is a worn sway bar.

What is a sway bar, you ask?  I'll tell you . . .

A sway is a torsion bar connecting the left and right sides of your suspension together.  The bar simply swings up and down when both wheels move together.  When one wheel goes up, as when it hits a curb or pothole, the bar resists that movement, adding to the spring rate.  When one wheel goes up and the other goes down, which is what happens when the vehicle leans into a corner, the sway bar resists doubly as its ends are twisted in opposite directions.

Sway bars are what keep your car flat when it makes a hard corner.  Without them, the body would lean on the springs to the point where you felt you were about to turn over.  Anyone who drove an old 1980s Rover without sway bars will remember this feeling well.

The Sport is a pretty high performance rig, so it has particularly beefy bars.  And of course these are heavy vehicles.  To handle all that the bars on my 2006 truck are almost an inch in diameter.  When they twist against the mounts during cornering, they twist hard.

For many years we have seen sway bar links wear out; not just on Land Rover but on BMW, Mercedes, and most other high performance cars.  The links are the rods with ball-and-socket joints that connect the sway bars to the suspension, out by the wheels.  We're accustomed to finding those worn out and rattly, but when these newer style Rovers began coming in with heavy clunks those links were surprisingly tight.  What gives?

It turns out that the bars themselves get loose in the mounts.  When they get loose, they rattle. At first we thought there was an easy fix - install new bushings.  However, the bars themselves are wearing down from friction with the bushings, so new rubber just fixes the problem for a month or so, and you have a comeback.

We have actually cured some trucks (including my own) by making sheet plastic sleeves that we fit between bar and bushing.  You're probably imagining something pretty high tech, but actually, we cut a strip out of an old windshield washer solvent bottle and wrap that around the bar.  Cheap and effective.  If you don't like that, or it does not work, your next step is to replace the bars themselves but that is a several-hour task involving lifting the truck body from the subframe to get the bars in and out.

Once you've heard a few of these noisy bars you learn to recognize the sound, and repair is pretty quick.. But we struggled many hours to find this one the first time . . .

Exceptional or Ordinary? You decide . . .

How do you solve math problems in your head? Perhaps a better question is, do you solve math problems in your head? With the availability of electronic devices to do it for us, I would not be surprised to learn that many people never try.

I was reading Darold Treffert’s book on savants, and I was intrigued by a few examples of savant thinking. I tried solving some of the problems in his book to get a feel for how “comprehensible” they might be to me, with no recent practice calculating. Here is a simple example:

You have a carriage with a wheel that’s six yards in circumference.How many revolutions will the wheel make while traveling two hundred twenty miles?

This is how I answer that question in my head. I’d be interested in how you might do it:

Six yards is eighteen feet. I see that as a short line.

So one hundred revolutions of a six yard wheel would take me 1,800 feet. That’s a much longer line in my head, one that curves.

Three hundred revolutions would take me 5,400 feet – more than a mile. Now the line has curved back unto itself, making a circle.

How many rotations are there to a mile? Less than three hundred. A mile is a smaller circle. I can see those circles, on inside the other.They do not quite match.

I adjust the length of the longer line that forms the big circle. Try 290 . . . that’s 5,400 less 180, or 5,220. A mile is 5,280. Now I see the line laid flat, like a straight stretch of highway. Two hundred ninety revolutions leaves us sixty feet short of a mile marker. So what’s the fraction?

Three eighteens go into that sixty-foot remainder with the same six remainder. Adding that to the 290, I see the answer is 293 and a third. The six-yard wheel does not fit a one mile line, but it fits perfectly into a three-mile ring. If you put a mark on the wagon wheel, and mark any point where it touches the big circle, those points will touch every time the wheel rolls past. I like that.

If you roll the same wheel around a one-mile ring the points will only touch every third trip around, which is unsettling to me. I like smooth fits, so I will solve the next step using three-mile units.

I can now see the answer: 880 revolutions. A perfect fit. Six yards, three miles, and eight hundred eighty turns.

How many three-mile eight-hundred-eighty revolution units are there in 220 miles? My mind visualizes stacks or piles for this next step.Seventy units reach two hundred ten miles. I quickly see how seventy-three and a third are needed to reach the two-twenty goal.

Stacking seventy-three piles of 880 in my mind takes a little time.Eventually, the stacks add up and I see the result is 64,240. Now I just have to add the third (of 880) and I’m done. To do that, I add three hundred to the pile, making 64,540, and then take back six and two-thirds.

64,533 and 1/3 is the answer to the question.

As a further experiment, I scaled up the distance, to 2450 miles and then 20,315 miles to see if I could keep scaling up the numbers. There must be some limit to that, and it certainly took me longer, but I solved those bigger problems in a few more minutes. Solving the longer distance problems involved one and then two more levels of “stacking” in my mind.

It does not seem that hard to me. I often did similar calculations as a kid, for fun. I’m sure I could do it again, pretty quickly, with some practice.

I test my answer with a calculator. The process to do that is considerably simpler.

I multiply 220 (miles) by 5,280 (feet per mile) to get 1,161,600 – the total distance in feet.

I divide that by 18 (the wheel circumference) to get 64,533.333 – the revolutions turned.

It’s a lot faster to get this answer with a calculator, for sure. But is the ability to figure this out in one’s head really exceptional? In today’s world, I would not be surprised if kids never develop these skills. When I grew up, though, pocket calculators did not yet exist and I had to know how solve problems like this. I suspect many people of my generation could solve a problem like this in their heads, but perhaps I am wrong. What do you say?

Some thoughts on spark plugs

Advances in technology have lengthened the maintenance intervals for many pieces on our cars. One of those pieces – the one I am writing about today – is the spark plug. All gas engine cars have them.

When I started in the car business, it was common for plugs to need cleaning every year, and replacement by 15,000 miles. As technology improved and engines got cleaner, the plugs started lasting longer. First it was 30,000 miles, then 50,000, 60,000 miles.

Today, many of the new cars we service have 100,000-mile spark plugs installed at the factory. That 100,000-mile rating was derived by installing the plugs in test vehicles, and then driving them hard and fast to pile on the miles. At various intervals the plugs were removed and inspected for wear. After a number of engineering tweaks, Bosch, Beru, NGK, and other spark plug manufacturers came up with a plug that would last the 100,000 miles and still perform acceptably. Based on that, the carmakers established the current change interval for spark plugs.

So the question today is: How often should you change your plugs, if you have a car with the 100,000-mile change interval? Should you follow the manufacturer’s recommendation, or do something else? Why?

The first thing I point out to new clients when we discuss maintenance is that there is a time component to service as well. Spark plugs may hold up fine for 100,000 miles if driven on the highway every day, but short trips and occasional use will wear them out a lot faster. A person who drives 10-12,000 miles per year may not hit 100,000 miles for almost ten years. That’s way to long to leave a set of plugs in the car.

Carmakers recognize that. If you look in most owners manuals you will see a time specification for plugs. They’ll say something like five years or 100,000 miles. I strongly suggest you pay attention to this time limit when considering long-life wear items like spark plugs.

I have read of spark plugs breaking off in the cylinder head when removed after many years. I’ve never experienced that on a five year old car, but there may well be parts of the world where corrosion is worse (near the ocean, as an example) and it you live in such a place, you’d be wise to consider that fact and adjust your service intervals accordingly.

When changing plugs, the next decision a motorist faces is what plug to buy. If you are at the dealer, the decision is simple: you’ll get original equipment plugs. If you’re at a Bosch Car Care Center, you should get the correct Bosch plugs, and if you’re at an independent or chain store, you best find out what they propose to install to be sure you are comfortable.

Thirty years ago, selection of spark plugs was simple. A dozen part numbers would service a majority of the cars on the road. Today many cars have special plugs and it’s important to install the right one. Every parts store has cross-reference catalogs, all of which lead you to believe any “crossover” plug will work. In my experience, that’s often true for older cars but often wrong on newer vehicles. We’ve seen Land Rover, Mercedes, and BMW cars with ignition misfires that were ultimately traced to “supposedly correct” but off-brand spark plugs.

If you have a late model car, be sure you fit the right plugs.

The last point I’d like to address with spark plugs is what happens if you don’t change them in time. As plugs age, the voltage to fire them increases. A plug that needs 20,000 volts to fire when new may need 80,000 by the time it’s used up. If you go beyond that, the voltage may rise to 100,000 volts or higher. This increased voltage puts much greater stress on ignition coils and wires. Premature ignition failure is the usual result of running plugs too long.

Six spark plugs might cost $80 for your BMW or Mercedes. Six spark plugs and six coils (because you waited too long) could cost $700, maybe more. As you can see, changing plugs before the ignition fails makes very good economic sense!

Electronic Module failures

We are seeing a disturbing trend with many high end cars built in the 1980s and 1990s. Their auxiliary control modules are failing, and replacement parts are not available. You can still buy engine control modules for Jaguar, Land Rover, and Rolls Royce cars, but many of the other electronics have been discontinued.

We can fix some issues on these controllers, but one thing we can't fix is extensive corrosion damage from failure of the "permanent" backup batteries many of these modules carry inside.

If you have a collectible European car, and it's 12-15 years old, it's time to pull the modules apart and address this issue BEFORE you have irreparable damage. As much as it may cost to fix something that's not broke, it will cost way more once it is broke . . .

Supercharged Sports that suddenly stop charging

A few weeks ago, I had a strange and curious experience with a Range Rover. It started with a simple warning light, and the usual request. “Can you reset my check engine light so I can get a sticker?”

Why do so many people think these lights come on just so they can be reset?

What possible purpose would that serve?

I explained that we’d have see what fault codes were stored, at which time we could decide what to do about them. In most cases, when you see a check engine light, you need a repair, not a reset. Codes mean many different things. Sometimes, they point to specific repairs. For example, a “replace Thelman wire” code is self-explanatory. You replace the Thelman wire. Other times, codes are more vague. “Fuel mixture out of range” can mean most anything, from air leaks to snoot problems.

This particular car had a code for inoperative cam adjusters, which was strange, because Supercharged Sports don’t have cam adjusters at all. We cleared it, and it came back right away. We looked closer at the engine, to make sure it had not grown cam adjusters on its own. It hadn’t.

Every now and then, mechanics run into situations like these . . . codes that don’t make any sense at all, yet will not go away. When that happens here, we look to see if a software update will fix the car. We use our test system to get the software version and we compare that to the latest version Land Rover lists for that particular vehicle. If there’s newer software, we install it. When we tried that, we found something even stranger.

The vehicle had software for a non-supercharged Sport installed, and the computer was telling us it had never been re-programmed. Either the car had been running around for four years with wrong software, or the computer was lying. Which was it?

After some interrogation of the motorist associated with this particular vehicle, we concluded that the software was probably original. How they made it through four years of operation, only complaining about a check engine lamp now, remained a mystery.

We downloaded new and correct software, and the problem vanished. The cam adjuster faults disappeared, and all tests were normal. We felt great pride in a job well done, and handed the vehicle back to its owner. Unfortunately, this particular Sport did not stay fixed.

“My car was in the passing lane, doing 70, when it lost all power and the check engine light came on. I coasted to a stop, shut it off, and started it again, and it was normal. That’s happened every time I drive to New Haven, and I’m getting scared to take my truck on the highway. What’s up?”

Did the car have an aversion to New Haven? I’ve seen such things before. “Bring it in,” I said, and we’ll see what the codes tell us. A check revealed a P2601 code, which points to a failure of the pump that moves water through the supercharger when you get on the throttle. His seemed to be failing. But why now?

A check of Land Rover service bulletins held the answer:

Land Rover Technical Service Bulletin #LTB00041, Rev 2

Reduced Power Under Load

Possible DTC P0096 and/or P2601 Stored

AFFECTED VEHICLE RANGE:

Range Rover (LM) Supercharged 6A198058 to 7A261419

Range Rover Sport (LS) Supercharged 6A901924 to 7A109767

CONDITION SUMMARY:

REDUCED POWER OR MISFIRE AT HIGH ENGINE LOADS

Situation: The customer may complain of reduced power and or a misfire at high engine loads and road speeds, with the possibility of Diagnostic Trouble Codes (DTC) P0096 and/or P2601 stored. The electrical harness power supply and ground for the auxiliary coolant pump may be cross connected in connector C3006. The pump will run backwards causing the Engine Control Module (ECM) to reduce power to prevent damage because the pump flow is low. The auxiliary coolant pump will be degraded under these conditions.

Action: Should a customer express concern, modify the wiring at connector C3006 to the correct positions and install a new supercharger coolant pump as part of the repair if either the fault codes or the incorrect wiring is discovered following the Repair Procedure outlined below.

We checked, and this fellow’s car did indeed have the reversed wiring. A swap of the wires and a new pump, and he was on his way.

How does this situation come to pass? I spoke to Tony Gill, who heads Land Rover tech support at Autologic in the UK. He suggested a few possible answers.

This car seemed to have the wrong software put in at the factory, As a result, it may have never tried to use the auxiliary pump because the engine controller didn’t know it was there. Non-supercharged Rovers don’t have this pump. Of course, that does not explain how this truck went four years looking for cam adjusters that were never there . . .

It’s also possible that the pump was strong enough to push coolant through the supercharger backwards, against the flow of the regular water pump. It may have done that for all this time, and finally decided to fail.

We may never know the full answer, but it does appear to be fixed.

The moral of this story . . . check your software. Even in new vehicles, mistakes happen. And some of them take a long time to find. It’s shocking to me that there are four-year-old vehicles out there with wiring that was backwards from Day One, but it’s indisputably true.

That is the wonder and magic of British Motorcars.