Monday, October 12, 2015

Engine Noises and Surprise in a Porsche 911 -

How often do seeming disparate problems converge with symptoms that seem to go together?  It’s rare but it happens.

This car – a 2003 Porsche 911 C4s - came in with a nasty rattle in the engine, and a fault code for a camshaft position error.  Like most mechanics the owner took that to mean the tensioner or the intermediate shaft bearing had gone bad, and the engine was in imminent danger of self-destructing.

We saw no reason to disagree with that assessment, and we expected the diagnosis to be validated on teardown.  When we installed the holding tools to keep the cams and crank lined up we found one cam slightly off.

But when we removed the transaxle and looked at the IMS bearing it was tight. 

There were no signs of metal in the oil.

All we found was slight grab marks on one tensioner, indicating it may have slipped back a bit.  We therefore had an explanation for the slack. But we didn’t have an explanation for the nasty rattle.  We looked inside with a fiber optic camera, and saw nothing.

The technician decided to put the flywheel on the engine, fit new tensioners, a new IMS bearing, and start the motor to listen without the transaxle in the way.  When he did, the result was surprising.  The cam position fault was gone, but the noise was unchanged.  The clatter sounded just like it was coming from the timing chains.


But it wasn’t.  As you see in this short video the noise was emanating from the flywheel.


With a new flywheel and new tensioners, the cam faults were gone, and the rattle was fixed.


The dual mass flywheel was not visibly bad, but its slop was at the extreme limit of the acceptable range.  The noise was obvious, though, once it was twisted hard.   

What is the takeaway from this?  Sometimes two totally different problems will appear virtually at once, and by combining their symptoms you can imagine a very different diagnostic path.  Many times motorists come to us with a list of problems and the hope that there is one thing - the magic bullet failure - that will cure them all.  We have to explain that worn brakes and oil leaks have nothing to do with one another.  And rarely - as in this case - the opposite happens.  A car comes in with seemingly related symptoms, but in reality it has two totally independent failures.

Many techs would have changed those tensioners and then reassembled everything. And from outside, the noise would have seemed like chain noise for sure.  The next step – an unnecessary engine teardown.

No matter how much you know, cars can always surprise you

(c) 2015 John Elder Robison
John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Porsche restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the Porsche clubs, and he’s owned and restored many fine specimens.  Find him online at or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick.

Thursday, September 24, 2015

VW, and the automotive scandal of the decade

A Volkswagen product from a happier time . . .1967  (c) J E Robison

This week we have seen the revelation that VW engineers programmed their new diesel cars to sense when they were being tested for emissions, and when that happens to put the car into a special “low emission test mode.”

In normal mode the cars run better, but according to news reports the emissions can be 10 to 40 times higher.  Of course engine tuners have always known that truth – the tuning where a car runs best is very different from the tuning where it pollutes least.  Indeed, least pollution may equal minimal drivability in some cases.

VW owners have reacted with outrage.  They are particularly upset at the carmaker’s deliberate and premeditated action.  The brazenness of this goes beyond any automotive scandal in my memory.

At first the problem was thought to affect “just” 500,000 VW diesels in the USA.  Now VW has said up to 11 million cars worldwide may be affected.  Apparently they gamed the emission test system elsewhere in the world too.

The thing that sets this apart is VW’s seeming admission that they designed car software to deceive.  Ethically, that is a big step beyond overlooking a marginal design, or ignoring a flaw that would be costly to correct.  It’s like answering your cell phone from a brothel and telling your wife you’re in church.

The closest parallel to this situation that I can recall in the auto industry is the odometer tampering scandals of the 1980s.  In those years odometers were mechanical. They could be taken apart and altered with nothing more than a few hand tools.

At the same time, there was no system of checking odometer readings at state inspections, or even when ownership changed.  You could buy a car with 60,000 miles in one state, and sell it in the next state with 24,000 miles, with virtually zero chance of getting caught.  People in the trade called that job “clocking.”

Sleazy dealers were making fortunes; purchasing high mile lease cars at auction, shaving tens of thousands of miles from their odometers, and selling them at auctions in other states.  A truckload of cars altered in that way might earn the dealer ten thousand dollars or more, and there was almost no limit to how many cars could be clocked.

The situation became so bad that the FBI got involved in a big way.  They busted one dealer after another in sting operations and by following cars from auction to auction as the miles fell away.  In most cases, the perpetrators went to jail.  It was Federal time.

I still remember an interview with an FBI agent, who was asked why clockers got multi-year prison sentences when there was no violence.  In many cases clockers were going to prison for as long as a street criminal might go away for armed robbery.

“It’s the cold premeditated nature of it,” he said.  “A robber or murderer can say his was a crime of passion or desperation.  Setting an odometer back is a planned deliberate act.  You can’t say you didn’t know it was wrong, or you didn’t know what you were doing.”

In those days the clockers themselves and the dealer principals went to prison.  The clockers for doing the deed, and the owners for ordering it done and profiting from it.

Will VW executives face a similar reckoning?  The premeditation is the same.  They knew is would not pass with the tuning used on the road, so they made a special tune for the test stand.  The financial loss to consumers is the same too.  With clocked cars, owners paid more than the car was worth thinking it had fewer miles on it, and more life left in it.  With a diesel VW consumers paid more for the “green” engine and now they have a car that is significantly devalued now that the “green” deception is exposed.

Millions of people bought VW diesels based on their performance that was gotten by cheating the emission laws.  If the cars are modified to comply with law, and the performance suffers, VW could find itself buying back a boatload of vehicles.  They’ll be salable at some price, but the cost to VW could be huge – billions of dollars in the US alone.  If the cars are modified and people keep them, there is still the issue of broken trust.  If they cheated on the emissions, did they cheat on crash safety?  The loss of future sales may cost billions more.

But before they can do that, they have to get the cars brought in for recall.  If the car loses performance and economy, what owner would voluntarily agree to do that?  State action may be required, and they will harm VW’s image even more.  Today less than half the owners whose cars are subject to recall actually get the recalls done.

VW says have set aside money to pay for a fix, and to compensate owners.  But is money enough? 

Saturday, September 19, 2015

We Have A Winner! The British Invasion Car Show

At the concours at today’s 2015 British Invasion motorcar show in Stowe, Vermont . . .

Gus & Christine Bjorklund of Chelmsford, MA took 3rd place in a black 1978 Bentley T2 sedan

Modern Car Society president Jim Facinelli drove all the way from Pennsylvania in his 1989 Silver Spur to take 2nd

1989 Rolls-Royce Silver Spur - Jim Facinelli  (c)2015 JE Robison
We presented John Rando’s 1972 long wheelbase Silver Shadow, for a 1st place win.  As 1st place winner I had an opportunity to speak for a moment and I think the audience was surprised to hear I am autistic and the detail they saw in this vehicle is in part a manifestation of my autistic fixation on motorcars.  I also thanked the car's owner John Rando for his support of us, and making this restoration possible.  It's funny . . . millions of people have read my books and writings on autism but I'll bet that part of my life was unknown to 99% of the people at that show.

There was a very nice 1927 Bentley from Quebec.

Paul and Catherine Stanley’s 1951 Bentley Mark VI took Best in Show, from Gloucester MA

Finally, out on the people’s choice field there were 12 more Rolls-Royce and Bentley motorcars, and two for sale in the corral.

In the Land Rover area my friends David and Shelly Rifken brought their two Land Rover Defenders

My son drove up our 1990 Jaguar XJ-S convertible

And the field was filled with 650 magnificent British cars on a fine early fall day

We had a great time at the how.  It's always good to see our friends from the world of collector cars.  And thanks to everyone at Robison Service and of course my family for making it all possible.

(c) 2015 John Elder Robison
John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Land Rover restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the Land Rover clubs, and he’s owned and restored many fine Rovers.  Find him online at or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick.

Thursday, August 20, 2015

We guarantee your car will be fixed right, on time, and within budget.

We guarantee your car will be fixed right, on time, and on budget

That is a common statement in the auto repair world.  It sounds great, but how realistic is it? Auto repair is one of the top sources of consumer complaint, with most complaints being repairs that are not right, not on time, not on budget, or some combination of the three.  Which is off base - the repairs or the expectations?

In my opinion, the requirements to complete a job can only be known once the car has been dismantled enough to fully understand what’s needed and how much time and material will ben required. The hard truth is, we are in the business of repairing things, and just as in repairing people, there can always be surprises and complications.  

Motorists often misunderstand what service professionals can know. For example, we look at a car with worn tires and we say, new tires are $xxx.  It seems simple to price out tires, mounting, and balancing.  But what if the tires are dismounted and one of the rims turns out to be cracked?

Suddenly we have a $500 complication – a new rim is needed.  We can’t put the broken rim back on the car because it’s unsafe, and the motorist is left with no choice but to buy a new rim.

Most shops would have quoted a set of tires without any teardown at all.  And they would be very likely to have a customer relations problem when the broken rim was discovered.  This is not a common occurrence – 99% of tire repairs proceed smoothly.  But it can and does happen.

The question is, what can mechanics do about it?  In my opinion we start by setting the correct expectation.  We tell people that tires are $xxx, but there could be surprises.  The rim is one example; as cars get more complex the service complications become more numerous and more common.

You don’t get a promised cure at a guaranteed price at the doctor’s office.  You may pay x dollars for a certain treatment, but there's no guarantee that's all you need to be cured. You may need a lot more. You may be incurable. Why is car repair different?  It’s not, but people mistakenly assume it is. To a large extent that’s because mechanics set unattainable expectations and then they allow themselves to be painted in an unfavorable light for not living up to an impossible standard.

The way we correct that is by being clear what we can control in the offered service, and what we can’t.  Tires are a commodity; we can quote the price for different brands.  Mounting is a standard service too; we can quote time to mount tires on the rims we see.  Most of the time, that’s all that’s involved in a basic tire job. But when we give the motorist those figures we have a duty to inform them of the possible complications.  Some will say, what’s the worst case?  That’s impossible to answer most of the time.  In medicine the worst case is, you die.  In car repair the worst case is, you need a new car.

99.9% of the time those dire complications never come to pass.  But people get old and die, and so do cars.  Treatment and service outcomes will not always be good.  The best we can do as service managers is to disclose what we can, and paint a realistic picture.

Doesn’t the customer always have the last word?  That can be a misconception.  Take the example of the broken wheel rim.  Once discovered, we cannot undo the discovery, nor can we always retrace the steps to get there.  The customer may say “put it back like it was” but sometimes we can’t. The forces to mount and dismount the tire may turn a cracked rim into a cleanly broken one.  There may be no path but forward, and the only choice the motorist has is to buy a new or used wheel rim.  Using the rim he arrived with may simply not be an option.

We may take one thing apart for repair, only to see another broken thing beside it.  If that broken thing is a possible safety hazard, we place ourselves at risk if we do not fix it, so the customer in that case does not have the ability to decline a repair that would compromise safety. They can of course halt the whole job and tow the car away, but that does not do them much good.  The newly discovered safety hazard becomes part of the current repair cost, no matter who does it.

The only options then are abandoning the car, fixing it now, or fixing it later.  At one time cars were simple, and “fix it myself” was an option for many owners but with today’s need for dedicated test computers and special tools it’s a rare owner who has that option.

Here’s the hard truth:  Taking a car apart to evaluate damage may render it inoperative until fixed. Hospitals warn patients in advance when they undertake risky procedures.  Those of us in the auto service business have a responsibility to do the same.

Another common situation is the multi step repair.  Here’s an example:  A car comes in with an inoperative oxygen sensor, and the check engine light is on.  We see the failed sensor and replace it.  A week later the light is on again.  This time the newly repaired oxygen sensor is sniffing an out of range condition, and we repair that next.   It was not possible to see repair #2 without the prior completion of repair #1.  Whenever we repair engine lights we always warn motorists that more than one round may be needed because there are a thousand things that can illuminate that simple light, and they may reveal themselves one by one.

If this sounds complex, costly, and scary, I agree!  Yet it is the world we live in.  Some motorists would accuse me of making excuses in this essay, to which I would ask: Do you say that to your doctor?  Medical treatment and car repair are the two services most of us buy with some regularity.  Medicine is notoriously unpredictable in its outcomes, and costs have skyrocketed in recent years.  Car repair costs have risen too, but to a much lesser degree, and I submit that our outcomes are often more predictable. The fact is, service is more complex than most people know, and the best we can do is predict what will happen "most of the time."  

I've explained this to people, only to have them say, "A good mechanic won't have those problems.  It's the incompetent people that are the problem!"  Competence is a big issue in the auto repair field, and in the absence of standards and certification, a qualified tech is hard to find.  But the thing is, the most competent mechanic in the world still can't see inside your car without taking it apart.  None of us have x-ray vision.  Surprises and complications happen to the best of us.  To say otherwise is to deny reality.

From the shop’s perspective, our duty is to keep our training up to date and make sure we have the latest tools for the jobs we undertake.  We need to use our best abilities to diagnose vehicles, and report our findings promptly and clearly.  We need to be at the top of our game, and do our level best to get good outcomes.  At the same time, we have to be clear to our clients with respect to what may go wrong and why, and what we can do.

That is particularly true for a shop like ours, where we specialize in difficult jobs, and may of the cars we work on are referrals from other shops.  The "easy fixes" have already been tried, without success.   How does one estimate what it will take to go forward to the end?  Many times, we can't.  We can only price each step as we take it.

Often we take step 1 without even knowing what step 3 might be, or if there will be a step 4 or 5.  We have to be flexible and figure a path as we go.  Medicine and other complex diagnostic processes work in a similar manner.  You do a test, and that leads to another test, and a treatment, and eventually - you hope - to a fix or cure.

Cars are complex and service is specialized.  Not every mechanic can fix every car.  In a big shop like hours there are techs who specialize in certain brands (like BMW,) and others who specialize in certain procedures (like convertible tops.)  Knowing what we know, and what we don’t, is always a challenge and an exercise in humility.

(c) 2015 John Elder Robison
John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Rolls-Royce, Land Rover, BMW, Jaguar, and Mercedes restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the cr clubs, and he’s owned and restored many fine machines.  Find him online at or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick.