Dr. Gizmo Advice Column

 "Dr. Gizmo"

By Phil Arendt

Diesel Engine Sends Smoke Signals   

Question

My 2006 Volkswagen Jetta turbo-diesel with 189,000 miles is in great condition but there is an issue that needs repair.  When accelerating from a stop the engine bogs and a cloud of black smoke shoots from the exhaust.  Once the turbo-charger kicks in the engine runs great. 

I have not gone to a shop yet.  What would cause this problem?  J.N., email

Answer

As efficient as diesel engines can be your diesel needs help.  A cloud of black smoke is a sign of excessive unburnt fuel.

This condition might be caused by faulty fuel injectors, a fault in the exhaust gas recirculation system, a faulty mass air flow sensor, carbon build-up in the intake manifold, issues in the turbo-charger system and perhaps contaminated fuel plus more.

Once a technician performs tests including a test drive and careful monitoring of data he or she should be able to determine the exact cause and a lasting cure.

Keyless Entry System Needs Attention Of Experienced Technician

Question

The keyless entry in my 2005 Land Rover LR3 does not work.  I have two remotes.  Both remotes were tested at an auto supply store.  Both are working fine.  Also, when I use the switch on the dash the doors lock and unlock.  Is this something only a dealer can fix?  S.J., email

Answer

This can be repaired by an independent shop if they have a technician with Land Rover diagnostic and repair experience along with proper test equipment.  In your area you might have a shop that specializes in Land Rovers.  Search the internet.  If no independent shop has the tools and expertise, it’s time to make an appointment at a Land Rover dealership.

 Multiple Starter Motor Failure Raises Concern

Question

In the last year the starter in my 2003 Ford Explorer was replaced three times.  It has a 4.0 6-cylinder engine.  Right now it will not start.  When I turn the key I hear the familiar click, click of a bad starter.  It sounds the same each time it fails.

I’m having it towed to the shop that has been replacing the starters.  Each time they have replaced it they say nothing in the engine causes the starter to go bad.  They have been installing remanufactured starters so I have not had to pay for any of them except the original.  The last time they replaced it they suggested that I have them install a factory original starter but I declined because I would have to pay for it.  This time I might agree with their recommendation. 

I have owned the vehicle since it was new.  It has 81,000 miles.  I follow the factory maintenance schedule.  The truck is in good condition.  Is there anything in the engine that might cause the starter to go bad?  T.J., email

Answer

Generally, repeat failures are caused by broken teeth or cracks on the flywheel.  A starter gear engages this part to spin the engine.  I hope your shop has done a thorough inspection of it. 

Also sometimes failing parts in the transmission or engine might cause an excessive load on a starter.  Your shop might consider checking for issues such as a failing hydraulic pump in the transmission or failing bearings in the engine but with a year of trouble it’s doubtful either unit has a fault that is causing starter motor failures.  By now Issues such as these would have manifested into complete failures of the engine or transmission. 

More than likely, the trouble is caused by an issue such as a faulty connection, a heavily corroded negative or positive battery cable, flywheel issues or the starters are not up to the task.   Consider the installation of an original equipment starter after a technician considers these possible causes.

Reader Observation

Question

Thanks to Dr. Gizmo and my local newspaper I enjoy the weekly auto troubleshooting articles.  I have noticed a common thread in the help requests.  Nearly all the vehicles in question have high mileage and have been a pleasure for the owners.  Nearly all owners seem to avoid service at their brand's car dealer, mentioning "local repair shops", whatever that is.  I have nothing against unaffiliated repair businesses but for a tough, tricky car failure it would be logical that the brand dealer service people would have the best parts, tools and training.  I also believe that part of the strategy with long warranties on newer model cars is a big incentive for having service at the brand dealer.  What are your thoughts?  J.D., email

Answer

You are correct.  Dr. Gizmo rarely receives a complaint about a motorist’s vehicle choice.  He does receive a majority of mail regarding car problems in older vehicles.  Most requests are from readers who visit independent repair shops and avoid going to dealerships for repairs and preventive maintenance.  A majority of them feel price at a dealership is their concern.  Many state inconvenience, too.   

In almost every instance readers love their vehicles and take great care of them.  They keep them for a long time.  When something breaks they often ask for a second opinion or they are at their wits end with a condition their shop can’t repair.  In such a scenario many independent shops have suggested a dealership is the next step to a successful repair.  Often an independent shop will take an afflicted vehicle to a dealership for their customer.

You rarely read about low mileage vehicles in this column due to the factory warranty period.  New car owners take their vehicle to a dealership for warranty repairs.  With bumper to bumper warranties of 36,000 miles or more and a 100,000 mile warranty on the engine and transmission it would make sense to take a vehicle to a dealership.  Also, many new vehicles come with preventive maintenance packages with a new car purchase.

Diesel Truck Fails To Start

Question

My 2004 Ford Excursion with a 6.0-liter diesel engine won’t start.  When I turn the key on all the lights on the dash light up normally.  I wait for the glow plugs to heat up and then I turn the key to start.  When I do the engine cranks but it does not run.  I have cranked so much the batteries needed charging but charging did not get the engine running. 

The truck is in great condition.  I love my diesel.  I do a lot of the maintenance on it.  It has 141,000 miles and has been well maintained.  What would cause this problem?  R.M., email

Answer

I’m sorry to hear of your plight.  This might be due to a blocked fuel filter.  Perhaps a fuel pump has failed.  Maybe a fuel injector control module has failed.  Perhaps the anti-theft system is preventing starts.  Maybe the glow plugs are not heating up. 

I understand that you enjoy doing preventive maintenance tasks but at this juncture the job of repairing this condition might be something beyond your expertise.  It’s time to send your truck on an excursion to your favorite repair shop.

Misfire Continues Despite Installation Of New Parts

Question

My 2003 Chevrolet Silverado 3500 has 183,000 miles and a 6.0-liter V8 engine.  I’ve owned it since it was new.  I change the oil and filter every 2,500 miles and have kept up with other maintenance according to the factory schedule.  It has never let me down.

When the engine is idling, I feel a slight misfire.  I replaced the spark plugs, ignition wires and fuel filter.  A friend who knows a lot more about engines than me said that sometimes a bad crankshaft sensor causes the trouble so I replaced it.  This work has not cured the problem. 

I went to an auto parts store for testing.  The employee found a misfire code in cylinders 5 and 6.  I replaced the spark plugs again in those cylinders but the problem continues.  Can you help?  M.J., email

Answer

The symptoms indicate an issue that might be the result of a leak at the intake plenum.  The two afflicted cylinders are connected through the plenum.  There might be a leaky seal or gasket.  It’s also possible a vacuum port is connected at that point on the plenum and a vacuum hose is cracked. 

Since the engine has pushed the truck many miles it’s possible there is excessive wear of the valves at those cylinders. It’s also possible the camshaft is excessively worn. 

Check for leaks at the plenum and vacuum hoses.  Do a compression test on all the cylinders.  What needs repair depends on your findings.  Good luck with this project.

   

Thank you for all the great questions.  Dr. Gizmo can’t wait to answer more.

Phil Arendt is a columnist, consultant and A.S.E.-Certified Master Technician.  Readers may send questions to Dr. Gizmo at P.O. Box 548, Cary, IL. 60013 or e-mail address drgizmo@hotmail.com.   11/02/2015 ® DR. GIZMO © 1989 - Present