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Saturday, March 23, 2013

Dr. Gizmo Column


"Dr. Gizmo"
By Phil Arendt
Former Dealer Loaner Car Gives New Owner Trouble
Question 1
Recently, I purchased a 2012 Honda Civic LX.  It was a dealership loaner vehicle.  I should not have purchased it because too many people drive cars like this one and sometimes abuse them.
The trouble I am having is that sometimes the ignition key will not turn to the start position.  At the same time the dash says to check the brake system.  When this happens after two or three attempts the key turns and the engine starts.
Other than this problem I am happy with the gas mileage.  It gets 40 miles to the gallon on the highway!  What do you suggest I do about the key problem? J.M., McHenry, IL
Answer 1
Wow, 40 miles to the gallon on the highway is fantastic!  As for the trouble turning the ignition key, before you turn it make sure your foot is firmly planted on the brake pedal.  If this does not cure the trouble it’s time to make a trip to your dealership where a technician might find that the trouble is due to a problem in the transmission shifter.  Perhaps someone spilled a soft drink down on the console and now electrical problems have developed.  A technician might need to replace the transmission shift assembly or he may find cleaning electrical terminals cures the issue.
Technical Service Bulletin Procedure May Fix Starting Trouble
Question 2
Two years ago the starter failed in my 1996 Ford Taurus.  The replacement failed after a month.  Six weeks ago the starter failed again and all was fine until a week ago. 
In the morning the car cranked fine but seemed to be starving for fuel and then caught and ran fine.  I went on my way and my next stop took an hour.  I went out and the car acted up again but started.  It seemed to miss or hesitate for a split second.  Then I went to a store and when I came out half an hour later, I hardly got it started at all.  It cranked and cranked and after maybe 30 seconds it finally started.  Of course the next morning it was fine.  I left it at my garage all morning.  They tested the fuel pump and whatever else they could and found nothing wrong.  It has been fine ever since.
I never let the gas tank get below half full.  I change the oil every three months and do whatever needs to be done according to schedule.  I even named the car and talk to it sometimes.  I love this car but it's getting to the point that it's stressful going anywhere in it.  Do you have any ideas what could be going on?  J.L., email
Answer 2
You are not along.  I have been told by good authority that a person living at a senior community in Woodstock has a picture of their car in their room.  The vehicle must have been very special.  Many car owners name their cars.  Also, many talk to them especially when they don’t start.
As for the trouble, your car has a reputation of starter trouble.  There isn’t much you can do about it.  As for now right now, since the engine starts and runs fine a technician would have to guess why it was not starting.  It would not be cost effective for you to leave it at a shop unless the car exhibits the symptoms.
When the symptoms surface return to your favorite repair shop.  Ask your technician to review service bulletins.  There are at least three factory technical service bulletins for this type of condition.  They address issues regarding the idle air control, powertrain control module calibration and fuel pump issues.  Once he reads these bulletins he should be able to determine the cause of the trouble.  With the procedures outlined in the bulletins the condition should be corrected. 
Battery Replacement Results In Computer Module Trouble
Question 3
I hope you can help.  The battery died in my 2007 Volkswagen Rabbit with a 2.5-liter engine and 107,000 miles.  I replaced it and afterwards the power windows, gas door and tailgate are not working.  I checked all the fuses and they are fine. 
A friend that knows a lot about cars told me that sometimes a module loses its memory when the battery dies.  He told me to take the battery cables off and tape them together.  He said this resets computers.  I did what he suggested but it did not work.
What do you suggest?  Do I need to take the car to a repair shop?  D.M., email
Answer 3
Yep.  Replacing a battery can cause problems.  Also, in some cases holding the battery cables together resets computer modules but as you learned not in your car. 
Before you take your car to a repair shop there is something to try.  This time disconnect the battery cables but do not tape them together.  Just leave them off the battery for a few hours.  After time has passed, reconnect them.  The module that controls the accessories may come back to life.  If not, visit your favorite repair shop where a technician will need to perform tests to determine the cause of the trouble.
Repair Not As Laborious As Portrayed
Question 4
The front differential is making noise in my 2005 Chevrolet Trailblazer.  I’m in the process of choosing a shop to do the work.  Each shop tells me that this is a big job.  They say it might be necessary to remove the oil pan on the engine just to get a shaft out. 
Is this true?  If so, Chevrolet really flubbed the design on this vehicle.  S.L., email
Answer 4
Part of the differential does pass through an opening in the engine oil pan.  Many years ago when I first saw this design I scratched my head and questioned the wisdom of the engineers who came up with the idea and designed such a mess.  While in my humble opinion it is not the best way to build a vehicle I also understand that auto engineers are given a budget and they need to stay within the budget to design and build a vehicle.  This resulted in your concern.  Be this as it may it is not necessary to remove the oil pan.  It’s still a pain in the neck repair but removing the steering rack and cooling fan and loosening the engine mounts provides the room to do all the necessary work on the front differential and axles.
Better Reconsider Tackling Repair
Question 5
My 2006 Honda Pilot EX with a 3.5 engine idles rough.  I had the computer tested and code PO505 appeared.  The parts store employee who did the test said that the trouble might be in the idle air control.  He suggested that I go to a repair shop to have the trouble investigated.  While I was there I purchased spark plugs and installed them but this did not cure the rough idle.  Also, installing the spark plugs was a weekend project I never want to do again.
Is there anything I can do about the trouble in the idle air control?  R.K., email
Answer 5
If you think replacing the spark plugs on your vehicle is tough you might consider taking the vehicle to a shop to have a technician tackle the other problems.  Compared to other vehicles the spark plugs in your vehicle are a snap to replace.
If you decide to tinker a little more, cleaning the port in the throttle body might cure the rough idle.  Also, the idle air control valve might need replacement so that’s something you might want to try.  If these procedures don’t resolve the issue there may be problems such as failed intake manifold seals or a broken vacuum line.
If the manifold is leaking, consider taking the car to a shop and let a pro handle the task.
Engine Stumbles, But No Cause Is Identified
Question 6
My 2002 Nissan Quest has a 3.3-liter engine with 105,000 miles.  When the engine is idling every once in a while the engine cuts out as if I quickly turned off the ignition and then turn it back on.  The engine does not stall, it just momentarily cuts off.  When driving the engine runs fine and does not cut off.  
I took the car to a repair shop.  The problem never surfaced for them.  They did a number of tests and found a problem with a knocking sensor.  They replaced it but the trouble is not fixed.  At this time they do not know what causes the trouble and suggest that I drive until the problem becomes worse.  Worse to me means that the engine stalls and leaves me stranded.
Do you have any suggestions?  M.K., email
Answer 6
This is the type of condition that is difficult to diagnose.  Since it only occurs at an idle all a technician can do is run the engine with test equipment connected, monitor patterns on a scope and wait for the engine to falter.  Once it does he can see what occurred then he can troubleshoot the circuit that is causing the issue.  Also, a technician can wiggle wires and tap on sensors in an attempt to induce the trouble.  There may be a sensor with a poor external connection or internal problem on a circuit board.  Perhaps there is a ground connection that is loose or impaired by corrosion. 
Perhaps these suggestions will successfully find the cause of the fault.  On the other hand there is no guarantee he will find the trouble but you will pay for the time he spends wiggling wires and monitoring a lab scope or other equipment.  Consider limiting labor time to an hour before he starts probing for the trouble.
Thanks for all of your 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 03/04/2013 ® DR. GIZMO © 1989-Present

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