"Dr. Gizmo"
By Phil Arendt
Parts Replacement Not The Cure
Question 1
My 2006 Volkswagen GTI lacks
power and the check engine light is on.
The car has a 2.0-liter engine. I
had the same problem a few years back when the car was covered by the factory
warranty. The warranty has since
expired.
I took the car to an auto
supply store to have the engine tested.
The man at the store found three codes all related to the fuel pressure
regulator and some codes for misfiring spark plugs. He did not want to sell me a bunch of parts
because he did not know what caused all of the codes. He suggested that I take the car to a repair
shop.
The car acts the same way it
did when it was repaired a few years ago.
I found the receipt from the previous repair so I can purchase the same
part. The codes the man at the auto
parts store found are, P2294, P2293, P0087, PO300, PO303 and PO304.
If I replace the part that
previously failed, do you think it will repair the car? M.R., email
Answer 1
Take the advice of the auto
supply store employee. Some of the codes
are related to fuel system issues. Other
codes are for engine misfire issues that could be caused by a troubled fuel
system. The fuel system is highly
pressurized. If you do not follow
suggested safety procedures you could be injured, cause a fire or worse.
Now that I have warned you,
the trouble might be due to a failed fuel pump.
There are two pumps in your vehicle.
One is a delivery pump which is in the fuel tank and the other is a high
pressure pump on the engine.
Additionally, there is a fuel pressure regulator and sensor. Faults in any one of these parts could cause
the trouble you are encountering.
You could purchase the part
listed on your receipt and install it, but this may not cure the trouble. Since it is highly probable your purchase is
an electrical part you will not be able to return it for a refund or exchange
as the general policy at auto supply stores or dealership parts departments is
no refund or exchange of electrical parts.
Consider leaving this task
to a pro.
Dealership Not An
Option
Question 2
My 2002 Honda Civic failed
to start. When I turned the key the
engine cranked but would not start. The
car was towed to a repair shop where a mechanic determined that the green light
for the security system is not illuminating.
He asked me to bring all the keys to his shop. I brought all of them, but none started the
car.
Next he contacted a
locksmith. The locksmith checked over
the car, but could not determine the trouble.
Next, the mechanic replaced
the powertrain module but that didn’t fix the trouble. Then he replaced a module for the security
system. Now the green light works but
the car still does not start. My
mechanic reinstalled the old powertrain module and still the engine does not
start.
Now my mechanic wants to tow
the car to a dealer to have them check over the car. I don’t want my car taken to a dealer. They charge too much. Do you have any suggestions? D.T., email
Answer 2
It appears that your
technician has pinpointed the trouble.
The module for the Immobilizer theft deterrent system failed. Additionally, it appears that the powertrain
control module needs reprogramming. It
appears that your technician does not have the tool to reprogram it. Since this might be the case, he wants to
have a local dealership do the reprogramming work.
Certainly you can tell him
not to take the car to a dealership for this procedure. Ask him if he has a relationship with another
independent repair shop that has the equipment to do the work. If so, the other shop can reprogram the
module. If not perhaps, you can find a
shop to do the work or have the car taken to a dealership.
A/C Quits When Going Up
Hills
Question 3
On a recent trip in my 2003
Ford Focus the air conditioner would cut out when going up a hill. Once I returned home I discovered that
occasionally the a/c cuts out during normal driving. It might shut off for ten minutes and then
start up again. When the a/c quits, the
fan works fine and the vents respond to my preferences on the controls but cold
air doesn’t blow from the vents. I
checked the electrical connection on the compressor and cleaned it but this has
not made any difference.
I took the car to a repair
shop but tests found everything was working normally at the shop. The shop manager says I should wait until the
trouble becomes worse or bring it in when it’s not working.
What do you suggest? K.P., email
Answer 3
Some system designs allow
for the air conditioner compressor to shut off when the engine is under heavy
loads such as driving up a hill. This
may be normal but since it quits during normal driving there likely is a
problem.
There is a lot more to the
air conditioning system than meets the eye.
There are relays, a high pressure switch, a low pressure switch, an
engine control module, controls in the dash, the throttle position switch,
temperature sensors and more. Since the
system worked normally during tests it is next to impossible for a technician
to determine the cause of the trouble.
Be this as it may the trouble might be due to a poor electrical
connection.
Suspicion points to a poor
connection at the high pressure switch.
For some reason when designing the car the switch was placed in front of
the right front tire where it can be exposed to water and dirt. If you are so inclined check the plug and
terminals. If you are not an avid
do-it-yourselfer, ask a technician to do the work. Cleaning the connections and protecting them
with dielectric grease may cure this condition at least until the next time
they become dirty.
Transmission Has Seen Better
Days
Question 4
I have a 2000 Chevrolet
Suburban with a 5.7-liter engine and 139,000 miles. I decided to have the transmission fluid
changed. A shop drained the fluid,
replaced the filter and cleaned the pan.
The mechanic said he found a lot of black material in the pan. Since the service, the transmission shifts
fine when I first start out in the morning but after driving a few miles when
the transmission shifts from second to third gear it does not shift smoothly
into third gear. There is a pause before
it fully grabs and engages.
I spoke with the manager at
the shop that serviced the transmission.
His shop does not repair transmissions but after a short test drive he
thinks the transmission needs an overhaul or replacement. He suggested that I take the vehicle to
another shop for repair.
Do you think the
transmission needs an overhaul or is there something else causing the
trouble? F.T., email
Answer 4
There are vehicles that
travel well over 200,000 miles without transmission trouble and then there are
some that need a transmission two or three times during their service
life.
Tests should discover the
cause of the trouble. Since a technician
found excessive debris in the pan it is more likely than not the transmission
has come to the end of its service life.
An overhaul or replacement is the next step.
Weigh your options carefully
when selecting a course of repair. An
overhaul may only be covered by a one year warranty. A replacement transmission warranty may be
much longer. Also, consider price and
what your future plans are for the vehicle.
Time To Visit Another Shop
Question 5
I drove home from work and
parked my 2006 Volkswagen Jetta with a diesel engine. The next morning I started the engine, backed
down my driveway and the engine stalled.
I attempted to start it but it just cranked but would not start.
I had the car towed to a
shop that has been servicing it for the last few years. Once it arrived at the shop a technician
jumped it and started the car. He was
able to drive it into the shop but it stalled as he was pulling into his work
area. He did some tests but his
equipment will not communicate with the engine computer. The shop manager says it is likely the engine
computer has failed but he does not want to install one because he is not sure
this is the trouble. He suggested that I
have the car towed to a dealership. He
says that the equipment at his shop can’t program a new module.
Have you ever heard of
anything like this before? D.A., email
Answer 5
Without a doubt I have run
into troubles such as yours.
It’s not common for an
engine control module to need replacement but it does happen. Additionally, not all repair shops have the
specialized equipment to program this module.
Most independent shops use generic equipment that can do a great deal of
testing on many different year, make, and model vehicles but there are
limitations with generic equipment. When
it comes to programming engine computers many times manufacturer specific
equipment is needed. Most independent
shops purchase equipment for specific brands that commonly visit their shop due
to technician expertise and specialization in a certain brand of vehicles. Some shops may specialize in Dodge repairs
and the one next door may specialize in Toyotas.
Since your present shop
suggests towing the vehicle to a dealership there is no doubt a dealer shop
will have the tools to cure the trouble but there may be a nearby independent
shop that specializes in VW repair. If
so, you might consider towing the vehicle there for it is likely that shop
invested in the tools to communicate and program the engine control module.
Two Heads Are Better Than
One
Question 6
My 1998 Mazda 626 runs fine
when driving but when I stop for a light or in traffic the 2.0-liter engine
runs rough and stalls. I have owned this
car since it was new. It’s in great
condition. I have followed the suggested
service schedule in the owner’s manual.
It has 103,000 miles.
I took it to a local repair
shop that has been servicing the car for many years. The mechanic did not find any trouble codes
in the computer, but during a test drive the engine stalled. They tuned the engine and replaced an airflow
sensor. When this did not cure the
trouble they used smoke to look for leaks and did some tests on the EGR and
throttle sensor but could not find the cause of the trouble. He checked the engine module and wiring but says
everything tests fine.
Now the mechanic is at a
loss. The shop owner wants to take the
car to a dealer for tests. I trust their
judgment, but I would rather not have them take the car to a dealer. What do you think is wrong? L.S., email
Answer 6
It’s not time for the
technician to give up. Perhaps the shop
owner has another technician who can brainstorm with the assigned servicing
technician. Usually technicians working
together can determine faults.
Since there are no trouble
codes in the engine computer it is time to go over all test results and perhaps
redo some tests.
Since stalling can be caused
by faults in the exhaust gas recirculation valve or leaks at the intake
manifold the technicians might consider retesting these parts. Since smoke tests were performed for leaks at
the intake manifold they may consider smoke again or other methods to retest
for manifold leaks.
If the shop owner is adamant
about taking the car to a dealership shop he must have a good reason for this
decision. Consider trusting his judgment
for he knows the limitations of his equipment and level of technician
expertise. If he believes repairs exceed
limitations and has a good relationship with a dealership this option is another
path to a quick and lasting repair.
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@drgizmo.ws.
08/24/2012 ® DR. GIZMO © 1989-2012
