By Phil Arendt
A/C Blend Door Busted Or Electrical Issue
Question 1
I have a 2004 Mercury Sable LS sedan with electric temperature control. Many times the car will not give me heat or A/C when selected. Changing the temperature setting, vent position or fan will not change the temperature of the air coming from the system.
Several years ago my
dealership replaced the heater control module but the problem has returned
and I am not sure it was ever fixed since it was intermittent. The
only way to get the system to work properly is to restart the car and sometimes
it takes several restarts. The car also had a leaking cowl on the
passenger side. That was fixed when the
dealership replaced the heater control module.
I think a blend door is
sticking and the restart gives the module enough voltage to move
it. I want to get to the root cause before I start spending dollars
on another fix such as yanking the dashboard and replacing the blend door.
Soon I am moving to the
desert southwest. I need the air
conditioner working at 100 percent. What
do you think is wrong? K.K., email
Answer 1
It is possible a blend door
actuator is not operating as designed especially since there was a water leak
through the cowl on the passenger side.
Unfortunately, to fix a problem such as this, tests must be
completed. Once tests confirm the
trouble the dash needs disassembly to replace the actuator. Good luck in your new home!
Faulty Wiring Causes Hard
Starts
Question 2Intermittently, the malfunction indicator light in my 2007 BMW 328i turns on. When it turns on the engine runs fine but is hard to start. When it starts the light turns on but if I shut off the engine and restart it might start without any trouble and the light is off. Sometimes I might need to restart three or four times before the problem goes away.
About a year ago the same
problem occurred. At that time I took
the car to a dealer. Tests found a
problem with an eccentric shaft sensor.
They replaced it and the trouble was gone until recently. I returned to my dealer but the malfunction
light was not on when they did their tests.
They did not find any problems.
The next time the light
turned on I took the car to a local shop that specializes in BMW repairs. They found codes indicating the sensor that
the dealer installed was faulty. I
returned to my dealer but of course by the time they looked into the problem
the light was not on. They tested the
sensor and it passed.
I’m afraid that one of these
days the engine will not start. Have you
heard of anything like this before? Do
you have any suggestions? L.C., email
The eccentric shaft sensor is part of a system named the Valvetronic system that automatically adjusts valve timing depending upon many engine conditions.
Since this is an
intermittent problem and seems to occur more often after the vehicle has been
parked for a while consider leaving the vehicle overnight at your favorite shop
so a technician can look into the trouble when conditions are more likely to
raise the issue.
Your description lends to
more of a problem in the circuit than in the sensor. A wiggle test of the wiring in the circuit
just might find a faulty connection is the cause of the trouble. Ask your favorite technician to consider this
the next time you visit a shop.
Steering Works But Not As
Designed
Question 3The SSPS light is on in my 2004 Suzuki Forenza. I purchased the car two years ago. Since then it hasn’t given me any trouble. The person that sold me the car provided copies of all the service records. The invoices show that he took great care of the vehicle. Also, there is no mention of any SSPS trouble.
The engine runs fine. Everything is working without any problems
but the light is on. I don’t have an
owner’s manual for guidance with this problem.
Should I be concerned about this?
M.T.H., email
Answer 3
SSPS is an abbreviation for
speed sensitive power steering. The
light indicates there is trouble in the system.
The power steering automatically adjusts assistance depending upon
load. Under normal conditions at lower
speeds such as parking maneuvers the power steering provides more assistance so
it is easy to turn into a parking space.
At higher speeds assistance is reduced because it is easier for you to
turn the steering wheel while making minor adjustments on straight roads or
around curves.
The system module utilizes
information delivered from several sensor inputs to the SSPS control
module. The information gathered
controls how much pressure is needed to turn the wheels depending upon
conditions. More than likely a sensor or
circuit has failed.
To determine a fault a
technician needs to perform tests. An
independent shop may not have the proper diagnostic tools so be sure to ask
before you make arrangements to leave the vehicle for repair. However, if your shop specializes in Suzuki
repairs more than likely the test equipment and an experienced technician is on
staff to do the work. If not, a
dealership will have the tools and expertise to resolve the concern.
More than likely once this
is repaired you will notice steering will not require as much effort.
Elusive Brake Fluid Leak
Question 4About a month ago the brake warning light turned on in my 2007 Chevrolet Equinox. It has a 3.4-liter engine and 66,023 miles. I checked the reservoir and found it low. I added fluid to the full mark. About a week later the light turned on again. I had to add more fluid. Then I went to a repair shop to have the brakes checked for leaks. The mechanic removed all the wheels and checked the entire system over but he did not find any leaks.
I have had to add fluid
again. If there aren’t any leaks, where
is it going? N.C., email
Brake fluid evaporates but nowhere as fast as it disappears in your vehicle. When it comes to brake system problems I can assure you your technician did a thorough job of inspecting the system for leaks. Be this as it may there is one place fluid can leak and be hidden. Ask your technician to check the power brake booster for fluid. Fluid can leak from faulty seals in the master cylinder into the housing of the brake power booster. I’ll bet that once he removes the master cylinder from the booster he will find fluid within it. If so, both parts need replacement.
Car Repaired But Technician
Unsure Why
Question 5The check engine light was on in my 2000 Volvo V70. There were no other problems as the car started and ran fine. I took it to my mechanic who has been servicing it for a few years. He did some tests and found a code indicating a problem in the antitheft system. He also found that his equipment would not communicate with the engine module. He tried to reset the system by doing something with the battery but afterwards his equipment still would not work with the engine module. He suggested that I go to a dealership for more diagnostic work but he does not think there is a problem in the engine module or any other module. He does not know why his equipment will not work.
Since his work the light is
off. He is not sure why. Now that it is not on should I take the car
to my dealership? Should I be concerned
that the car will leave me stranded?
L.D., email
Answer 5
There is always a chance for
any vehicle that a part will fail leaving the operator stranded, but no one can
determine the future. Be this as it may,
this should not be of concern.
More than likely your local
shop technician reset modules utilizing a procedure with the battery
cables. At this point it appears your
Volvo is operating fine. The check
engine light that was your concern is not illuminated and it appears your
vehicle does not exhibit trouble. After
all you know better than anyone how your vehicle feels and operates.
You can go to your local
dealership for diagnostic tests if it will ease your concerns but at this
juncture I don’t want you to spend hard earned cash on work that likely will
not find an issue that will leave you stranded.
Mystery Over Bent Spark Plug
Electrode
Question 6Eight months ago, I purchased a 2006 Mercedes-Benz C230 with 93,000 miles. It has a 6-cylinder engine, automatic transmission and now has 100,124 miles. It’s in great condition and since the purchase has not given me any trouble until two weeks ago.
I was driving along when the
check engine light turned on and the engine began to shake. I drove to my repair shop where a mechanic
found a code for a misfire. He checked
the spark plug of the misfiring cylinder and found the electrode bent. He checked the interior of the cylinder with
a scope but did not find anything wrong.
He speculated that some carbon must have bounced against the spark
plug. He replaced the part and all was
well.
A few days ago I was driving
when the check engine light turned on and the engine began to run rough just as
before. I returned to the repair shop
and the same spark plug suffered damage.
The man working on the car did some more checks of the cylinder with a
scope but sees no problems. He installed
another spark plug and the car runs fine.
What do you think
happened? Is the engine about fail? H.R.M., email
Answer 6
Carbon deposits that break
loose can damage a spark plug electrode.
Unfortunately we can only speculate that was the cause. With a high degree of automotive certainty
the trouble was not caused by a failure of a piston rod bearing or even
excessive wear at the wrist pin that secures the piston to the piston rod. If that was the case you and your technician
would hear knocking sounds in the engine.
Don’t be concerned over the thought of a catastrophic engine failure.
Another possible cause is
sometimes plastic in the intake manifold degrades, breaks off and ends up in a
cylinder. If the trouble surfaces again,
ask your technician to consider this suggestion as a possible cause. If this indeed is the case, replacing the
manifold will bring this issue to an end.
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 mailto:drgizmo@hotmail.com. 04/15/2013 ® DR. GIZMO © 1989 - Present
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