"Dr. Gizmo"
By Phil Arendt
Loyal Reader Makes Dr. Giz
Smile
Question 1
Hi, Doc Giz! I
enjoy your column a lot. I even read it
before the comics. I am 84 years old and
probably driving my last car, a Saturn. I find it hard to believe that
today's cars are more reliable. When car
computers showed up, we were told the days of "throwing parts" at
problems were over. In spite of trouble code readouts, it seems many
mechanics including those at dealers are as befuddled as ever and the art of
throwing in parts lives on.
Also, it's comical how upset
folks get over a red light on the dashboard. The red oil warning light
lit up on a 1977 Dodge Colt I owned just as we were about to depart on a
holiday trip. Everything appeared normal, so I put a piece of black
tape over the red light. It was still shinning when I sold the car several
years later! Yes, I know that serious damage can occur from ignoring
warning lights, but sometimes common sense gets ignored too. You seem to have about as much common sense as
anyone, so keep on writing, and I'll keep reading! What do you say? Your fan R.V., email
Answer 1
R.V. you made my day. Thanks for being a loyal reader. I’m sorry that you drive an orphan. So do I since General Motors and Chrysler
closed certain brands. The good news is
you can still have your vehicle serviced and repaired at your local General
Motors dealer.
Diagnosing vehicle ailments
is more challenging than ever. Computer
malfunction codes provide clues to the cause of trouble. The clues are a path to repair. Unfortunately often when one circuit has
trouble it affects others and this leads to installing parts that are not
needed.
As for the warning light in
your Colt, more than likely the oil pressure sending unit failed. Thankfully the oil pump did its job and was
not the cause of the trouble or your trip could have been delayed along the
roadside not far from home.
Failed Module Causes Multiple
Problems
Question 2
I have a 2001 BMW 330Ci with
turn signals that flash on the outside but the lights on the dash do not
blink. Also, once in a while multiple
warnings flash on the dash for the air bags, engine antifreeze coolant and
convertible top when nothing is wrong.
The convertible top stopped working but I’m not too concerned about that
right now.
I went to a repair shop for
these issues. They said tests did not
find any problems but they think the module that controls the lights needs replacement.
Does this seem right to
you? R.H.L., email
Answer 2
Indeed a body control module
controls the turn signals, warning lights and even the convertible top. If the circuit is in good condition without
faults such as loose or corroded connections it is highly likely the module
needs replacement.
Stripped Gears Overheat
Engine
Question 3
The engine in my 2006 Mini
Cooper S overheats. I replaced the
thermostat and antifreeze temperature sensor, but the problem persists. I also went to a repair shop to have them
check for a blown headgasket. They say
it is not leaking.
I love my car but I can’t
drive it with this problem. When I start
it in the morning I can only drive a mile before it overheats. What am I missing? K.R., email
Answer 3
You are not missing anything. The cause of the problem just has not been
found. Be this as it may, since the
engine overheats so quickly there is either major blockage in the system that
prevents coolant from circulating or the water pump is not pumping. Since the engine is supercharged, it is
possible the gears on the supercharger that drive the water pump are
stripped.
Ask your favorite technician
to consider this the next time the car is at a repair shop.
Spark Timing Is Key To
Engine Starts
Question 4
Recently, my 2002 GMC Envoy
with a 4.2-liter engine would not start.
When I cranked the starter the battery was strong and the engine turned
but it wouldn’t start. When this
happened I had the truck towed to a shop that has serviced the vehicle for a few
years.
A mechanic found a code for
a bad crankshaft sensor. After replacing
the part three times the engine still will not.
At first he installed aftermarket parts.
The last sensor was from GMC. Now
he is in the process of trying to determine why replacing the sensor has not
resolved the issue. Testing shows the
sensor is fine but the engine is not timed properly. I’m not sure what that means but I trust what
he is doing.
I need my truck. It’s my baby.
It has 89,000 miles and I have taken excellent care of it since it was
new. Can you help? L.S.M., email
Answer 4
Soon, your baby will be back
on the road. The timing issue could be
caused by an electrical issue in the engine control module, jumped timing chain
or even a faulty reluctor on the crankshaft.
The issue relates to when the spark plugs fire in relationship to the
position of the pistons. Apparently, the
moment the spark plugs fire is off and not within specifications. Right now your technician likely is trying to
determine if this is caused by a mechanical or electrical issue. Once he rules out one or the other he can
focus on the failed system. Test results
will be his guide.
Since you have taken great
care of the vehicle more than likely there isn’t an issue such as a jumped
timing chain due to excessive wear. One
issue your technician might consider is that sometimes the reluctor on the
crankshaft moves. This is the part the
crankshaft sensor utilizes to time ignition signals to fire the spark plugs at
the proper time.
Recent Purchase Burns Three
Quarts Of Oil In 1,000 Miles
Question 5
Recently, I purchased a 2004
Nissan Maxima with 124,000 miles from a private party. The car looked great and ran fine. The other day the motor cranked when I turned
the key but it would not start. It was
towed to a local repair shop.
The shop did some tests and
found a code for sensors on the cam shaft.
They also found that there was hardly any oil in the engine and upon
further inspection they found a lot of sludge in it. They filled the oil and replaced the
sensors. The engine still would not
start.
After unplugging the sensors
the engine started but it had little power.
They now think there might be something wrong with the timing
chain. They suggest disassembling the
engine to inspect the chain but they fear the engine is shot because of the
sludge.
When I purchased the car the
oil level was full. I drove about 1,000
miles since then and the oil level didn’t register on the dipstick at my shop. They added three quarts of oil and did not
find any leaks. Do you think the engine
is shot? H.M.O., email
Answer 5
This indeed is a situation
with many issues beginning with the purchase but let us focus on the
engine. It consumed three quarts of oil
in 1,000 miles. This indicates excessive
wear in the valve system or cylinders or both.
Since there likely is excessive wear in the timing chain and a heavy
accumulation of sludge, replacing the engine is the likely outcome. Probably the best and least expensive option
is to install a used engine from a low mileage salvage vehicle.
Also, in the near future it
might be necessary to replace the exhaust system catalytic converters. They have processed excessive oil from the
engine and may soon fail. Also, the
oxygen sensors might fail, too. Don’t be
surprised if they do.
Additionally, since this is
an expensive repair you might consider sending the vehicle to another shop for
a second opinion.
Chirping Noise Develops
After Power Steering Repair
Question 6
The power steering quit in
my 1999 BMW 528i. A shop replaced the
pump and belt. After the work the power
steering issue was repaired but a month plus later a chirping growling type noise
developed.
I returned to the repair
shop. They have determined that the
noise is not from the new pump and think that one of the other parts driven by
the belt is making the noise. They say
it could be caused by a bad water pump, alternator or tension pulley. As of yet they have not identified which part
causes the sound.
I have owned the vehicle
since it was new. I have taken great
care of it. It has almost 190,000 miles
and has not given any trouble all of these years. Is it possible my shop installed the pump
incorrectly or damaged another part during the process that now has caused
another part to fail? C., email
Answer 6
Congratulations for driving
nearly 200,000 trouble-free miles. It is
unlikely the technician did a poor installation of the power steering pump as
it has a mounting assembly that keeps it in alignment with other accessories
and the serpentine drive belt.
Certainly, mistakes can happen but it is highly likely that an issue
would have surfaced immediately after the installation and not a month or so later.
Considering the mileage and
age of the vehicle it is very likely another part has failed due to normal
wear. From what you describe the noise more
than likely is caused by a failed tensioner pulley assembly. This part places the correct tension on the
drive belt that turns the power steering, alternator, water pump and air
conditioning compressor. Replacement
should squelch the noise.
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. 10/28/2013 ® DR. GIZMO © 1989 - Present
