Sometimes space is limited in the newspaper so not all of the column appears every Friday. Last week was one of those incidence. Here is the complete column.
06/22/2012
"Dr. Gizmo"
By Phil Arendt
At Times Trans Shifter Fails To Unlock
Question 1
Intermittently, for the last
two years the shift lock in my 1998 Toyota RAV4 has been sticking. The occurrence was maybe once every two
weeks. Now it is getting worse. Before the trouble began I would start the
engine, step on the brake and the transmission shifter would move without any
trouble. Once the trouble began I
started the engine, pressed the brake pedal and the transmission shift would
not move. When this happened I could
turn off the engine and restart, press the brake and the transmission shifter
would move to reverse or drive. More
recently, I had to turn the engine on and off several times before the shifter
would move. Now it is to the point where
I need to override the shift lock by inserting a key in a slot before the
shifter moves.
My RAV only has 36,000 miles
and is in great condition. I have owned
it since it was new and I’m not about to get rid of it. I have taken it to two different repair
shops. Mechanics at both shops have done
tests but can’t determine the source of the trouble even though they have been
able to duplicate the trouble. I’ve
asked them to start replacing parts, but they are reluctant to do so. Do you know what is wrong? B.G., email
Answer 1
It certainly is not time to
dump the vehicle. I hope your mechanic
has not suggested this as a resolution to the trouble.
More than likely tests have
found all components have the proper voltage and are working at the time of
testing. What’s puzzling is if the
technicians encounter the trouble they should be able to determine which part
is failing. Be this as it may, it is
possible a spilled beverage or dirt is gumming up the shifter in the center
console. This is a condition that eludes
tests. Cleaning may cure the condition.
If the shifter and
electrical connections are clean in the console the most accessible part in the
system is the brake light switch. This
might have an intermittent fault.
Replacing it may be the cure but this is only a guess.
Ask your favorite technician
to take a chance on replacing this part because it has a history of failure.
Additionally, in the future
when starting the vehicle apply the brakes first and then turn the key to start
the engine. This procedure will activate
the shift interlock as soon as the ignition is activated.
Oil Smells Like Gasoline
Question 2
I have a 1997 Chevrolet Silverado
with a 4.3-liter engine and 80,182 miles.
I purchased the vehicle in 1998 from a new car dealer who used it for
demonstration purposes. It had 3,500
miles on the odometer. Since then the
truck has never given me any problems.
It’s in great shape. I have
changed the oil and filter every 3,000 miles and follow the factory schedule
for everything else. It’s almost like
new.
The trouble is that the last
time I changed the oil it had a gasoline odor.
Since then I have been checking the oil level more frequently. It seems to be rising and still has the odor
of gasoline. The engine runs fine. I have no trouble starting it and the gas
mileage has not changed.
The engine starts fine,
there is no black smoke from the exhaust, it does not misfire or stumble but
I’m concerned that gasoline is mixing with the oil. Is this due to a bad fuel injector? Will adding fuel injector cleaner solve the
trouble? Is there anything else I should
look for? S.E., email
Answer 2
Normally, a sticky fuel
injector causes hard starts and black smoke from the exhaust especially in the
morning before the engine and catalytic converter heat up. Your nose probably is not misleading you. If the oil smells like gasoline more than
likely gasoline intermixed with the oil.
This is reason for concern because gasoline mixed in the oil reduces the
oil’s ability to lubricate the engine.
This could lead to engine failure.
Causes for such a condition
are dirty or failed fuel injectors. Testing
the injectors is in order.
Additionally, the design of your
truck’s engine is somewhat unique. The
fuel pressure regulator and fuel lines are hidden under the intake
manifold. Any of these parts could
spring a leak resulting in gasoline mixing with the oil. Since your engine is running fine, and taking
into consideration the vehicle’s age, it is more likely one of these parts is
leaking and the fuel injectors are okay.
To determine if a line or pressure regulator is leaking the intake
manifold needs removal. Repair all
depends upon what trouble is found under the manifold.
Transmission Falters When
Hot
Question 3
I have a 2002 Volvo S60
turbo with a 2.3-liter engine and 157,000 miles. I have maintained the car according to the
book since it was new. Recently, the
transmission shifts fine for the first few miles but once I have driven about
10 miles it does not shift normally.
When it upshifts to the next gear it takes longer for the next gear to
engage. The transmission disengages
first gear and then it seems to go into neutral and then it engages second
gear. The engine revs a little in
between shifts and then second gear engages sometimes a little more abruptly
than usual.
These conditions are
intermittent and do not occur every time I drive the car. Some days I can drive thirty miles or more
without any trouble at all. On other
days after I drive ten or so miles the transmission acts up.
I have taken the car to two
different repair shops. Both shops checked
the computer for trouble codes and test drove the car. No codes were found. One shop updated computer software. The other shop flushed the transmission and
checked for computer codes and updates.
Both shops experienced the trouble during a test drive. Neither shop is exactly sure what causes the trouble
but one shop suggests replacing a valve body might solve it. Do you think this makes sense? N.N., email
Answer 3
Obviously there is no
guarantee that replacing the valve body will cure the trouble. Be this as it may, the valve body has a
number of solenoids and valves that direct hydraulic pressure to various parts
to shift the transmission. When a valve
is excessively worn or sticks the shift pattern and quality of the shifts can
be adversely affected. Certainly the
symptoms you describe might be resolved by replacing the part. Also, it certainly is much less expensive to
replace the valve body than to overhaul or replace the transmission.
Front Brakes Become
Excessively Hot
Question 4
After I drive a while the
front brakes in my 1998 Mazda 626 seem to get hotter than the rear brakes. I discovered this when I stopped in the
parking lot at work. I smelled something
and found the odor is coming from the front brakes. I spent the day at work and drove home and
encountered the same odor. I took the
car to a repair shop the next morning.
A mechanic said the brake
pads are fine but the rotors look discolored from heat. He said that the brakes are working fine and
the odor probably was due to heavy stop and go traffic.
The next day when I drove to
work the front brakes smelled and I thought I saw smoke coming from them. I called my repair shop and was assured the
mechanic did not find any problems.
Despite this the manager said I should bring the car back for another
look.
The next morning I drove
over the repair shop. A mechanic checked
over the brakes and agreed that the front brakes look as though they have been
hot but the wheels were turning normally so the brakes were not dragging which
would indicate a problem. Once I arrived
at work the odor at the front brakes returned.
I called my repair shop. They
sent a tow truck to pick up the car.
Two days have passed since
the shop picked up the car. The mechanic
can’t find anything wrong other than the brake rotors have a dark color. Do you have any suggestions? A.H., email
Answer 4
The fact that the brakes
emit an odor, smoke and are discolored is indeed cause for concern. The
technician at your shop needs to drive the car the distance you drive to work
under similar conditions. Once he
experiences the odor he likely will agree something is malfunctioning in the
brake system. Right now he may not think
there is a problem except that perhaps you have a lead foot and make jack
rabbit starts and stops or ride the brakes.
Give him authorization to drive the car the distance you drive to and
from work. He certainly will encounter
the symptoms.
A problem such as this can
be caused by a fault in the antilock brake pump, a stuck proportioning valve,
sticking caliper pistons or slides, a fault in the power brake booster,
misadjusted brake pedal push rod, faulty or misadjusted brake light switch, a fault
in the brake master cylinder, or condition such as a restricted hose or kinked
line.
There is no doubt your
technician has much to examine but he will find the cause of the trouble once
he drives the vehicle under conditions similar to your commute.
Height Of Right Front Corner
Drops While Driving
Question 5
After driving eight to ten
miles in my 2005 Land Rover Range Rover the front passenger side drops lower
that the rest of the car. I took the
vehicle to an import repair shop where a mechanic scanned the computer that
controls the suspension. He found codes
that indicated a problem, cleared the system and activated it to see if there
were any leaks at the right front strut.
The vehicle was parked all night in the shop but no leaks were found anywhere
in the system. He drove the vehicle 14
miles and the passenger front dropped.
When he returned to the shop he did some tests but could not find any
leaks or other problems in the system.
Now he is at a loss as to what is causing the trouble.
Can you help? R.M., email
Answer 5
Sometimes all the high tech
equipment available to a technician just cannot find the cause of a
problem. When this happens sometimes low
tech old fashioned methods can rule the day.
Since we know that there is a leak somewhere in the lines or strut at the
right front suspension soapy water applied to all the parts might bubble at the
site of the leak. If so, he will know
exactly which part has failed.
Since it is rather easy and
obvious to find leaks at a line he may find that the strut leaks in an area that
can only be seen when it is fully extended.
If the strut has sprung a leak, replacement should put an end to the
trouble.
Murphy’s Law Strikes
Question 6
I replaced the front and
rear brake pads and rotors in my 2004 Acura RL.
Before the replacement no warning lights were on in the dash. After the repair I backed out of my driveway
and as I started to drive away the red brake warning light turned on. The brakes worked fine. I returned home pulled the wheels and checked
all of my work and made sure the fluid level in the master cylinder was
proper. Everything looks fine. After I checked everything I went for another
ride. This time the yellow ABS light
turned on. The brakes still worked fine.
For many years I have been
replacing the brakes on my cars and have never had a problem like this
arise. Do you know what causes the lights
to shine? M.N., email
Answer 6
Sometimes, as diligent as a
person can be in repairing a vehicle trouble strikes. At this point, it is time to take the vehicle
to a repair shop to have tests performed on the anti-lock brake system. It’s possible something has failed but more
than likely the system needs resetting.
The trouble probably is not due to an error on your part. Chalk
this up to Murphy’s Law which is anything that can possibly go wrong will go
wrong at some time. It just happened to
be your time for something to go wrong.
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. 6/22/2012 ® DR. GIZMO © 1989-2012
TOYOTA IS RECALLING CERTAIN MODEL YEAR 2010 LEXUS RX350 AND RX450H VEHICLES, MANUFACTURED FROM NOVEMBER 28, 2008, THROUGH SEPTEMBER 1, 2010. THE ACCELERATOR PEDAL CAN GET STUCK IN THE WIDE OPEN POSITION DUE TO ITS BEING TRAPPED BY AN UNSECURED OR INCOMPATIBLE DRIVER'S FLOOR MAT.
