06/08/2012
IF YOU MISSED IT, HERE IT IS!
"Dr. Gizmo"
By Phil Arendt
Automatic Trans Fails To Shift Automatically
Question 1
When I shift the
transmission in my 2007 Chevrolet Silverado into drive it does not move. If I shift from drive to first gear I can
manually shift the transmission from first to second and third gears. There are no problems with reverse gear.
I checked the transmission
fluid level. It is full and is not
discolored. It does not have a burnt
odor.
My truck has 83,000
miles. The check engine light is not
on. Do you think the trouble is caused
by an electrical problem or is the transmission shot? W.R., email
Answer 1
Generally, the check engine
light illuminates when there is an electrical fault or sensors detect
conditions such as slipping clutches. Be
this as it may, a problem such as this could be caused by an electrical problem
such as a failing range selector switch, glitch in the transmission control
module, sticking or worn solenoids in the valve body or broken part in the
transmission.
At this juncture, ask an
experienced transmission specialist to diagnose the trouble. Tests of the range selector may find it needs
replacement or there indeed is a broken internal part.
If there is a fault in the
range selector or failing solenoid in the valve body the transmission does not need
removal, overhaul or replacement. If
there is a failed part deep inside, the transmission needs removal and
disassembly. This likely will lead to an
overhaul or replacement of the unit.
Speedometer and Antilock
Brakes Quit
Question 2
The speedometer quit working
in my 2008 Volkswagen Rabbit with a 2.5-liter engine, manual transmission and
43,000 miles. When the speedometer quit
the antilock brake light turned on in the dash.
Is there a failed module or wire in the instrument panel that is causing
these problems? Right now the brakes
seem to work fine. Will they suddenly
fail? T.D.P., email
Answer 2
Do not worry. It is 99 percent likely the brakes will
continue to stop the vehicle without the antilock brake feature. Until this is repaired employ squeeze braking
technics in emergency situations to help avoid a collision as the antilock
brake function will not pump the brakes under conditions that trigger the
system to do so.
Since your vehicle is
equipped with a manual transmission, it is likely vehicle speed information
that signals the speedometer is provided by the antilock brake system. A fault in the antilock brake system such as
a failed wheel speed sensor shut down the antilock brake system and the
speedometer. Tests may find a wheel
sensor, wiring or perhaps the antilock brake system module has a fault. Once repairs are complete on the ABS it is
likely the speedometer will return to normal function.
Stalling Problem Eludes
Diagnosis
Question 3
Intermittently, my 2000
Pontiac Grand Prix stalls without warning.
Sometimes I can drive a month without it stalling. At other times it may stall twice in one day. I just never know when it may stall. When it stalls it usually does not restart
right away. I may have to wait an hour
before it will start. It’s as though
something needs to cool down. Once it
starts it runs fine as though nothing was wrong.
I’ve taken the vehicle to
three different repair shops. Mechanics
have done several tests. They have
checked the fuel pump pressure and computers for codes. One shop replaced an ignition module. Another shop replaced a module in the dash panel. The last shop did many tests and found codes
indicating trouble in the security system, but the mechanic doubts that a fault
in the system is the cause of the trouble.
He says the codes are in a computer history file and are not current
codes. He says all the systems are
running normally. He said that codes 1626,
1629 and 1811 do not make sense so now he is at a loss as to why the car
stalls.
The car has never stalled
for any mechanic. Combined they have
driven nearly 200 miles and have run the car for hours in the shop without the
engine missing a beat. I love my car but
being stranded is frustrating. I have
owned it since it was new. I have taken
great care of it by following the owner’s manual schedule. It looks like new inside and out, but if this
is not fixed I really don’t know what I am going to do. Right now purchasing a new car will place a
heavy strain on my budget. Does this
make any sense to you? Can you
help? K.B., email
Answer 3
Your literation does indeed
make sense. I can at least help close the
curtain on this scene. The 1600 codes
are not current so it appears that the technician who replaced the instrument
cluster module repaired trouble in the theft deterrent system. The 1811 code is related to a transmission
shift issue that indicates that shifts are longer than normal according to programmed
specifications in the computer. This
will not cause engine stalls but might indicate that the engine control module
needs an update but don’t worry over this minor issue.
Since a technician replaced
an ignition module that did not cure the condition I suspect the signals that
trigger the computer and ignition module to fire the spark plugs sometimes are
not present. This could be caused by
corroded electrical connections and might be caused by a fault in the
crankshaft sensor. Also, sometimes a
problem such as this is caused by a mechanical problem such as excessive play
in the crankshaft or vibration dampener pulley on the crankshaft.
A check for excessive wear
of the crankshaft is warranted especially if the car has excessive
mileage. If there is excessive play in
the crank shaft the engine needs major repairs.
If the vibration dampener is the cause of the trouble, replacement
should cure the stalling.
Testing the crankshaft sensor
and associated wiring is necessary. If
the wiring is okay, testing the sensor may find a fault but often this sensor
passes tests even though there is a fault so ask your technician to consider
replacing the part even though it is only suspected of being the cause of the
condition. Replacement could end your
woes.
Engine Loses Its Cool Due To
Hidden Leak
Question 4
During the hot holiday
weekend the engine temperature in my 2007 Chrysler 300 went to the hot
side. I checked the coolant level in the
overflow tank and found it was empty. I
added premixed coolant that I purchased at an auto supply store to the full mark
on the tank. The engine temperature
returned to the normal range after adding most of the one gallon
container.
Once I was home I checked
for leaks but I did not see any. Nothing
is leaking on the ground. I can smell
what I think is hot antifreeze in the engine compartment. I also found the antifreeze level in the tank
dropped a little so I added the remainder of the gallon of antifreeze to top it
off.
After two days of driving
the engine temperature was near hot levels.
I checked the tank and it was low.
I purchased another gallon of premixed antifreeze and added it to the
tank to the full mark. The temperature
dropped just as it did before.
I still cannot find any
leaks. Nothing is dripping on the ground,
but there is this odor of hot antifreeze.
I think it is coming from the front of the engine but I don’t see any
leaks. My car has a 2.7-liter engine and
120,000 miles. I know there has to be a
leak somewhere. Do you have any
suggestions? L.G., email
Answer 4
Overheating is an emergency
situation. It can ruin an engine in
seconds. Connect an antifreeze I.V. to
the coolant tank. Hang a one gallon jug
of premix coolant on a vertical object such as an antenna to keep fluids at the
full mark.
All kidding aside your nose
has found a leak. The trouble is that
you cannot see it. More than likely the
water pump is leaking. The weird thing
is that often leaky pumps do not leak when the engine is off. Also, the water pump in your car is under a
cover on the front of the engine so a leak is hidden from visual confirmation.
Ask your favorite technician
to consider this is the trouble. More
than likely he will agree and replace the pump after he removes the cover. Also, since you have been diligent in keeping
the coolant surge tank full, and the engine temperature down, there should be
little worry of damage to the engine due to overheating.
Power Window Fails Due To
Wiring Problem
Question 5
The passenger window in my
2005 Chrysler Sebring quit working. It
does not work from the right door switch or driver’s door switch. I checked all the fuses. They are fine. I also removed the panel on the door and
examined all of the wiring. Everything
looks good. I used jumper wires and
found that the motor works fine and the window goes up and down smoothly.
Is there anything else I
should look for? D.L., email
Answer 5
Since the driver’s main
control switch does not operate the right window it is likely there is an open
circuit that is not inside the right door.
Check the wiring inside the flexible rubber conduit between the door and
door frame. More than likely you will
find a broken wire in the harness within the conduit. Repair all depends upon what you find but
more than likely a heat shrink style butt connector will repair a broken wire
in a flash.
Additionally, a broken wire
within the conduit of the right door is a little unusual. If indeed a broken wire is the trouble it
usually occurs in the conduit at the driver’s door. If you do not find a broken wire at the right
door, check wiring at the left door conduit.
Motorist Blows A Fuse Over
Failing Cruise Control
Question 6
Intermittently, the cruise
control in my 2000 Toyota Avalon quits working.
It may work fine for months and then I can be cruising along and it
quits.
The first time this happened
I checked all of the fuses and found a blown fuse in the driver’s side fuse
panel. I replaced the fuse and the
cruise worked fine. Since then the cruise
has been quitting once in a while. I
carry a box of fuses with me. Whenever
it quits I pop in another fuse. It’s
been a couple of years since the first time it quit and now it quits at least
once a week.
Now that the trouble is
getting worse I’m about to blow a fuse. Is
this caused by a short in the cruise control box under the hood? Will replacing it cure the trouble? F.B.,
email
Answer 6
Don’t blow a fuse over this
condition. It’s not time to replace the
cruise control module. Normally, a
problem such as this is not caused by the module. If a fault develops in the unit it usually
fails and the system does not function at all.
What appears to be causing the trouble is a shorted wire between the
passenger compartment and engine compartment.
It may be in the dash, steering column or harness in the engine
compartment.
To find the afflicted wire
it will take an experienced technician time to probe for the cause but more
than likely he will find the trouble in the steering column, dash or wires to
the brake light switch.
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. 6/08/2012 ® DR. GIZMO © 1989-2012
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