"Dr. Gizmo"
By Phil Arendt
No Code For Troubled Air
Bags
Question 1
Our 2010 Chevy Impala is
showing that our air bags need service. My dealer mechanic says he doesn’t get a code. We have to bring it in again. Shouldn’t he be able to find a code? B.S., email
Answer 1
Yes and No. If the air bag system is working properly a
malfunction code should pop up when your technician performs tests. The issue might be that the air bag control
module has a fault. The result is what
you have experienced.
The control module knows
there is a fault and turned on the light indicating trouble. It just does not know the source of the
trouble resulting in no malfunction code.
More tests should determine why.
Collision Damage Causes
Leaky Transmission
Question 2
Several months ago I was in
an accident with my 2008 Chevrolet Uplander with an automatic transmission and
3.9-engine. My body shop repaired the
body damage and they replaced parts in the driver’s side suspension and drive
shaft. Since the repair, fluid leaks
from the transmission on the driver’s side where they replaced the axle drive shaft.
I’ve returned to the body
shop. Three times, they have replaced
the seal on the shaft. It was still
leaking so when I returned the third time they installed a seal from the
factory. They were confident a factory
seal would fix the trouble. It did not. Now they want me to take the van to another
shop that specializes in transmission repairs.
So far I have not had to pay
for any of the extra work, but inconvenience is a big problem. What could be wrong? K.N.W., email
Answer 2
I’m sorry to hear of your
plight. It’s possible that there is a
defect in the new axle shaft. It’s also
possible the body shop installed an incorrect shaft. Perhaps, the seal is incorrect. It’s also possible there is an issue inside
the transmission where there is too much play in the output shaft that connects
to the axle shaft. There might be a
small crack in the case where the seal mounts in the transmission.
While this issue undoubtedly
has caused much inconvenience it is a good idea to give a shop that specializes
in transmission repairs a shot on curing the trouble.
Make sure to contact your
insurance company about the issue before you take the vehicle to the next shop.
Parts Swap Needed On Newly
Installed Engine
Question 3
I have a 1993 Mercedes-Benz
400 SEL with a 4.2-liter V8 that I purchased two years ago. It now has 151,000 miles. It’s in great condition except recently the
valves bent in the engine. This has
turned out to be a huge project.
I decided to install a used
engine from a junk yard. The yard that
sold it to me said it has only 25,000 miles.
When I brought it home to my shop everything matched perfectly including
wiring harnesses. I didn’t have to swap
any parts with the old engine. I
installed it and it started right up and ran fine. I drove it around the block a few times and
parked it.
The problem is that the next
day it would not start. It had spark and
fuel but it still did not start. I
checked the spark plugs. They were wet
with fuel. I finally got it started but now
it runs rough, misfires and backfires in the exhaust. I’m at a loss as to why.
Do you have any
suggestions? N.T., email
Answer 3
Congratulations for tackling
this project. When complete you will
beam at your accomplishment.
As for the trouble, take
into consideration how long the engine probably has been sitting around at the
salvage yard. It could be 20 years. Since you did not swap parts from the
original engine to the salvage engine it’s possible some parts need
replacement.
Since the trouble appears to
be caused by issues in the ignition system it might be a good idea to check the
cap and rotor in both distributors. You
might find spider webs, dirt or corrosion inside them. If so, replacing them might get your Benz on
the road. If this isn’t the trouble
check the ignition coils.
Vibration Eludes Repair
Question 4
My 2000 Buick LeSabre
Limited with a 3.8-liter V-6 engine shakes when accelerating. My car is great condition. I follow the factory maintenance schedule to
the letter.
I took the car to my local
repair shop. A mechanic found cracks in
the front axle boots. He said all the
grease had run out of the constant velocity joints. He also found that one tie-rod in the
steering was bad and the motor mounts were bad.
He also checked over the engine and transmission. He said there are no
problems with either.
My mechanic replaced all the
bad parts all to no avail. The vibration
continues. Once I reach cruising speed,
the vibration stops. Do you have any
suggestions? R.M., email
Answer 4
Since the engine and
transmission are in good shape and all the worn parts have been replaced the
best advice I can provide is to replace the car. I’m just kidding. At this point ask your technician to consider
checking the tires and wheels. It’s
possible the wheels need balancing. It’s
also possible a tire or wheel has excessive run-out or is bent. There might even be a broken belt within a
tire. Since the issue is during
acceleration it might be a good idea to focus on the front tires. They are the drive wheels so an issue such as
a bent wheel could cause vibrations.
Original Equipment Part
Might Fix A/C
Question 5
The air conditioning in my
2007 Volkswagen Jetta with a 5-cylinder engine is not cooling as it
should. When stopped at a light the
temperature of the air blowing from the vents warms. Also, the temperature gauge on the dash goes
up. Once I start moving the engine
temperature goes down and the a/c cools down.
At cruising speeds everything works fine.
I went to my local repair
shop. A technician found that the
electric fans by the radiator are not working properly. One does not work at all and the other makes
unusual noises. He suggested that I take
the car to a dealership because he does not work on VWs that often.
I went to a dealership. Their mechanic determined that new fans were
needed so I returned to my local shop.
My local shop installed new
fans. They did not work at all so he
returned them and installed another new set of fans. They don’t work either. He says he is going to ask his parts supply
house to get parts from another source.
Does this sound right to you?
N.M.B., email
Answer 5
Yes. He correctly diagnosed the problem the first
time you brought the vehicle to his shop.
His diagnosis was verified by a dealership technician who likely used
factory diagnostic equipment to determine the cause of the trouble.
There is one thing your
local independent shop technician might consider. He is having problems with the parts from his
supplier. He might consider that
aftermarket replacement parts will not work in your car. Sometimes when this occurs installing a
factory original equipment part cures the issue.
Low Voltage Disables Hybrid
Vehicle
Question 6
I have been out of the
country for nearly two months. Upon my
return my 2005 Toyota Prius will not start.
Normally when I start the car a ready light turns on in the dash but it
is not turning on. Is there anything I
can do to start the car? R.P., email
Answer 6
The issue might be caused by
low battery voltage in the hybrid battery so consider having the car towed to a
shop equipped to repair it.
There are two
batteries. One is the hybrid battery
pack that is high voltage and could cause serious injury or worse if proper
safety precautions are not followed. It
powers the motors that start the engine and power the electric motor. The other battery is an auxiliary battery
that powers accessories such as the instrument cluster. If either battery lacks power the vehicle may
not start.
If you are not inclined to
have the car towed consider calling a service that can jump the auxiliary
battery. In the engine bay fuse panel is
a connection for the positive jumper cable.
A good ground connection is at the strut tower near the fuse panel. Your service provider will make the proper
connections to jump the battery but even if it is jumped the car may not
start. If so, it’s time to tow it to a
shop.
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. 08/11/2014 ® DR. GIZMO © 1989 - Present
