By Phil Arendt
Odor Develops After Oil Change
Question 1Right after the first oil change in my new 2011 Chevrolet Cruse there has been a hot oil odor. Our dealer has not found any oil leaks but they have replaced all the seals and the thermostat housing. They also did some recall work.
To this day the hot oil odor
continues. I called my local Chevrolet
district office. They said that I should
trust my dealer to find the problem. Do
you have any idea what causes the odor?
K.W., Hudson, Wis.
Answer 1
For an odor such as this to
persist there must be an oil leak. Since
there are no leaks perhaps the odor is from the heating, ventilation and air
conditioning system. Maybe the heater
and evaporator are in the need disinfecting as these units sometimes develop
microbes that can cause an odor.
Faulty Sensor Causes
Multiple Symptoms
Question 2I have a 1998 Dodge Ram 1500 with a 5.9-liter engine, 5-speed transmission and 130,000 miles. It’s my work truck and it’s in great condition. I follow the factory maintenance schedule and change the oil and filter every 2,000 to 2,500 miles.
About a year ago I had the
intake manifold and throttle body gaskets replaced due to leaks. Until recently it’s been running great. Right now the check engine light is on and the
engine runs rough, hesitates and sometimes it stalls. This only happens after I have driven for a
while, stopped for a short time and then restart. This is an intermittent problem as it does
not occur after each stop.
I tried to fix the trouble
by installing new spark plugs and wires.
It runs a little better but the main issue is not resolvedI went to a repair shop. They did some tests and found the fuel pump is working fine, the engine is running to specifications and all the sensor and computers are working fine. The only thing that is questionable is an oxygen sensor does not respond as quickly as it should. The technician is not sure if replacing it will fix the intermittent trouble.
Do you know what’s wrong or
have any suggestions? D.B., email
Answer 2
The possibilities are endless but considering age and mileage it’s likely a poor connection is causing the trouble. A faulty ground or corroded connection in a plug might be the cause. Also, suspicion points toward a problem in the lazy oxygen sensor. There is more than one oxygen sensor in the system but your technician knows which sensor seems to have a problem. It might be the one that is causing all of your concerns. If so, replacement will return your truck to full duty.
Headlights Stall Engine
Question 3When I turn on the headlights in my 2000 Mercury Grand Marquis the 4.6-liter engine stalls. I’m pretty handy when it comes to fixing cars so I checked the fuel pump and found it did not meet pressure specifications. It only produced 10 pounds. I replaced it. With the new pump installed pressure was back to 35 pounds per square inch. Regardless, when I turn on the headlights the pressure drops to zero and the engine stalls.
Have you ever heard of
anything like this before? C.R.T., email
Answer 3
The auto repair business is
ever challenging, changing and change is constant. This symptom is certainly unusual but likely
due to a poor ground connection. It’s
time to study electrical diagrams to find the relationship between the fuel
pump and headlamp circuit. It’s likely
there is a common ground connection.
It’s also possible a poor ground connection in one circuit creates a
feedback in another circuit.
Additionally, sometimes low
voltage due to a faulty battery or alternator will cause trouble such as you
describe. Tests might find this is the
cause.
Consider checking your local
library as it might offer a free online repair manual or subscribe to one of
the many online manuals to obtain diagrams to troubleshoot the circuits.Simple Fix Might Cure High Oil Consumption Trouble
Question 4
I have a 2002 Subaru Forester with 92,000 miles, a 2.5-liter engine and automatic transmission. It uses two quarts of oil every 500 miles. The engine does not leak a drop of oil and I don’t see smoke from the exhaust.
The engine runs great. What would cause this problem? H.A., email
Answer 4
The oil is not evaporating. It is being burnt by the engine. You don’t see smoke from the exhaust due to
the action of the catalytic converters in the exhaust system.
If you are mechanically
inclined, to fix the trouble might be simple.
Sometimes a condition such as this is caused by a faulty or clogged
positive crankcase ventilation valve. Consider
replacing it. Also, check the hose for
blockage. You may need to replace the
hose too.
If the PCV system is not the
problem it’s time to visit a repair shop to have a pro perform tests on the
engine starting with an oil consumption test followed by a cylinder leak down
test, compression test, cylinder balance test and vacuum test. These tests will determine where trouble is
inside the engine.
No Starts And Stalling Have
Common Fault
Question 5I own a 1999 Cadillac Seville with 125,000 miles. It is beautiful inside and out, but it has two problems. When the transmission is in Park when I turn the key to start the starter is dead. When this happens if I shift into Neutral and turn the key the engine usually starts. If not, I have to shift back into Park and into Neutral again.
The second problem is almost
every time I drive. The engine stalls as
if the ignition was turned off. When
this happens I roll to a complete stop and attempt to start the engine. It starts again as if nothing happened.
I went to a dealer shop and
independent shop to have these issues repaired.
The dealer charged $650 for a tune-up and two sensors. This did nothing to resolve the issues. The independent shop charged $75 to look over
the car but could not find the trouble.
They suggested the ignition switch might be the problem.
It would be ashamed to
discard this car. Can you help? E.L.D., Webster, Wis.
Answer 5
It is possible the ignition
switch is the root of the trouble. More
testing is necessary. Definitely a
technician needs to experience the trouble.
Consider leaving the vehicle with the shop of your choice so a
technician can see first-hand how the car reacts while test equipment is
connected to it. He or she must drive
the vehicle and try several starts under cold and hot engine temperature
conditions.
Additionally, test drives
must be completed under conditions similar to when you experience the
stalling. It is important for you to provide
as much information to shop personnel about driving conditions so they can
recreate conditions that induce the problem.
Engine temperature, speed, traffic and weather conditions all contribute
to how a vehicle behaves.
Parts Replacement Plan Does
Not Fix Stalling Problem
Question 6Intermittently, my 2006 BMW 325i stalls. I’ve already dumped a bunch of money into fixing this trouble to no avail. At an idle the engine will attempt to stall but if I hit the gas at the right moment it comes back to life as though nothing happened. After this the car drives normally until the next time it happens. It only occurs at a stop and never tries to cut out while driving.
The check engine light has
never turned on. My repair shop has
tested computers and has received random codes but even the codes are
intermittent. They seem to be guessing
as to what causes the trouble. They have
replaced a battery sensor, two water pumps, fuel pump, alternator and much
more. The problem persists.
The car is in great
shape. It only has 36,000 miles. I don’t want to get rid of it. Do you have any suggestions? H.N., email
Answer 6
There is hope, but you might
consider donating the vehicle to the military for target practice. All kidding aside, apparently you have spent
a ton of cash and the trouble evades repair.
It is also apparent your shop is throwing parts in the vehicle in hope
of curing the trouble without any success.
Don’t despair.
It’s time for a technician
to look into poor wiring connections.
There may be a loose ground connection.
Perhaps a pin in a plug is loose.
Maybe corrosion is affecting terminals in a plug but at this point
throwing parts at the trouble just does not make sense.
At this time consider taking
the vehicle to a different shop if you desire a fresh set of ideas but
certainly the parts replacement plan is not the proper course of action to this
repair.
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. 05/20/2013 ® DR. GIZMO © 1989 - Present
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