Dr. Gizmo Column

"Dr. Gizmo"
By Phil Arendt

Air Pump Makes Excessive Noise

Question 1
When the 4.6-liter engine is running in my 2004 Land Rover Discovery there is an air pump that is rather loud and when I shut off the engine the pump makes kind of a grinding noise.  I called a dealer about this but they were of no help.  I also went to a local shop where a mechanic identified the noisy pump but he was not sure if the noise is normal or not.

I bought the vehicle six months ago and the noise has been there since the beginning.   What do you think?  D.H.R., email

Answer 1

Congratulations on your recent purchase.  Too bad the previous owner didn’t cure the trouble before you purchased it.

The pump should make little noise.  Since you can hear it in the cabin and it makes grinding noises when the engine is shut off there is an internal problem.  It’s time to replace it.

Body Control Module Gone Wild

Question 2
While driving in my 2007 Chevrolet Silverado 1500 with 87,000 miles the door locks start locking and unlocking, the power windows won’t work, the gauges jump and a warning on the dash for the stability system lights up.  I don’t have any warning that this will happen and when it does if I shut off the truck and start it back up everything is back to normal until the next time the troubles happen.  This might happen four times in a week or I can drive trouble-free for weeks at a time.

I went to my dealership where they replaced a switch for the brake lights but this did not fix the issue.  They told me to come back when the problem is present but so far by the time I get there the issues pass.

I love my truck.  The door locks repeatedly locking and unlocking drives me crazy.  Do you have any suggestions?  L.D.M., email

 

Answer 2

The truck might be possessed.  Consider an exorcism for the truck and an adult beverage for you.  All kidding aside, this sort of trouble might be connected to an issue in the instrument cluster such as a faulty ground connection or perhaps a failing body control module.  Even a loose or corroded pin in the plug on the body control module could cause issues.  Once a priest has done his work consider asking an experienced technician to check out the circuit at the rear of the instrument panel.

 

Technician Possibly Going In Wrong Direction

Question 3
I have a 2001 Honda CR-V with the red ABS light turning on intermittently.  The anti-lock brakes work when I slam on the brakes on slippery roads but the light sometimes turns on. 

I went to a repair shop where they did some tests.  They told me that their test equipment did not find any trouble codes.  They also said that during a test drive their tester lost communication with an ABS module but the light never turned on.  They say the ABS module is working so I should not worry that the system will fail but they don’t know why the light turns on.

Does it make sense to replace the module?  P.N., email

 

Answer 3

Hold off on replacing the module.  There is something fishy going on.  Before spending a bunch of bucks on a module ask your shop technician to check the red light.  Typically, an illuminated red brake light indicates the parking brake is set or the fluid is low in the brake master cylinder.  ABS lights are amber or yellow.  Since your shop does not find anything wrong in the ABS system perhaps they are looking down the wrong branch of the diagnostic tree.

 

Leak Leads To Big Project

Question 4
The oil pan gasket on my 1996 Ford Mustang GT with a 4.6 motor is leaking.  I’m pretty good when it comes to fixing cars so I wanted to replace the gasket.  I took a look under this beast and it looks like the engine has to come out to get the pan off.  I checked on line for another solution but there was no help. 

I really don’t want to remove the motor.  Do I need to take it out to replace the gasket?  L.D., email

Answer 4

Coat the engine with that TV advertised aerosol goo that floats a boat with a screen door in the bottom and there will be no need to yank the engine.  I’m just kidding.

It is not necessary to remove the engine.  Unfortunately, it needs to be raised as far as possible in order to remove the pan and gasket.  It’s also, possible the transmission cover needs removal, too.

Good Luck with your project!

 

Blinkers Intermittently Quit

Question 5
I have a 2004 Ford Expedition with about 115,000 miles.  Before it was out of warranty I had taken my truck into a Ford dealer at least three times but every time I was there they could not find anything wrong since it didn't act up for them.  My blinker has been doing this for some time.

If I’m at a stop light waiting to turn with the blinker on, all of a sudden it stops.  Sometimes I can wiggle the turn handle and it will start again.  At other times it will not.  Some days it works, some days it doesn't.  It can go weeks working and then it acts up.

No one seems to be able to give me an answer.  Do you have any ideas as to what I should be looking for?  J.D., St. Paul, MN

Answer 5

When all else fails power down the driver’s window and use hand signals.  All joking aside I’ll bet most motorists don’t know what hand signals to use in case the turn signals or brake lights fail.  I’m not talking about nasty hand gestures.  I’m referencing hand signals for left, right and stop.  To learn the signals go to the internet and search motorist hand signals.  There are numerous illustrations and videos.

 As for the condition, more than likely since the issue seems to resolve itself when you jiggle the multifunction switch handle, the likely cause is a faulty switch or there is a loose connection at the back of the switch.  To find out, a technician needs to disable the air bags and dig into the steering column to access the switch assembly and connections.  I believe there are three plugs on the switch so a loose connection might be there.  Repair might be as simple as placing more tension on a pin in one of the plugs or the switch might need replacement.

Electrical Power Draw Tied To 4WD

Question 6
The battery in my 2002 Chevrolet Suburban dies after being parked all night.  Since the battery was four years old I replace it but the trouble continued.  I also removed all the fuses to see if I could determine what circuit is causing the battery to die but I had no luck.  Now I am disconnecting the battery every night or in the morning it’s dead.  I found that when I connect the battery I hear a loud clunk sound under the vehicle.

Can you help?   N.K.W., email

Answer 6

Since this appears as a constant electrical draw on the battery the cause of the trouble should be easy to find by an experienced technician.  Also, since you hear a loud clunk under the vehicle when you connect the battery I suspect the noise is caused by the four-wheel-drive transfer case.  It may be engaging.  If so, a technician should consider testing that circuit.  Maybe the control module is faulty and needs replacement.     

 

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 mailto:drgizmo@hotmail.com.  10/07/2013 ® DR. GIZMO © 1989 - Present