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Friday, November 23, 2012

Northwest Herald Dr. Gizmo Column, November 16, 2012

11/16/2012
 
"Dr. Gizmo"
By Phil Arendt
 
Metal Piece Found On Driveway Clue To Broken Transmission
 
Question 1
I own a 1998 Honda Accord with 189,000 miles. It looks great and has not given me any trouble since I purchased it in 2000 with 15,000 miles.
Yesterday when I was about to leave for work I put the transmission in reverse and it engaged. Then, I heard a clunk and the car moved about two feet and would not move any further. Also, I heard unusual noises I think from the transmission. I left the car in the driveway and a friend drove me to work.
After work I noticed fluid on the ground. I rolled the car back and found a round piece of jagged metal that appears to be aluminum in the puddle. There is a lot of fluid on the ground.
I called my repair shop to discuss what I found but they said that they need to look at the car before they can determine what is wrong and cost of repair. I totally understand that.
The car is in great condition. There is no rust. I have taken great care of it with oil changes every 3,000 miles. I also followed the service schedule in my manual. I believe the transmission needs repair. Do you think it is worth it? M.F., email
Answer 1
What the car is worth to you is a personal matter that only you can determine. I can with reasonable certainty say fixing the car will cost much less than purchasing a new one or even a two or three year old used vehicle.
As for what is wrong, more than likely a shaft or another part broke through the transmission case. If this is verified by your repair shop the transmission needs replacement and not repair. A technician would need to remove all the parts in the transmission and install them in a new case. This is not a proper repair as the parts in the transmission after all have 189,000 miles of wear. Not all of the parts will work once they are removed, and there are many.
More than likely your shop will provide some repair options. One might be to install a low mileage used unit from a salvage yard if one is available. Often when a car is in a rear-end collision the transmission is in good condition. Another option might be to obtain a salvage yard unit and overhaul it before installing it in your car. Yet another option might be to install a remanufactured unit from a reputable company that specializes in remanufacturing transmissions. This might be the best option.
Before making your decision on any of the options, consider the warranty and of course cost.
 
Oil Leak Needs Further Scrutiny
Question 2
My 2007 Audi A4 leaks oil. It has a 4-cylinder engine. At first I noticed a few drips on my garage floor but after a month there is a large oily stain on the floor about two feet in diameter.
I examined the engine and discovered a leak at the rear of the valve cover. In the past I have replaced valve cover gaskets but it’s been many years. I’m not afraid to do the work and I have lots of tools so I think I can replace this gasket.
Is there anything I should watch out for? D.J., email
Answer 2
Watch Out! A meteor might fall from the heavens and crush your car. On second thought a meteor smashing your car might be worth big bucks. Anyway, removing the valve cover to replace a leaky seal is not brain surgery. Since you have done it the past this should be a task you can handle. However, before you move forward with the repair, thoroughly clean the area of the leak. After it is clean wait a day or two to verify the source of the leak. The cylinder head might be leaking instead of the valve cover so make sure it is the valve cover.
If the head is leaking, let a pro tackle the work.
 
Troubled Transmission Fries Control Module
Question 3
The transmission in my 1998 Dodge Ram 2500 truck with a diesel engine began to shift erratically and the check engine light turned on in the dash. I checked the transmission fluid and it’s full. I took it to an auto supply store where an employee tested the computer. He found code 1693. He said that likely the electronic module needs replacing.
Is this something I can do? H.T., email
Answer 3
Sure you might be able to swap the module but the truck won’t operate correctly unless you have the equipment to program it. Additionally, it is possible something failed in the transmission resulting in a failure of the control module.
The transmission has electronics within the unit. If an electrical part shorted the event could damage the electronic control module resulting in replacement of both units. Better leave this job to a specialist.
 
Oil Pressure Adjusts Valves
Question 4
The check engine light turned on in my 2007 Cadillac Escalade. My repair shop did some tests and found a code that indicated a problem in the timing of the camshaft. They explained that oil pressure somehow controls the timing of the camshaft gears and that for some reason it is low causing an issue with how the camshaft works. They said that to find out the cause they must at the very least remove the oil pan to check the oil pump. I did not authorize the work.
In the meantime they changed the oil and poured in heavy oil to compensate for low oil pressure. They said the engine might need an overhaul but they won’t know for sure until they look inside it.
My vehicle has 110,000 miles. It has a large 6-liter V-8 engine. I have owned it since it was new. I have followed the recommended services in my owner’s book including oil changes when the oil monitor says it is due.
I’m upset over the fact my engine might need an overhaul or replacement as suggested by my garage. Does what my shop says make sense to you? D.R., email
Answer 4
Oil pressure does indeed have an effect on the movement of the camshaft to synchronize the opening and closing of the valves with the up and down motion of the pistons. When oil pressure is not within specifications the hydraulic pressure necessary to time the movement of the camshaft is off. As a result, the valves and pistons are not within timing specifications and the engine does not perform as designed.
Apparently, your shop has tested the oil pressure and determined it is low. This might be caused by excessive engine bearing wear, heavy deposits of sludge in ports in which oil flows or excessive wear of the oil pump or heavy deposits of sludge in the screen on the oil pump.
Since it appears that you rely on the oil monitor to alert you to change the oil this might not occur for a year depending upon driving habits. If this is true, it is possible deposits in the engine have caused this issue. Your next step is to get a second opinion from another repair shop but more than likely they will suggest an internal examine of the engine which will require removing the oil pan. Repair indeed might be to replace the engine.
 
Transmission Fails After Panic Stop
Question 5
I was traveling on the highway in my 2006 Mercedes-Benz ML500 and had to make a hard sudden stop at 65 mph to avoid a collision that had occurred between three cars in front of me. My car was not involved in any way. Once the tangled mess in front of me was cleared the transmission in my car would not engage. All I heard was a buzzing sound under the car.
I had it towed to the nearest repair shop where a technician found no physical damage. The wiring and fluid appeared normal but he did hear buzzing sounds form inside the transmission. He did some tests but his equipment could not communicate with the module that controls the transmission. He says there is damage inside that causes the buzzing sound, but his shop does not repair transmissions.
The car was towed to a dealership for further diagnosis. As of yet I have not heard from them. What do you think happened? Could a sudden stop cause a transmission to fail? What do you think is wrong? R., email
Answer 5
Thankfully you avoided a collision.
More than likely the troubled transmission is coincidence. Sudden stops do not cause transmission failure, but apparently inertia caused an excessively worn part to go where it shouldn’t.
Buzzing sounds are a clue that there might be a failed hydraulic pump or torque converter. A technician will likely remove the transmission pan to check for metal fragments. If he finds numerous ferrous fragments, the transmission needs major repair or replacement.
 
Water Leak Leads To Car and Dealership Problems
Question 6
The battery in my 2005 Ford Mustang GT was going dead every couple of days. I took it to a shop where a technician found the headlights were not turning off properly. He also found water in a junction box on the passenger side. He found a water leak and repaired it. He also replaced the carpet and junction box.
After the work the power door locks did not work. He did many tests and concluded that the box that he purchased from a dealership was not proper or needs reprogramming but the dealer says it does not need programming as it just needs to be plugged in. They insist he did something to cause the trouble. Now he is at a loss.
I need the car so I’m driving it until I have time to leave it with him. Do you have any suggestions? L.T., email
Answer 6
Put your pony out to pasture. All kidding aside, ask your technician to call another dealership. It’s likely the module he purchased needs reprogramming despite what he was told by the selling dealer parts department. Also, he should consider giving authorization to another dealership to do the reprogramming work if he does not have the equipment to complete the task.
 
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.  11/16/2012 ® DR. GIZMO © 1989-2012

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