Northwest Herald Dr. Gizmo Column Dated July 27, 2012

 "Dr. Gizmo"

By Phil Arendt

Engine Fails To Start, Blame Someone

Question 1

My 2000 Dodge Intrepid with a 2.7-liter engine failed to start. It cranked and cranked and cranked when I turned the ignition but would not start. Finally, the battery died. I called AAA. They jumped the battery and it still would not start so I had it towed to a repair shop.

A mechanic at the repair shop did many tests. He found that the coils were not firing the spark plugs. He said resistors on the some wires for the coil were burnt. He did not know why. He replaced the resistors, coils and spark plugs. Now the car is running just fine.

Could jumping the battery cause the resistors to burn? Did AAA do something wrong? I.N., email

Answer 1

Let’s analyze this issue. The engine would not start even after it cranked and cranked and cranked. You called for road service because the engine would not start and the battery died. The service provider jumped the battery and the engine still would not start resulting in a tow to a repair shop where a technician determined the cause of the trouble and fixed it.

First, the condition was failed ignition coils. Excessive engine cranking killed the battery. This progressed to a jumped battery and tow by an emergency road service provider who transported the vehicle to a repair shop of your choice. A technician repaired the cause of the condition by replacing the coils that were the catalyst for this entire event.

If the road service provider had made a mistake jump starting the battery there would be a lot more to repair than burnt resistors on the coils such as fried computers, exploded battery, shorted wiring, fried relays and much more.

Excessive Pressure Causes Leak

Question 2
I have an oil leak in my 2005 Kia Sorento that is driving me crazy. No one seems to be able to fix it. The car has 136,000 miles and a 3.5-liter engine.

The trouble is oil leaks from plugs at the rear of the engine that have to do with the cam shaft. I have taken the vehicle to two different repair shops where mechanics have replaced the plugs more than once. After new plugs are installed at first there is no oil leaking. After a month I notice drips on my garage floor and then a couple of days later I can be driving along when smoke starts coming out around the hood, the oil light turns on and I have to pull to the side of the road. When this happens I see oil dripping underneath the vehicle and no oil registers on the dipstick.

Mechanics don’t have any explanation as to why this is happening. I’m told all they can do is install new plugs. Can you help? M.G., email

 Answer 2

The plugs of this concern are press-fit. Basically they are smooth round disks that fit tightly into an opening in the cylinder heads. The discs are not threaded like a screw. Under pressure they can slowly slide out of their respective openings and could fall out.

After checking two professional web sites and logic, this condition points to a possible buildup of pressure within the engine that causes the cam plugs to pop out of their bores causing the leak. This might be the result of a blocked positive crankcase ventilation system or possible blockage of the oil ports in the cylinder heads. Repair all depends upon technician findings but returning internal pressure to normal is the key to repairing the cause of the leaks.

Ask your favorite technician to consider internal pressure as the cause of the leaks. Repair might be as simple as replacing the positive crankcase ventilation valve.

Wear Causes Smokey Exhaust

Question 3
Recently, I purchased a 2002 Nissan Altima with a 2.5-liter engine. It looks as good as new. The party that sold the car explained that it had a fairly new engine. The car has 62,000 miles and the engine was replaced when it had 40,000 miles. The seller gave me copies of the repair receipts and all service performed on the car since it was new.

The trouble now is that when I start the car in the morning blue smoke blows out the exhaust pipe. I took the car to a repair shop where they diagnosed the trouble as leaky valve seals. They also told me that the catalytic converters are not working correctly and need replacement.

Is it common for the valve seals to need replacement in this model vehicle? What about the catalytic converters? F.P., email

Answer 3

It is not a common problem but it can happen. Valve seals fail for a variety of reasons but usually it is due to vehicle age and mileage. Premature failure usually is due to an overheated engine, lack of regular preventive maintenance or aggressive driving.

Catalytic converters can fail for a variety of reasons but in your case the reason for failure likely is excessive oil in the exhaust. The converters overheat as they attempt to process oily exhaust causing failure.

The valve seals will need replacement and cylinder head might need complete renewal. Once this is accomplished oil consumption will return to normal. Also, once oil consumption issues are resolved installation of new converters will return the vehicle to normal operation.

Incidentally, the converters likely can be replaced under an emission warranty so consider taking the vehicle to a dealership to have the work completed.

Inoperative Gas Gauge

Question 4
The gas gauge in my 1997 Chevrolet S10 with a 4.3-liter engine and 115,000 miles reads empty all of the time. Is this caused a bad gas gauge or bad float in the gas tank? D.L., email

Answer 4

Maybe neither part is faulty. Besides wiring, the engine control module plays a role. The fuel tank module and dash gauge are connected to the engine control module. Actually the module is a vehicle control module because it controls just about everything in the vehicle. If the dash gauge, fuel tank module and wiring pass tests it is possible there is a fault in the VCM that causes the trouble. If so, it needs replacement.

Tests by an experienced technician will find the cause and lasting cure.

Free Repair Under Recall Policy

Question 5
Occasionally, the ABS light illuminates in my 2002 Mazda Tribute. When this happens the engine feels like it misfires once or the transmission goes into neutral. When the light turns on it might stay on for a few seconds to maybe 20 seconds and then turn off. When the light is off everything returns to normal.

I took the car to a shop where several tests did not find any computer codes and the car never acted up for them. The manager told me to bring the car back when the trouble becomes worse.

Do you have any suggestions? H.M., email

Answer 5

Yes indeed. Your Tribute might be affected by one or two recalls for problems in the antilock brake system. One recall suggests brake fluid from the master cylinder leaks onto the wiring harness to the antilock brake module. Since brake fluid is corrosive it can cause the connectors and insulation to melt. Electrical problems develop that actually could cause a fire.

The other recall is for improper seals on wiring that allows water to enter connections at the ABS module. This causes electrical problems that also could result in fire. Both recalls could cause the warning light to illuminate.

To learn more about the recalls go to my blog at http://wwwdrgizmo89.blogspot.com and click on the link at the top of the page for the National Highway Traffic Safety Administration. When you hit their site enter identification number 07V157000 for one recall and number 12V016000 for the other recall. Also, you can contact your carmaker or dealership to find out if your vehicle is affected by the recalls.

If your vehicle is affected by a recall, repairs usually are free.

 Test Equipment Fails To Communicate With Computer

Question 6
The automatic transmission in my 2004 Chrysler Crossfire sticks in second or third gear and the check engine light is on. I took the vehicle to a repair shop where a mechanic attempted to read codes in the computer but he had trouble. He said his scanner would not communicate with the computer. He said it is likely the computer has a fault, but he is not sure. He said that if he replaces the computer, and the problem is not resolved, he cannot return it to the auto supply store for a refund so I’ll be stuck with it.

The computer module is expensive. Do you think replacing it will fix the trouble? H.T., email

Answer 6

It is rare for an engine control module to fail. Consider taking the vehicle to another independent shop or dealership to have the system tested. Chances are great that the cause of the trouble is an inability of the test equipment to communicate with the car’s computer and not a failed computer. A dealer shop will have equipment to communicate with your car’s computers. It is less likely an independent shop will have the equipment to do all the tests necessary to determine the source of the trouble, but a large well established independent shop usually does.

From your description of the trouble it appears the transmission is stuck in limp mode. It is more likely a problem such as this is caused by a failed range sensor or turbine speed sensor and not a faulty computer.

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  07/23/2012 ® DR. GIZMO © 1989-2012