Low-emission vehicle zapping engine’s power until fully warmed

June 20, 2009/Steve Tackett

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

Dear Doctor: I own a 2008 Mazda3 with the 2.3L PZEV engine and a five-speed manual transmission. Ever since I go the car in October of 2007 the engine has run poorly until the operating temperature is reached. It lacks the normal power and responsiveness until the rpm exceed 3,300 at which time there’s a surge of power. Once the normal operating temperature is reached, the engine runs fine. The dealership investigated the symptoms and concluded this is normal. I suspect it is a consequence of the “zero emissions” design. Can you offer any insight into this problem? Gregory
Dear Gregory: Today’s vehicles, especially low emission vehicles, will not run at their full power potential until the engine is at normal operating temperature. This is to further lower emissions during warm up. Some automatic equipped vehicle transmissions will not shift into and out of third gear until the engine reaches 160 degrees. The computer has a preset running program that the vehicle operates during open-loop running conditions. Once the engine is at operating conditions, the computer system goes into closed-loop and the computer monitors all driving conditions and makes all decisions as needed based on all input sensors.
Dear Doctor: We have just purchased a very low-mileage 2000 Lincoln Town Car with 14,400 miles. Once in awhile three of the windows go down and up very slowly, some times not at all. Are the doors grounded through the harness or by the doors themselves? Is there a way to check the wire system in the car? Norman
Dear Norman: Slow window operation is often caused from dried window rubber channels. We always use window channel lubrication from Ford called mini-vent window lube. We also use it on Honda and Toyota window rubber channels. All power-operated window grounds go through the driver’s master power window switch and then to a body ground in the left front inside kick panel. The power and ground would need to be checked at the power window motors by load-testing under operation.
Dear Doctor: I own a 1997 Pontiac Grand Am 2-door SE model. I was informed it needs repairs made to the head gasket and the rack-and-pinion steering. It is my understanding both repairs are costly. The car currently has approximately 91,000 miles. I am experiencing “white” smoke from the tailpipe and losing power steering fluid, which must be refilled every three to four days. Do you think it is worth putting the money into both repairs and/or look for another car? Yvette
Dear Yvette: Head gasket failure can turn into lower end bearing and piston complications, not to mention oxygen sensor and catalytic converter failure from contamination. The white smoke emitting from the tailpipe is what contaminates the converter and oxygen sensors. On the power steering rack-and-pinion replacement, the lower control arms are a problem on this vehicle. What condition are the gas lines and brake lines in? At this point to invest a lot of money may not be in your best interest. If you can afford to step up into a later model car, I would suggest this is the best way to go.
Dear Doctor: I own a 2000 Honda Civic EX coupe. Whenever it rains water seeps into the trunk near the rear passenger side. The weather stripping seems fine. Do you know of any issues that may be causing this problem? Mike
Dear Mike: Water leaks are usually not hard to find. You can try locating the leak by slowly running water from a garden hose at the top of the rear window. Using a flashlight see if you can pinpoint the opening source of the leak. A professional may also use a smoke machine. New seals are available from the dealer.
Dear Doctor: I park my 2004 Volkswagen Golf underneath the train station in the commuter parking lot daily since purchasing the car new. The windshield and the rear window have fine scratches vertically, so it is not from the wipers. I notice this on rainy days when my visibility is poor. Could this be from small parts of concrete that fall from the train platform? Suzanne
Dear Suzanne: Yes, I see a lot of glass scratches on windshields from the cement due to parking under car garages. Depending on how deep the scratches are some glass companies can polish and remove very light surface scratches.

Junior Damato is an ASE-certified Master Technician.

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Copyright, Motor Matters, 2009