Talking Cars: Any ol’ car can go straight

Junior Damato

QUESTION: I own a 2005 Cadillac STS, 3.6L V6 with 75,000 miles. I have been the owner for three years and purchased it certified-used with 14k miles. Although the 22-23 mpg average I am getting is acceptable (two-thirds of driving is non-city), I would like your take on these performance chip products. What are the pitfalls? Also, the shop (dealer) has replaced the timing chains (62,000) in this engine. I have always felt that the shifting in this drive train has never been consistently smooth since I bought it. The dealer states that all updates are present and that the car is operating correctly. Thank you for your insight. I look forward to your weekly articles.

ANSWER: I am a believer in performance upgrades for the person who wants as much as they can get from their vehicle. You should not notice any loss of gas mileage under normal driving conditions. Most performance upgrade computer chips or reprogramming require the use of premium gas. Fresh air intake and low restriction exhaust will also increase performance.

QUESTION: I noticed on my 2005 Cadillac SRX that to go in a straight line, my steering wheel has been at the 8 o’clock and 2 o’clock position for a while. I recently bought four new tires and had them balanced, but noticed the steering wheel was still at the same position. Last week I brought my car into the Cadillac dealership to have a wheel alignment. When I drove out of the dealership, I noticed that again to hold a straight driving line, my steering wheel was at about the 8 and 2 o’clock position. I took it right back to the dealership and they told me it was aligned within specs and there was nothing else they could do. Is there a way of correcting this so the steering wheel is at the 9 and 3 o’clock position and the wheels are aligned?  

ANSWER: So we all can understand what the dealer service advisor said, there is nothing more we can do. That must mean that the dealer does not have anyone that can properly align the steering wheel, or your car has a defect. Time to go to another shop that can properly align the car and straighten the steering wheel. I would get the car aligned and bring the bill to the dealer and ask for a refund. This is unheard of. This is the old way some of American dealers were doing business. Happy to say the majority of American dealers do take care of car owners.

QUESTION: I own a 2004 Chevy Tahoe Z71 with the 8100 Vortec engine. The vehicle has been well maintained and has 55,000 miles on it. Recently I brought it to the dealership after it began making a loud rapping sound coming from the top part of the engine. The dealership diagnosed the noise as coming from the lifters. To repair it would be quite expensive. Do you think the motor could seize on me if I ignore the problem? Are there cheaper alternatives to a major engine repair?

ANSWER: At 55,000 miles with the large 8.1 liter v/8, lifter failure is rare. The engine should not fail or seize. What I would like is a second opinion. You can also upgrade to full synthetic oil, which reduces engine moving part friction. To replace the noisy lifter is not a major experience if needed. I would recommend the repair if you plan to keep the vehicle.

QUESTION: I am switching to a high-mileage synthetic blend 5-30 oil in my 1999 F-150 with about 145,000 miles of great service. When I need to add a quart of oil between changes can I safely use regular 5-30 oil? I have a few quarts of regular that I hate to waste if they can be used in a limited amount with the synthetic blend. Thank you for your time and answer.

ANSWER: The old rule of thought about mixing oil is old school. Adding a different brand, viscosity, aka weight, type regular, synthetic or synthetic blend will not cause any harm on vehicles with high mileage 70,000 and more. On vehicles still under factory warranty, you do to have to stay with the factory recommendation for oil viscosity and type. High mileage oil does have a different makeup with an additive package for engines with wear. I do not recommend the use of high mileage oil on engines under 70,000 miles unless the engine has internal problems such as leaks and burns oil.

Junior Damato writes weekly about cars. You can send questions to him care of the Old Colony Memorial, 182 Standish Ave., Plymouth, MA 02360.