Questions and answers from ‘The Car Doctor’
Q. I have a 2004 Dodge Dakota V6 engine with 4-wheel drive and have an engine light question. Recently my truck had a check engine light come on and the engine code was PO508. So far, we have replaced the IAC (idle air control), TBI (throttle body) and computer. After all of these repairs the truck ran good for one week. On a trip to work the truck started to buck, had a loss of power, accelerator pedal had no response, power fluctuated, although I was able to get truck home. When I returned home, I read the same code PO508. We tested for vacuum leaks and had none. Any ideas where to head on this?
A. Since the repairs solved the problem even if it was for only a week, I believe you were on the right track. I suspect a problem in the wiring to IAC, perhaps a poor ground circuit. The only way to tell is to start reading resistance on each of the circuits. There is a set procedure (trouble-tree) to inspect the components and wiring to find the cause of the code.
Q. Last weekend my 1970
Oldsmobile overheated and had to be towed home. There was no visible sign of leakage from any hoses so I determined it must be a thermostat problem. In replacing the thermostat was relatively straight forward except when putting it back together I could not get the second bolt of the thermostat housing to catch. Without the housing the bolts catch fine but with the housing always one side seems that it won’t catch no matter how much jiggling it will not catch. Also, when taking it apart one bolt had no washer.
A. I would make sure that the housing holes are nice a clear and try swapping the bolts side to side. Also make sure the thermostat is properly seated into the intake housing. There is a cutout for the thermostat ridge to sit down into the manifold. Regarding the washer, I believe the original were a flange style bolt, probably lost over the years. Since you have the housing off, try to pick up a set of thermostat housing bolts (5/1618 x 1-¼) and when reassembling, dab a little RTV silicone on the threads. I would just get everything loose and make sure the thermostat is seated and carefully get both bolts to catch and tighten them evenly to 20foot pounds.
Q. Question for you, because you are the most levelheaded smart person I know on this topic. I just bought a new car (which I do every 15 years, whether I need a new car or not). It’s a 2021 Mustang Mach-E, which you were quite impressed with and so far it is pretty awesome! When it was delivered, it came with two small paint chips, through the clear and color coat. The dealer’s solution is to send me a bottle of chip paint so I can fix it myself. Which they generously report they will not charge me for! Am I being a jerk in expecting a better repair than self-administered chip paint? Is there a better solution, or if I push it, will I only result with the dealer applying said chip paint? I wonder if I am expecting too much of a new car when I paid more than twice the cost of my first house for this new car. Or should the new car come with a complete professional finish? Your thoughts?
A. Touch up paint will never take the place of a professional finish unless you prep the area, apply the color coat, level it out and then add the clear finish. I would expect the dealer to take it back and have their body shop scuff and then touch up the affected area using more than a bottle of touchup paint. The repair should include both color and clear and be not visible in sunlight. You purchased a new car and new cars shouldn’t come with a DIY paint repair. Now if it was a demo or otherwise used car that would be different story. BTW thanks for the compliments.
Q. I have a question that I would appreciate your input on. I recently purchased a Chevrolet C3 Corvette with less than 60,000 (supposedly actual) miles. Although not serious, the car does have some leakage. There is a minor leak at the bell housing section, and it also appears that the power steering may be leaking. I brought the car to a mechanic who services my daily driver, whom I have used for years and whom I trust. His response to the leaks was not to repair them. His point is that older Corvettes are prone to leaks, and that once repaired, the leaks would only reoccur before long. I am seeking a second opinion. Should these leaks be repaired, or left as is and replenish the fluids as need be? Thank you.
A. Your mechanic is right older Corvettes seem to always have some sort of minor leaks and many owners considering the limited amount they drive their cars just live with it. As I see it, there are three options follow your shop’s advice and leave the leaks alone (although they won’t get better by themselves, they may not get worse and monitor fluid levels. Try high mileage oil with the next oil change it can help swell seals and add a power steering sealer and conditioner which could remedy a leaking steering box or pump. Finally, fix what is wrong, the oil leak could be an oil pan gasket, rear main seal, valve cover gaskets or an oil sender unit. If it were my car, I would start with the power steering leak since there are a limited number of components, hoses, pump and power steering box. All of these power steering leaks could go from a small leak to a major leak quickly and certainly worth looking at. The engine oil leak could seep forever, although I would like to narrow down what is wrong. Your repair shop could try a dye in the oil and then trace the leak with a ultraviolet light and then determine the actual problem.
Q. I recently had a problem with my old Ford Explorer not starting. It cranked over but wouldn’t catch. A really friendly guy stopped by and asked if I needed help-yes. He opened the hood and did something, and the car started up. Since then, it has been running perfect. Any ideas?
A. I suspect your Ford had a faulty fuel pump relay and the “friendly-guy” swapped the horn relay with the fuel pump relay.