Q: I have 2002 Buick LeSabre 3800 V6 with about 126,000 miles. When stopped at a stop sign it will die (infrequently so far). It starts up immediately and performs normally again. Your suggestions for what to look for or how to solve?
A: Before it stalls, do you feel a shudder or vibration as the vehicle slows to a stop? It's possible the torque converter clutch is not disengaging when you slow, as it should. The characteristic is very much like stopping a manual transmission vehicle without pushing in (disengaging) the clutch.
If this is the case, the electrically operated torque converter clutch solenoid is sticking, maintaining the differential pressure in the converter housing that keeps the clutch engaged. A transmission additive like Trans-Tune may help, but the ultimate cure is to replace the solenoid, which is accessible after removing the transmission side cover.
The short-term DIY fix is to unplug the electrical connector to the solenoid so that it never engages the converter clutch. The lack of converter clutch function will not harm anything but will cost a bit of fuel economy due to the torque converter slippage. The vehicle will behave just as all automatic transmission cars did prior to development of the torque converter clutch some four decades ago.
Q: I have a 2002 Mercury Sable which has led a protected life. We have followed the maintenance schedule with a local dealer. The car runs nice and smooth for the first few miles when I drive it. Later it makes a very noticeable grinding noise. Shifting into neutral makes no difference — it still sounds awful. My intention is to get the car to my mechanic while the problem is occurring. Do you have any thoughts about what might be going on?
A: My best guess — and it's just a guess — is that one of the ancillary components driven by the serpentine belt is at fault. The alternator, power steering pump, A/C clutch or compressor, idler pulley, tensioner — any of these could be generating the noise. Using a mechanic's stethoscope or even a long wooden or metal rod placed against the body of each of these components while the grinding is occurring would very likely pinpoint the culprit.
I'm also a bit concerned that the noise might be coming from the timing chain or the transmission so I wouldn't hesitate long to get the vehicle to a professional.
Q: I would like to hear your thoughts on why the NHTSA mandates ABS and stability control and then allows manufacturers to equip these cars with tires that defeat their use under normal driving conditions. Rain and snow are certainly normal driving conditions for Minnesota. It isn't only Jaguar that has the problem, but also Mercedes, Audi, BMW and all the sports cars that equip them with these soft V-rated tires with no traction except under perfect conditions. BTW, I did buy new all-season tires and they work fine. Do you know anybody who wants to buy a set of slightly used original equipment tires?
A: Please recognize that no tire can "defeat" ABS, traction and stability control. These electronic systems only activate when they sense a loss of traction. Traction is a function of the tire, not the "nannies."
It's important to recognize that in a very real sense today's motor vehicles and their tires are designed as a package. Carmakers ask tire manufacturers to build tires with specific characteristics for specific models.
Here's my question: Would you have purchased a Jaguar/Mercedes/Audi/BMW if its performance wasn't up to its reputation or your expectations? If you want to drive the car year-round in your climate, keep the OE tires/wheels, mount M&S "all season" tires on another set of wheels and swap the sets seasonally. This is the simplest answer and gives you the best of both worlds.
Tire choice isn't a regulatory issue, it's your issue.