Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 2 YEAR 2000

by Bob Hagin

Q. My son has a 1997 Dodge Red Ram 1500 with the 5.9 liter Magnum engine and 57,000 miles on it. The engine recently burned a piston. He tows a 20-foot travel trailer several times a year, usually in the summer. He hasn't put any strain on the engine lately, other than normal driving. What would cause this to happen, and is there anything he can do to keep it from happening again?. His mechanic says that Dodge V8 engines are well-known for this. Have you heard that this problem is prevalent? Even though he is past the original warranty, is there anything he can do by contacting the dealer or the Dodge factory? An engine should last a lot more than 57,000 miles, don't you think? J.H. Redlands, CA

A. "Burned" is a catch-all phrase that encompasses a lot of different piston failures. Detonation (the charge in the cylinder exploding all at once) usually results in a hole being blown through the center of the piston. The edges of the piston can be chewed down to the top ring by too much ignition advance, a coolant leak into the chamber, a fuel mixture that's too lean (too much air and not enough fuel in the mixture) and/or a localized vacuum leak that would have the same effect. Spark plugs of the wrong heat range can do it too. Localized engine heating caused by restricted coolant flow in that area or a break-down or lack of engine oil lubrication can cause the piston to seize and score the skirts. If one burned, I'd be suspicious that others will follow. I hope your mechanic examined them all and located the cause. If your son had the correct towing equipment and had the truck serviced as per the factory schedule, he might get help from the factory. Tell him to ask a dealer for an interview with a factory service representative.

Q. I have a 1987 Plymouth with front-wheel drive. The mechanic that changed my oil said that the universal joint boot on the left side had a tear in it and had to be replaced. To make a long story short, he said that he wouldn't just replace the boot and that the whole left wheel assembly had to be replaced at around $380. I trust him to change my oil but not much beyond that. Could you please tell me if it would be OK to just replace the boot for $40 or whatever or is this major surgery? E.S. Seattle, WA

A. Replace the boot or the entire axle is a crap-shoot. If the boot hasn't been ripped long enough to let dirt and road grime get in and grind up the joint, a replacement boot is fine. Pull back the boot and see if the lubricant inside is fairly clean and free from ferrous grindings. A bad universal joint on an axle shaft usually makes a grinding sound when the car is in a very sharp turn. As I see it, you don't really trust your technician and you might be better off getting a second opinion, but be ready to find another source of oil and filter changes regardless of the outcome.

Q. I have a 1994 Mazda B2300 pickup truck with a five-speed transmission and 134,000 miles on it. I usually do my own service work such as changing the oil and filter and also have replaced the spark plugs once. It's now beginning to misfire a bit when the engine is pulling at middle speed. A fellow worker told me that he had the same trouble with his Toyota truck and that his mechanic changed the spark plug wires and the problem went away. How often should spark plug wires be changed or how can you tell if they're not functioning right? J.R. Miami Beach, FL

A. Really bad plug wires will spark and crackle like Christmas tree lights if when you raise the hood in the dark. A quick check of wires that aren't quite that bad is a quick spray of water from the kind of squirt bottle used for window cleaner. Do it especially on the plug ends and if the engine stumbles or dies, replace the plug wires but use quality stuff.