Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 7 YEAR 2000

by Bob Hagin

Q. My 1985-1/2 Ford Escort wagon has 120,000-plus miles on it. It runs great except for one problem: it hiccups. This is what it feels like to me. The RPM needle jumps when this happens. My mechanic has done all that he can do including checking the coil, the distributor and cap, and has replaced the spark plugs and plug wires. He has talked to Ford representatives and I have taken it to a Ford dealership garage. It was all to no avail. The mechanic thinks it is electric but I think that it is in the fuel system. The fuel pump was recently replaced also. F.C. Edenton, NC

A. You don't elaborate on whether the "hiccup" is steady, sporadic, only at high-speed or just at idle. Nevertheless, I think that your mechanic is on the right track. The ideal way to test your car would be to put it on a dynamometer, hook up an oscilloscope and an infrared analyzer, and take it on a simulated "road test." A dynamometer is a big device on which the drive wheels of a vehicle are put between large "rollers." The car is chained to the floor and the vehicle is "driven" at whatever speed the technician desires. When the "hiccup" occurred, the technician could spot an ignition malfunction on the 'scope and/or a fuel abnormality on the analyzer. Dynamometers are becoming fairly common in California due to increasingly stringent pollution control test regulations but they may be hard to find in your area. Ford used to (and may still) have a factory authorized test procedure that calls for replacing a suspected part with one that is known to be OK. After checking all possible electrical ground connections, I'd try another distributor, coil and all the other ignition parts that I could scrounge from a wrecking yard. It won't be easy or cheap - unless you're lucky.

Q. I own a 1995 Chevrolet Impala SS V8 with 55,000 miles. I bought it new and I use this car as a weekend driver, usually on long freeway trips. At about 40,000 miles, the transmission failed. The automatic transmission fluid came out black. I had the transmission repaired at a cost of $1000 and the repair shop said that it was a failure of some "soft" parts. Is there an inherent weakness to this transmission? If so. what can I do to prevent future problems? Also I want to change the spark plugs. The factory plug is a Delco 41-906 at a cost of eight dollars each. Is it necessary to use that particular plug? K.G. Loma Linda, CA

A. I haven't had any letters on the failure of the automatics specifically in Impalas nor have any of the mechanics I've contacted come across chronic problems but that doesn't mean they haven't happened. I searched the internet and while I came up with transmission problems in Jeep Cherokees, BMWs and Land Rovers but nothing showed up on Impalas in particular. Usually the failure of "soft" parts (clutches, bands, etc.) is caused by overheated (blackened) automatic transmission fluid (ATF) which smells burned. You might check out the ATF/coolant intercooler for low flow or consider an add-on auxiliary ATF cooler or even an ATF temp gauge. Late model Impala owners are an enthusiastic and loyal lots and you can contact kindred spirits through the internet. GM owns Delco so draw your own conclusions about the spark plugs.

Q. I bought a '95 Ford Taurus in January of '96 with 18,000 miles on it. The speedometer started fluctuating at 30,000 miles. The dealer replaced it and put a replacement sticker on the door. Now the second one is fluctuating at 30,000 miles. Why is this car having speedometer trouble? I'm the only driver. R.C. Norfolk, VA

A. If the replacement was a new unit, they may have built-in faults. It's possible that the speedometer cable is slightly long and putting pressure on the head. Have an independent speedo shop check it out.