Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 32

by Bob Hagin

Q. I have a 1986 motorhome with a Chevy 350 engine. Recently I burned up the engine due to fan belt failure and there was no where to get off the road. The new engine was a new, out of the crate, General Motors replacement. Everything is great except that the engine runs hotter than the old one. The original ran at a quarter or less regardless of my speed. The new one runs at almost half at low speed and climbs to half and slightly higher at near 65 MPH. The air conditioner seems to have little or no effect. The cooling system checks out and the mechanic that did the work has been very good about everything. He has replaced every component that even looked questionable and has even called in a General Motors specialist whose answer was that I was driving too fast. My mechanic seems to think that the engine is acting OK, but I think that he's so puzzled and frustrated that he just wants me to go away. I wish I could but I'm afraid of the problem. B.U. Antioch, CA

A. When an engine gets so hot that it destroys itself, it can take a lot of other things with it. I assume that you've had the radiator rodded out or replaced to make sure its flow is OK and I also assume that the thermostatically controlled cooling fan has also been checked to make sure that its engaging at the right underhood temperature. Sometimes the temperature gauge system itself gets pushed past its limits and reads high from then on. Try a non-electric "bulb" type gauge for a test and you might find that the actual operating temperature is within GM limits. I've never trusted gauges without numbers.

Q. I own a 1987 4WD four cylinder Jeep Cherokee used it now has approximately 262,000 miles. The Jeep has provided outstanding service with not problems on the engine, transmission, rear end or 4WD drive train. I have regularly changed the oil between 3000 and 4000 miles and have replace all the hoses and fan belt every year or so. The timing chain was replaced about 50,000 miles back and the screen or filter in the transmission was replaced about 100,000 miles ago. The body and interior of this Jeep are in outstanding condition. What would you recommend replacing or having checked with this kind of mileage? H.B. Suffolk, VA

A. You must be an easy rider. Nothing last forever but your Jeep is giving it a good try. "Soft" parts like rubber and neoprene seals are affected by ozone in the atmosphere and heat so you might check axle and hub seals and it might be a good idea to run fresh brake fluid through the system. Do a high pressure test the cooling system to check for weak spots. If you haven't had the brakes replaced, check them out since they may be ready for work. Also check the service recommendation chart in your owner's operating manual and see if the various universal and constant velocity joints require periodic lubrication.

Q. We own a '96 Dodge minivan for family transportation so I bought a 1988 Merkur Scorpio as a second car to drive to work. It's something of an unknown brand so I got a good deal on it. I've had it for several months and have had no problems but there is one thing that bothers me. After I fill the gas tank, the gas gauge drops to the 3/4 mark after I go a very short distance. I've taken it to the Mercury dealer who sold the car originally to see if the problem could be fixed but I was told that it was caused by a faulty gauge and that the cure was a replacement of the gauge itself. The price quoted was very high. P.M. Bremerton, WA

A. The German-made Merkur line was an unappreciated Ford stepchild and had several problems that alienated it to Mercury mechanics. Your problem is a mis-calibrated fuel gauge and the only cure is to replace it and the temperature gauge as a unit. Its a long, involved job that nobody looks forward to.