Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 29 YEAR 2000

by Bob Hagin

Q. I wonder if other people have an oil leak problem with their rotary-engined Mazda RX-7. Mine is an '83 with a five-speed manual transmission and 150,000 miles on it. It's been well maintained and has had major components replaced. I know it isn't worth much on a trade and I sure would like to keep it because it fits easily into today's small parking spaces and it's really a fun car to drive. Right now, it isn't getting good gas mileage - tops is near 20 mpg. I'm having a problem finding reliable service for my RX-7. Should I worry about an oil leak and low miles per gallon? The car runs great but I don't want to have something serious as a result of a leak. Is it safe to continue to drive it? I'm a widow with no mechanical expertise. I was told that it would cost as much as a new engine to fix the problem. I want to make an informed decision and not waste money if there's a bigger problem ahead. H.M. Barstow, CA

A. You're right about the RX-7 being fun to drive. It's a true sports car that's as much at home on a race track as it is in urban traffic. It's so popular and fast that several amateur road racing clubs have special races for them with as many as 30 first-series RX-7s making up a single grid. But attrition is catching up with it and there's not many expert and experienced technicians around to keep them running. You don't say how much oil it loses but if its leaking it onto the ground in any great amount, you'd better have it fixed but get a couple of estimates first. You might find a good RX-7 tech near you on the internet. Gasoline and oil are cheaper than an engine but don't ever let it run low on coolant and overheat or the engine will be junk.

Q. In 1980 I purchased a '30 Ford Model A two-door sedan as a retirement project. The only restoration completed at that time was a complete short block overhaul: rebore, new pistons and rings, bearings and new valves. Prior to my retirement in the early '90s, I squirted oil in the cylinders and turned the engine by hand to keep it free. I have, over the years, restored all the running gear and jury-rigged fuel and electrical systems for a body-off test run. The engine started easily but backfired and lacked power. After numerous tinkerings with fuel and timing, a compression test found #1 and #2 cylinders unresponsive on the tester. I squirted oil into the cylinders which produced a response on the meter. Is there a quick-fix to free up the rings without pulling the head and pan and removing the pistons? D.P. Eugene, OR

A. The problem could be stuck valves too. If you have access to compressed air, thread its air supply into a spark plug hole adaptor, then make sure the errant cylinder is on its firing stroke to close the intake and exhaust valves. Put the transmission in low, set the parking brake and turn on the air to a low pressure. Listen at the oil filler tube for the sound of escaping air (sticking rings), then at the exhaust pipe (sticking exhaust valve) and at the carburetor (sticking intake valve). If the problem is the rings, try pouring Liquid Wench or Marvel Mystery oil in the cylinders and let it soak for a week but spin it over with the plugs out before you restart it or it may liquid-lock.

Q. I'm an auto enthusiast and subscribe to all of the major auto magazines like Road & Track and AutoWeek as well as Hot Rod. None of them give any real how-to repair information. I do a lot of auto repairing for friends and neighbors and I'd like to subscribe to a monthly magazine that's more in-depth into the fixing of cars and trucks. D.S. Boston, MA

A. The only pro auto repair magazine I subscribe to is Motor, a Hearst publication. Write them at 645 Stewart Ave., Garden City NY, 11530.