Hi - My daughter has fallen in love with an '87 RX-7, and wants to buy it from a friend. I know very little about them (other than they have rotary engines) - nor do I know very much about this car (haven't seen it yet). I was curious about reliability, how often they need service, cost of parts, etc. She currently has a '94 Grand Am, and it's pretty simple to work on, and pretty cheap. Any comments? Thanks - Brian
If it is a stick, make sure the clutch is in good shape. If you know how to drive one, they can last coupla hundred thousand miles but it is not at all unusual to see one pretty much gone at 45K or so. The manual transmission is pretty robust, which is good news as some of the rebuilders hate RX-7 transmissions and refuse to touch them. If a manual, think about filling with the Redline MTL, it lasts much longer.
Also make sure it can pass smog. It can get expensive to fix if any of the major things are busted. The catalysts are expensive and should *never* be replaced with any cheap aftermarket unit, they simply won't last. Spend the bucks for a premium brand if needed.
If the owner(s) took good care of the oil [don't use synth], the engine itself can easily run 200-300K miles. Or it can blow a seal in less than 50K. It *is* cheaper to replace the entire engine, available as a rebuild from Mazda, than a normal piston engine. The engine is designed to burn oil. It injects about half a cubic centimeter every [mumble] so often to keep the rotor seals lubed. If it *doesn't* burn about a quart every 1500-2000 miles, that is not good. Some burn as much as a quart every 700-1000 miles. I have 280K miles on an '85 and it still only burns a quart about every 2K miles.
Driving it hard can't hurt the engine, I've been using the rev warning for decades as a shift indicator. The rotor itself is only turning at 1/3 of the tachometer speed, so 7000 rpm is essentially nothing--other than big grins.
If it has been well cared for, it can be astonishingly reliable. Very little torque coming off a dead stop, but once moving, it can cruise at very high speeds for hours and hours with absolutely no extra wear.
Many towns have independent rotary specialty shops. I won't let a dealer touch mine.
Lots of info here:
There is a newsgroup for rotary engined cars, which is essentially an RX-7 group.
Mazda does not recommend synthetic lubricants for the rotaries. There is probably a reason but I'm not sure what it is.
The rotary engines inject a small amount of oil into the intake using oil injectors. This is the only way to lubricate the combusion-side of the seals. Synthetic oil does not burn nicely and can leave a residue, so that's why regular oil is absolutely a must. Burning a bit of oil in rotaries is very normal, burning none is not normal. Change the oil regularly, drive easy when the engine is cold, hard when the engine is warm and the engine is last. Works for me,
230K Km > Thanks for all the info. Just curious - why not synthetic oil? I don't useNeat info.
I had been waiting to recognize a vehicle with a rotary engine so I could listen to how it sounded when it's accelerating. I saw a car at the stoplight about a month ago and it said RX-7 on it. Neat lookin' car!
It didn't even sound that different really. I didn't get a very long listen, but it didn't seem any different from a piston engine.
Sounds like they're pretty danged reliable!
If given moderate care, yes. Impossible to overrev the thing practically. I have in excess of 230K miles on a 12a and still routinely shift it at the warning buzzer.
The really old rx7 engine had a unique sound, thank goodness they fixed the "whoopee cushion" effect on the smogged models and newer.
Oh yes. There is one little feature of the rotary that is not so endearing. I have a Jeep Grand Cherokee that gets better gas mileage both in town and on the open highway than the RX-7. Granted the RX-7 can get way more tickets, easily reaching 125 or so...safely.
The rotary has the horsepower characteristics of a small high rpm v8. No torque at low speed, lotsa horsepower when running at high rpm. It may only be 62 cubic inches, but that is an effective displacement of 186 cubes due to the multiple combustion cycles.
| | If given moderate care, yes. Impossible to overrev the | thing practically. I have in excess of 230K miles on a | 12a and still routinely shift it at the warning buzzer.
Buzzer goes off at 6500, redline is 7K. You can push them to 7500 regularly, but 8000 will cost you an apex seal now and then.
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