engine stopped cranking
 

Alright, so I have had minimal problems with the car since my last post a few months ago, it has been running great. However today I drove it home, turned it off for maybe 10-15 minutes while I got ready for work. When I went out to start it again, I turned the key and it rotated maybe 3-4 times before it came to a grinding hault. I tried it again and the starter engages (thumps) but does not turn the motor. I then proceeded to push it up an incline and let it roll back down and pop the clutch, nothing. The wheels only locked up. I don't see what could possibly cause a seemingly healthy rotary engine to all of a sudden seize up like that. Checked oil and Coolant and they were still good (I had actually topped it off with oil when I filled up that morning). The car hasn't overheated, good oil pressure, and I am very meticulous about checking my gauges every few minutes. Does anyone have any idea on where to start tearing into this thing?

Almost forgot. 1991 Mazda RX7 S5 Convertible. Completely stock except for some snazzy LED headlights.

So you cant rotate the engine by hand?

Not by the usual way of pulling on the belt. I will probably pull the fan off tomorrow and try moving it with a breaker bar

If you cant spin it by hand it could be acouple things, could have spun a bearing in the stationary gears, carbon lock, lost a apex seal, whats was the milage?

About 157,500

I'm almost certain it's on its second or third engine.

If you can put a 18mm socket and turn it over with alot of force its mostlikly a spun bearing, rock the motor back and forth if it goes a little bit and see if its just carbon build up

If it's carbon lock it will not move at all correct?

Yes and no, you should beable to rock the engine, my front stationary gear failed and i could turn it over with a breaker bar but not by hand

This is scary. I will be tearing into it at a shop tomorrow. I will try all these methods and a few others I saw on Atkins rotary. I will keep you guys posted.

A bad pilot bearing could do the same thing, did you have any strange noises when driving it last?

Was it hard shifting gears? Clutch pedal feel funky?

Yes the pilot bearing is bad. It has made noise for a while now. Would a bad pilot bearing keep the engine from cranking even if the clutch was pushed in?

Yes. It could seize the trans input shaft to the eccentric shaft. You can confirm this by raising the rear wheels off the ground with jack stands and start it.

It rolls in neutral and when the clutch is pushed in, but I will try this. Because any theory are good theory at this point. thank you. :)

It will, because in neutral the trans is disengaged from the input shaft

May as well do a whole clutch kit since you'll have the trans out anyways

What about in hear with the clutch in?

*gear

Its possible the clutch went with the input bearing or the throwout bearing is seized also. If you jack the rear end up and try starting it and the wheels turn with the engine rolling, you know its a clutch/trans issue

You should be able to turn the engine by hand with the trans in neutral. I seriously doubt the clutch or transmission is keeping the engine from turning.

Is there any possible way for the starter to jam itself into the flywheel? Because I was only cranking it to start when it seized, and it made a nasty grinding noise when it seized.

pull off the starter and find out, there are two bolts holding it to the bell housing so it shouldnt take long :)

That is first thing on the list tomorrow. I will be towing it to my school's shop though, so that I can use the lift. :)

Ahhh the use of a lift, i'd love that access besides a creeper cart lol

That's all I have at my home. XD

I have overhauled piston engines with just a jack, some jack stands and a creeper (and a lot of different of hand tools). However, this car is low and I now have access to the technology! Plus paying that much money for insurance with free towing makes me want to use it every once in a while. :)

it's your led headlights. engine done went and had a snazz attack