Questioni took my rx7 to a foreign auto mechanic and he told me the motor is locked up that he couldn't turn it over with a pipe wrench and a bar( the leverage trick). Can rotary motors be turned over this way? Is my motor shot? If so what do you suggest i do to get my car back on the road.
AnswerSo, your car was running one day and then it quit? Was it in storage for a while? Did it make any clattering noises before it died?
If the car was in storage for a while, then my suspicion is that the motor has carbon lock. This means that an apex seal has stuck to some soft carbon on an apex seal. It is possible and inexpensive to fix this problem.
In this case, the locked apex seal needs to be soaked in penetrating oil. Diesel fuel or automatic transmission fluid will work well and both are very affordable. The trick is to get the penetrant to the stuck apex seal.
Penetrant can be applied to the apex seal through the exhaust port after removing the exhaust manifold. On a 79-91 Rx7 this is pretty easy. On a 93-95 Rx7, this is super difficult.
Another way to get penetrant to the apex seal is through the intake port. In this case, the intake manifold should be removed. Again, this is easy on a 79-91 Rx7. It is more difficult on a 93+ model.
It is fine to turn a rotary motor with a wrench, but it is not a very good idea to apply too much force because something could break. An apex seal could break if that's what's stuck.
After the seal has been soaked for a reasonable amount of time (perhaps as long as overnight) try to turn the motor with a ratchet on the front pulley bolt.
Before starting the car, remove the spark plugs and crank the motor for a good 20 seconds. This is to get as much penetrant out of the motor as possible. Install new plugs and try to start the car. It may take quite some time for the car to fire. The car will smoke heavily for as long as 20 minutes after it has started.
