I own a 1986 RX-7, with only 36,000 miles. It had sat unstarted for 2 years in my garage, when I noticed a coolant leak on floor this summer. Recharged the battery and the engine turned over with no problem, but wouldn't start. Had to have it towed to a foreign car mechanic who was able to get it started, but white smoke poured out of the exhaust. He pulled a plug and scoped the interior of the front rotary cylinder, noticing a dark stain he determined to be caused by a coolant leak. I was told the engine must be rebuilt, and threw out a $3-4K price to do it.

I don't know a lot about rotary engines, and I'm not convinced this mechanic did either, but I do know that the last time I took this car out on the road, it ran beautifully, with no smoke. I can believe that sitting for a couple years could take it's toll on the gaskets, but this mechanic seems to think I have a cracked block or that the aluminum casting of the motor has been eaten away by the coolant.

Even if the front cylinder has been damaged, I thought the genius of the rotary engine was that the damaged cylinder module could be swapped out for a new one, without a total overhaul of the entire engine.

Sorry for the long-winded post, but even though I'm a novice at this, what I'm hearing from the mechanic goes against what little I know about the car. Some good information would be greatly appreciated.

Thanks,
Sam

 

i would take it to a place that specialises in rotary engines and have them take a look at it. if you dont trust the mechanic knows a lot about rotary engines why pay him to work on your car?

 

Like RX7nubie says, find a rotary shop and have them get the engine running. Run the car for awhile and the smoke may eventually dissipate if it was just burning off the fuel-oil dumped into the engine during the attempts to get it started. Then have the shop do a proper compression test on the engine to determine its health.

Just a helpful suggestion: Read more about rotary engines since it is pretty obvious by your statement that you need to be educated on the topic. This is not a criticism, just some advice. If you are going to get involved in rotary-engined cars, you've got to understand the inner workings of the engine. There are many books that provide details of rotary engines, and this and other forums are a good place to read and learn.

There is no "cylinder" in a rotary engine, for example. There are rotors and rotor housings. If there is a problem with either rotor/housing the engine requires a complete rebuild. Rebuilds can be done for anywhere from $1,500.00 on up depending on who does the rebuild and on the condition of existing components.

BTW, welcome to the forum!

 

Run a search on "alumaseal".

 

It's unfortunate you started it after letting it sit for two years. You have probably done significant damage to the fuel system and perhaps physical damage to the sealing surfaces inside the engine. http://www.aaroncake.net/rx-7/unstore.htm

A coolant leak could be from anywhere, and an external coolant leak does not mean the engine needs to be rebuilt. Is the white smoke more like steam and sweet smelling? Does coolant magically disappear with no external leak?

The smoke could be a number of things. An injector locked open will cause the same issue, and there would have been a lot of moisture in the exhaust system after sitting.

Scoping the inside of the engine won't tell you much unless the coolant leak is actually large enough to be visible. If this person has a scope, they should also pressurize the cooling system with a pressure tester and leave the car overnight. Then scope in the morning and check for coolant.