mazda rx-7 NON Turbo engine seals...need replacing?

Question

is this a hard job and $$ to have a shop do it.. I am somewhat mechanically inclined..what does it entail??

Answer 1

It would involve disassembling the block into the 6 main parts (2 rotor housings, 3 side plates, and the eccentric shaft) and removing the rotors, then changing the seals. If you are comfortable with removing the engine and you can keep track of the parts you can try it, but it really is a job best left to experts. There is a really good site with videos on many parts of the rotary that might help here: http://www.rebuildingrotaryengines.com/videos/all

Answer 2

This is a complex job, best left to the professional mechanic. Usually the seals that start leaking on this engine are along the top of the engine above the spark plugs. The only way to access these seals (little "O" rings) is a complete engine tear down. Just pulling the engine on this model is a 14 hr job, if I remember correctly. A seal kit is not real expensive, but you may find other problems once the engine is opened up.

Answer 3

First and foremost, what makes you think you need 'engine seals' replaced? does it have some sort of issue which you've narrowed down to be some sort of engine seal, or did you assume that because it's a rotary and its not running properly that "it must be one'o dem' seals in that little rotaspinner motor, shoot!" I've seen MANY rotaries with 'blown seals' running after ten minutes of an experienced rotary mechanic's work. there are A LOT of things that can cause it to not run, but every "experts" conclusion is always 'must be the seals in that engine, they always go bad'.

Second of all, there are lots of different seals in a rotary engine - apex seals, side seals, corner seals, coolant seals (inner and outer), oil control rings (again, inner and outer), front main seal, rear main seal, tension bolt seals, and probably a few more im forgetting off the top of my head. each will have their own symptoms.

a blown inner coolant seal will act pretty much the same as a blown headgasket on a piston engine. the engine will run hot, could pour white smoke out the exhaust, or pressurize the coolant system and spit coolant everywhere out of the overflow tank.

a blown oil control ring will smoke light blue smoke out of the exhaust, and possibly the engine will run hot.

a blown apex seal will give you no compression on the two rotor faces it shares a corner with. so one blown apex seal will give you a compression test reading of maybe 0-0-80, 0-0-80 on one rotor. so basically, the car wont run or MIGHT run one rotor. in addition, the apex seal will wipe out a rotor and housing when it blows, making them useless in a rebuild.

side seals and corner seals dont usually break, but they can stick and cause low compression readings. usually running the engine for a bit and running it a little hard will break them loose and they will seal properly again.

If any of the above internal engine seals are blown, you have a blown engine and need a rebuild. its that simple. blown internals seals arent just replaceable like an intake manifold gasket, you have to do a full tear down and rebuild. This will cost around 700-1000 dollars in parts alone.

If your decide you want to rebuild the engine, its gotta come out. The rebuild process is a big long process for a first timer. dont expect to do this in one night or even a week. I dont know where this '14 hours of labor' crap comes from, because ive pulled plenty a rotary engine in less than two hours. you can probably do it in four. One day we (me and a friend) even pulled an engine, rebuilt it, installed it, and had it running in one evening (from 3pm to about 3 am, but hey its a lot of work!).

Once the engine is out, you gotta tear it apart, you will most likely need an impact gun to get the front main nut and the flywheel nut off (or some long bars, a big wrench, and creativity). Once you take the engine all apart, the easiest way to rebuild it is to re-use all of your hard seals except apex seals (get new ones), and get new gaskets and oil control rings. for your hard seals, get all new springs. The process of rebuilding is a bit of a *****, and takes a while. 90% of the rebuild process is spent CLEANING EVERYTHING VERY THOROUGHLY! If you determine that all of your housings and irons along with the rotors are re-usable, you can clean the crap out of them, clean your hard seals, get new gaskets and springs, and put the engine together in about three hours.

its not the easiest job in the world, but if you take time to research what you're doing, you can probably do it yourself. another option is to just buy another used engine and put it in. i wrote a lot of crap i realized, but good luck!

Answer 4

Super hard job. Even Mazda techs turn these jobs away because it isn't worth the trouble unless it is a hobby. Find a professional rotary expert and ship your engine to him. I don't doubt that you are able to do the job - given enough time, but there are a wicked number of parts that must go in order and you need a super clean work surface and experience. You have to know rotaries to be able to diagnose them properly and troubleshoot any mistakes you may make during the rebuild. I would practice on a junk 13b if I were you just so you can at least get your feet wet.

Answer 5

Leave apex seal replacement to the experts. It is a major job that requires complete overhaul of the engine. It is also a VERY labor intensive (= expensive) operation. Make sure it won't cost more that the car is worth before you sink a bundle on repairs.

Answer 6

main seals?

The engine must be removed split from the trans and tore apart

The seals are on the bottom side on the crank