Hello I have a 79' LE RX-7

Ive owned her less then 1/2yr and she has been nothing but trouble, Ive replaced a few parts with little luck getting a smooth ride. I just took her to a shop and the tell me she needs to either rebuild/machine the rotor housing to stop the major leak or drop in a new engine. The engine only has 90,000 miles but did sit for a few years here and there. My problem is i live noware near any one or shop that will work on the major of a fix so any advice on what you guys would do?

Thanks much, Anthony

 

You forgot to say why it need a rebuild.

Is it an oil leak, water leak. compression leak

If the shop won't do a rebuild. how much do they know about a rotary.

We need detail, so type your fingers off

 

Agreed. And never take your rotary to a mechanic. 9 times out of 10 they'll tell you the motor is bad, just because they haven't got a clue...

So give us the details, you might not even need a motor at all.



.

 

If you're lucky you might be able to get away with just a reseal depending on weather the engine was abused, etc. More info is helpful as already mentioned.

The cost of a rebuild depends on how "all-out" you want to go. Rebuild "kits" are popular which typically include all the necessary seals and gaskets along with the apex seals, springs, corner seals, springs, plugs, oil control seals, etc. There are rotary shops online that sell rebuilt engines so all you have to do is pull yours out and put in a rebuilt engine. Good luck

 

90,000 miles is not a great lot for modern engines. For engines (all brands, not just rotaries) built in 1970's, though, whether or not it's "a lot" depends entirely on the care it had.

But yeah, details, photos, any additional info will help people here help you decide what to do.

 

Hell, my last motor lived to see 213,000 miles. Of course I drove it like a little old lady on her way to church every day (NOT)...

Seriously though, take a flooded rotary to a mechanic and the first thing he'll do is a compression check. The next thing he'll do is tell you to come up with 4500 bucks for a replacement. I, on the other hand, would tell you to spend 8 bucks on a can of Seafoam and have you running in under three minutes....

 

Well, your mileage MAY vary, of course... hahahahaha.

I've heard of motors going that long... but I lost my first one only a year or so after I bought the car. I don't think the previous owner was as careful about oil and such as he should have been. Certainly did nothing to explain rotary care to me when i bought it. i I hadn't read the owner's manual, I'd've been hosed quickly.

Average so far over the lifetime of the car has been about 10 years per motor.

 

Small correction to that statement... should be a "Conventional" mechanic. After all some of us try to specialize in rotaries and boingers!

As for the mileage question, it also depends on the way it was driven. If that engine never saw the freeway for more than once in a blue moon, I bet you 10:1 that thing is caked on the inside with carbon. The S4 13B I cracked open ran fine, had 80k on it but had like 4-5mm of carbon build up.

I am going to assume your major leak is a coolant related one since that seems more likely than a oil leak. but that is going off your "recommends to machine the rotor housings" comment.

If its a water seal leak, depending on how bad and what it is, I know Kentestu managed to find a cheap repair that seems to be holding for now.


We really can't diagnose the severity of the engine's condition without background data.

 

funny you mention the driving habits, lol....I bought a 83 gs from a lady and this thing was never driven hard! No power over 4500 rpm at all. Did the water de-carbon trick, nothing. Fuel treatment, nothing. Took her on the highway, put my foot in it a few times, gently though, over and over. After about 30 miles it pulle better over 4500, let out a whack of black smoke and sputter at one point then "bam", just like new. It then ripped good just like she should! Now that's carbon build up! This was a $500 special that got a wet sanding, buffing, minor rust repair (bondo) and touch up, pinstriping (by me), cheap stereo from kijiji, hubcaps from the wrecker, used tires, engine detailing, exhaust and tuneup for a total investment of $1200 (including car) and a sale of $2300. Neat thing about the exhaust is everything was shot, including the manifold. 1 friend had a manifold (freebie), another had presilencer and midsection (case of beer) and I got a like new muffler from pick-n-pull ($7 bucks).

 

Forgot, need brakes too, wrecker parts, all about $20

 

Bottom line, find yourself a rotary mechanic or a nearby knowledgeable rotary enthusiast to help you. Many helped me and in turn as I have learned lots I have helped many in return, maybe you'll be just as fortunate...

 

If I was you, I would buy a rebuilding kit & rebuilding video. Watch it carefully & do it yourself. Don't trust what mechanics tell you who don't know anything about rotaries. Especially dealerships where they all want to rip you off. You'll save a lot of miney by doing it yourself.

 

^ Good advice. You will save a ton of money by doing EVERYTHING yourself. These cars are expensive enough without paying for labour. If you have a leak coming from one of the housings then there is a serious problem. DO NOT drive the car anymore. You will only make the problem worse. While your at it get some porting templates from Racing Beat or Judge ITO and port it out. Make some power while you have her open. Good luck.

 

Machine the housings eh?

 

If his motor is even shot... Where are the details? Mechanics probably have him duct taped and stuffed into a broom closet right now.

 

Don't some non-RX-7 flavors of the Wankel have the water seal grooves on the endplates instead of the rotor housings? Seem to remember having read that somewhere.

 

First of all thank you all for your quick responses, here is a link to my last posts with some info..
https://www.rx7club.com/new-member-rx-7-technical-256/my-79-rx-7-needs-help-794244/
https://www.rx7club.com/1st-generation-specific-1979-1985-18/my-limited-edition-1979-rx-7-project-794705/
( I have replaced both oil lines, the brake master cyl, the cluch slave stoping some of the leaks)

I just want to let you guys know I love my car and i want to keep her as orginal as i can, I would love to work on it myself but I have very little resources and knowedge but at the same time I am having trouble finding someone around Modesto Ca that knows about sevens..

Back to the problem ive been having, there is a pretty bad oil leak. (the shop has had experience working with sevens but way overcharges) they said it looks like it needs to have the rotor housing resurfaced or smothing like that but they wont even do it all they will do is put a new engine in, I dont really want to do that to a LE engine. She has low compression and has been floding my spark plugs, When I took it to the shop they swithched out the points and cleaned the plugs and got it to fire, they say she will run but leaks all over the place and to keep oil with me, they wont do anything else besides put a new engine in. Im going to go get her latter today and take her across the street to get an allignment I will post the latest condition of the car later.

Thx again for the help.

-Anthony

 

If the shop was literally saying they had to "machine the ROTOR housings," they know nothing about engines for the -7. Machining the rotor housing would remove or shallow the grooves for the water seals, and unless perfectly parallel, would change the alignment of the engine stack. Not to mention it would probably eliminate needed side clearance for the rotor.

With a warped rotor housing (if that's the problem; you can't tell without disassembling the engine) the only reliable repair is to replace the rotor housing.

The END housings (also called "plates" around here) can be re-machined within limits, to get rid of stepped wear under the oil sealing areas, but again, as part of a complete teardown and rebuild.

Oil leakage to the OUTSIDE of the engine is usually a case of blown o-rings, not housing warpage. Oil leakage to the INSIDE of the engine is usually a case of worn-out oil seals, which may or may not mean you also need the end plates machined (lapped) depending on their wear.

 

You keep teasing me with little bits of information. Where is this oil leaking from?

Okay, I read through your other two threads. You stated that the oil is leaking from the top right. Can you be more specific? Is that on the drivers side or passenger's side? Where exactly is it coming from? Details, details, details.....

 

Yes details, but pictures are worth a thousand typed words, so go snap some. No sorry, go snap ALOT.

As for your limited knowledge, I knew nearly nothing about rotarys when I got mine except how they worked and that I wanted an FD. Well close enough I got an FB. Love it anyway. The only way to learn anything about cars is to buy a shop manual and some tools and do the work yourself. While I admit a rebuild is a big undertaking, especially for someone that has never done one, it's also not as difficult as you might think. Start saving every penny you can. When you have enough for the rebuild kit, some tools you'll have to buy, and tool rentals, park the car, pull the motor and take a week or 3 and tear it down. There are rebuild DVD's available as well as a plethora of information on the subject on this forum, all you need to do is search for it. A trick that works well for me is I read over the part in the manual covering what I need to do a number of times before I am ready to get the work done. This way I have a very good idea of what I'm in for, and I rarely have to check the manual, except for little things that slip like torque numbers and whatnot. The only sure way to make sure things are done right is to do it yourself, and the pride you'll feel when your finished will make it all worth it in the end.

Oh an by the way, an LE motor isn't anything special, so don't worry about keeping it if you don't have to. It's the same as every other 12A engine in any other RX-7, save for beehive oil coolers and front mount.

 

where is the engine leaking oil from and at what rate? at first thought the oil cooler or lines may be at fault.

 

Hey guys I was able to take a couple pic before it got dark last night.
The shop says the leak is coming from the block between the creases.
The shop says it spews out a bit when the engine starts. You can smell it burn.
Other then that fixing the points and tuning the carb helped out she runs smooth and strong now.

I took a pic of a loose wire that looks to be a ground, It conects to the yellow wire. Can you guys help tell me where it belongs? also a pic of a loose wire clip where does this go?

Last but not least I seemed to have bumped my tired alitttle to much and now need a R/lower control arm. where do you guys sugest I can get one fast?internet?

Thx again for the help, let me know if you guys need/want more info.

 

You can get your lower control arm quickly with Mazdatrix www.mazdatrix.com
The are in SoCal so ground shipping should arrive usually in 2 days 3 days max. Or they can overnight it to you too.

 

Thx for the tip.

 

By your description of the oil leak, it sounded like the dreaded dowel pin issue, which would indeed indicate the need for a rebuild. However, looking at the pictures it appears to be your beehive oil cooler that is leaking. That is a fairly easy fix, just involving a few little O rings.

In your 4th picture, the wire you are holding looks to be the oil pressure sending wire. Which would plug into a "nipple" on the driver's side of the engine and might even be in the picture.

How much oil are you loosing? Unless you can watch the oil run out of the engine just standing there, you might try running a quart of Lucas Heavy Duty Oil Stabilizer in place of one quart of motor oil. The stuff does wonders, and doesn't contain any sort of block sealant or anything else that might cause problems.