I know rotarys leak oil,but is there a common area where they seem
to pop a leak always,,and what did you do to repair it ?? how long
has the repair lasted ??

 

mine leaks from the oil cooler mounted under the oil filter. tie a clean rag under it for a while and if it is soaked in oil then there is your prob. If this is the case the easiest way to fix it is to get a radiator style oil cooler from an older 1st gen or an rx-4(which is a little bigger), and do away with the one mounted under the filter.

 

Rotaries don't leak oil more than any other car. Rotaries don't do anything bad.

-The oil pan is common, as with any car: don't use a gasket, just seal it with black hi-temp silicone sealant. Usually have to re-seal it every 5 years or so, as with any car.

-Under the oil filter mount: there are two o-rings. Easy and cheap to replace.

-If you have an oil cooler under the rad (13B): That one is a problem. They tend to crack at the hose connections, even when not over-tightened. I had mine welded and built up around the base of the nipples. That was about 12 years ago and it doesn't leak. If it has cracked through to the inside and the threads are shot, you can find a replacement on the Net and have it welded before you install it.

-If your oil hoses to and from the cooler have not been kept clean, and have had oil or other fluid leak onto them, the residue will eat through them and cause a leak, sometimes a rapid and severe one. Check them for signs of wear. If so, change them before they leave you stranded.

-The rear oil seal on the camshaft tends to leak. That one is VERY expensive to replace.

Anybody else know of other leaky areas?

-John.

 

I hope you're kidding about #5

I should note that oil leaks at the oil filter tower/oil cooler assembly ('83-85 12A) should be repaired ASAP. Oil leaks on to the heater hoses and weakens them, causing them to rupture. It looks like there's only 2 O-rings to change but it's actually 4 (just found that out actually). I'm going to have to change them soon as it leaks quickly enough to drip every couple seconds when idling! (not to mention that a heater hose burst on me )

Also if you use that cooler, it runs the oil pretty hot. The top dowel pins that hold the engine housings aligned double as an oil passage, and O-rings seal them between thousings. The hot oil cooks those O-rings and causes a mysterious oil leak at the top of the engine, usually at the front. Look for puddling where it says "12A" on the rotor (aluminum) housings. You replace them by disassembling the engine. Very not cheap unless you're a DIY kinda person. To prevent this, use an early style oil cooler. In the meantime I'm crossing my fingers and running Water Wetter in the coolant, hoping that it will help take more heat away from the oil.

 

Rats !!but thanks,now i know,,because oil does puddle right on the engine stamp 12a on the housing,,not too much thank god,,i just replaced
the oil cooler under the rad.bought brand new from mazdatrix,and new
s.s.oil cooler lines too,,i've been beating myself up trying to find where
the oil is coming from,other then that the engine is dry,,"o" rings,,,,huh.

 

My leak is around the oil pan, and it only leaks a tiny bit--a few drops every day. Is it worth the trouble to un-screw ALL of those bolts and seal it back up? (I have limited time on my hands... else my 7 would be in super-duper tip top shape )

 

Hmmmm..... I ran mine with a leaking oil cooler for about 3 years, 8 months and it never hurt anything, just leaks oil. Yes, oil on rubber hoses is *bad* but I would not make it sound quite so dire..... The hoses aren't cheap either but, it takes years of oil soakiing to really harm them IMHO.

The repair is messy and generally on the much less than fun scale of things you can do on your 7. If it were me, I would wait until the next time you flush the cooling system and change the oil, it decreases the messiness a little....

 

Keep in mind that you're dealing with someone who just HAD a hose rupture due to the oil soak problem.

Felix Miata said that it's the #1 cause of death for '83-85 12As... hose blows on the road, coolant leaks out, it takes a little while for the coolant light to come on, by that time all of the coolant is out of the engine.

 

To me, it depends on where you park. Mine is starting to leak again (it's been 6 years since I last sealed it so it's due), but my garage has a painted concrete floor. A handful of sawdust and the few drops are gone. If you leak a few drops onto a driveway every day, it will eat the asphalt or stain the concrete. Makes it a more pressing issue.

And yes, peejay, I was kidding about the camshaft seal above. But I didn't know the 12a has 4 o-rings under the filter. The 13b only has two.

-John.

 

FJ: I put cardboard under my 7 so that the oil does not get on the cement
If i have time in the future, I may just take the pan off and then seal with some hi-temp sealent... should i get the gasket and put the sealent on that?

 

No gasket...
It's a bit of a pain to do, and scraping off the old gasket/sealant is the worst part (as usual) but a few hours and your done. No more cardboard. I have re-sealed mine a few times over the years: the original gasket and the one time I put one on, I had to re-seal the pan too early. Don't put a gasket, it leaks much quicker than just the black (not red) sealant. Do a search on the forum for "oil pan gasket": it may back me up, maybe not: I'm just mentioning what I've found to work. Actually, I think I'll do that search also...

 

Resealing the oil pan on an FB is easy. The FC's suck becuase there is a motor mount bolt going through it, neccesitating a cherry picker

 

I have the same problem of oil puddle on top, only I have it at te front and at the back seal, right next to the oil filter ( Where do you get those o-rings, I want to change them just to be safe ). Mine leaks a fair amount from these areas. I have an se ( 13b ), and I thought that the se's had a better oil cooler than the 12a's. Is there anything I can do to help/fix this short of a rebuild?

 

bump

 

This just stuck out on my mind this time I read this post, but NO engine should leak oil...

Any engine will leak oil if the seals go bad or if things are left loose.

Rotaries are supposed to BURN oil, however. Either premixed or injected from the sump.

Order your sels from www.Mazdatrix.com

 

The 84-85 oil coolers on 12a sucks. The one on my car got plugged oil got so hot it backed the easy grip off the filter and the motor went boom. But if you have seen the pics i think i have that problem taken care of but i have another one now. It won't start!!!!!!!!!!!!


dan