So i checked out this rx7 that had been sitting for a good six months maybe more and it has 100k kms on the motor and body and he started it up for the first time in awhile and when he finally got it going it was smoking quite a bit but started to smoke less the more the engine was warm. He said that the more you drive it the less it may smoke and that all rx7's smoke like that and the blue smoke never stopped while i was there either? it was only a little bit at idle and i dont know much about rotaries but i have been getting mixed answers about this problem when i searched for a solution

 

Rx7's inject oil into the fuel to lubricate the Apex Seals. They always have some sort of a smoke especially on start up. General rule of thumb on a rotary blue smoke is fine, Black smoke is fuel mixture wich is fine. White smoke is bad news.

 

If the smoke smells like oil, and the crank case is not overfilled, then you are looking at worn oil control rings. To replace them, you need to rebuild the motor.

However, having said that, I will tell you that I "dealt with" this issue for about 20,000 miles on an old motor. Using 1 quart of Lucas Heavy Duty Oil Stabilizer in place of one quart of oil reduced the smoking by about 95% and the motor lived to a ripe old age of 213,000 miles before coughing up an apex seal.

Good luck...





.

 

AND - if its the WHITE (ish) smoke - you will be able to smell the coolant (sweet smell) - this does go away once the engine warms up (unless _really_ bad) because as the engine heats to operating temp, the expansion reduces the leakage between the water jacket and the combustion chambers. BUT - as soon as the car parks, the engine cools, the housings contract, the water starts leaking back in, then its All-Over-Again until finally the car starts over heating and the engine finally cooks itself, by which time there is not much that can be salvaged in a rebuild...

And unlike above "additive" cure for oil burning, there is no similar fix-all for coolant leakage (NO the rad stop-leak does not work!), except a rebuild.

If in doubt - walk away!!! LOTS of RX7 out there.

Stu Aull
80GS
Alaska

 

Huh?

With all due respect, I beg to differ. Alumaseal works great for this, especially with 12a engines. 30,000 miles since I treated my "blown" motor.

 

I defer
had heard otherwise that such stuff created a clotted mess. But maybe diff product?

Stu Aull
80GS
Alaska

 

Yeah, the block sealants are what you are thinking of. I've seen some photos, and have even tried the stuff on piston motors a couple of decades ago. Made a mess, and didn't do the job.

The Alumaseal works great though, as long as you are losing exhaust out the tail pipe. Seems to be more effective on the 12a than the 13b due to design of the seal or recess. To date, I've advised 29 owners on this repair. Success rate for the 12a is 22 out of 24 (and I suspect user error on those failures), while the 13b is 2 out of 5.

Most of those who oppose this idea seem to be engine builders. Claims of doom and destruction abound whenever I bring this up. If I ever need one rebuilt, I probably won't get a very good deal. lol. But honestly, if the only problem with the motor is the coolant seal, I can't see dropping a grand on a rebuild when $4.00 in a bottle will produce the same results...



.

 

is Gunk Brand M-P Radiator Sealant and Conditioner the same thing or just as good? I bought some but don't dare until I get feedback.

 

The only product that I have tested is Alumaseal. I chose it specifically because it was based on Aluminum, rather than Copper or some other metal. I figured that if aluminum flakes got into the combustion areas, they will burn. Copper may stay there and tear things up.

I would make sure I was using Alumaseal, since it has been tested and proven to work without nasty side effects.

 

Hate to be contrary, Drake, but not all rotaries smoke visibly. A fresh engine in proper tune smokes not a bit. Older motors will possibly smoke a small amount upon startup, but once warm exhaust should be invisible - - and nearly odorless - - on an un-stripped motor.

Do RX-8's smoke when new? No. Neither did first gens when they were new.

It's just getting to be rare to see one that's fresh, running properly, and has it's emissions gear in place.

 

Well, water under the bridge (or anti-freeze through the combustion chamber) I put it in. We'll see I guess.

 

Hello! I am 7 years late to the discussion. Currently restoring a 1979 GS that probably needs help from additives. It has been sitting mostly for the past two weeks while I performed the basic maintenance. Started it up briefly to check but no driving. To wrap up and coolant change, I started it and kept it running for more than five minutes. What looked like white smoke in the beginning actually has a tint of blue. From what I have read, that's a bit much. 80K miles and stock everything. Which Alumaseal product works best? So far my search has shown the radiator stop leak product.

 

Alumaseal will only work for a bad water seal. Blue smoke indicates oil. I wouldn't use Alumaseal myself. If it's blue smoke, its probably a bad oil seal or apex/side seal that may fix itself after some run time. I would run it for a a few days on the road before doing anything like resorting to Alumaseal.

I'd replace the intake water seals and gasket along with all soft rubber lines, especially ones with gas going through them. And don't forget the fuel filter.

 

Thank you. I hope to drive it soon after the idler arm is replaced. In the meantime time I removed one quart of the newly changed oil and poured in one quart of Lucas oil stabilizer. I was surprised to see that my new oil came out black after just sitting in there for three days (car was started briefly after the change but otherwise remained dormant.) Yes, fuel filter is part of the task for when the rearend is jacked up for fluid changes.