I have a 1981 Mazda Rx7 that was driven very far for over two years.

It has a stock carb and no cats except for the rear muffler. When i drive it normaly it's fine, but when i get into the 4000 rpms and hold it their for a while it smokes as soon as i take my foot of the gas, or shift. It smokes alot, like a cloud of smoke.

Another i noticed is when i drive up the hill on the highway from spokane towards seattle, the cars oil pressure drops from around 60 to just above 30, not to mention that the tempreture rises from just above cold to the midle. Then the car loses power until i get over the hill and the road stratens out, then after 3 minutes the car returns back to normal.

 

What color smoke? From the exhaust or engine bay?

 

If its like mine, its blue...which would mean failing oil rings. I wish it were my OMP (FC3S) but yeah. Whats the oil level like after? Do you have to add much?

 

mine does this too but only past 6k rpms, im not sure why. and its always a long stream of white smoke

 

How many miles are on the engine? I may simply be that it's getting tired and old. Fwiw, 4k rpm is mid-range for rpms. Smoking, when backing off the throttle is usually an indication of worn oil control rings, if the smoke is blue/dark. When's the last time you changed your oil and what weight are you running?

 

I've used Lucas Heavy Duty Oil Stabilizer (damn that's a long name) before to control this issue. I was leaving a James Bond smoke screen, and the Lucas took care of about 95% of the problem. I used 1 quart in place of 1 quart of oil.

The engine had over 210,000 miles on it, so not many parts would be reusable in a rebuild anyway. I was able to get about another 20 thousand miles out of it before it finally lost an apex seal and was retired.

.

 

Yes it's the long stream of white smoke coming from the exhaust, the engine i asume has over 200,000 but the ODO says 000000. I changed the oil at walmart with the best they had, and then raced it and a few days later added 3 more quarts of chevron 5/30 oil. I don't thing the plugs have been changed in two years. The carb is stock. i put some seafoam in the oil and gas tank, but i did not drive it since then except for 10 miles. Atkins rotory is about two hours away from where i live, and i was thinking about getting a motor from there if my one is doomed, what do you guys think?

 

White is coolant, not sure why it would only show up after 4K though. Maybe an intake manifold gasket leak from the coolant jacket to the intake port because of the higher pressure.

 

it smokes at 4-5 when i hold it there for a few seconds.

 

If it is the coolant leaking, would'nt i notice a low level in coolant ? because i have not notice that yet. let us say it is, how would i fix this problem ? and where can i get the parts for it ?

 

it may not help you but I would use 20/50 instead of the 5/30 that is very thin oil in our engines

 

That too bad , but i will try that. what about the heating ?

 

Dude ! i used the 20/50 and it caused the car to smoke even worse. Now it smokes at the touch of the peddle -_-

 

oil control rings are toasted. best bet is to just stop using the car before something catastrophic happens on the road or leaves you stranded somewhere.

if you still decide to keep running it till it just dies, then replace those plugs NOW. NGK's are the way to go

 

Not to thread hijack,

Mine leaves a nice smoke cloud if I rev it up to 6k or 7k and downshift occasionally, especially right after warming up the car for driving it. Similar issue do you think?

-I just replaced my intake manifold gasket because i was having issue with a coolant leak there.

 

Oi control rings. Check out one of the many threads on Lucas heavy duty oil stabilizer....

 

I used the Lucas oil stabilizer, but i will try useing a lower grade of oil of 20/50 and see what happens. The plugs are new and the engine runs and sounds normal even when it smokes. Could it be radiator fluid leaking into the engine ? if so what do i need to replace it and where can i get it from ?

 

Did you check the oil level? If you overfill the system, it will blow out your oil control rings in short order. That's what happened to mine a couple years back when I followed the instructions in the Hayne's manual without realizing that the information for my year was in a back section.

Also, the thinner the oil the more smoke you're going to get. Stay with the 20/50. Are you sure you have the correct oil filter on?

 

i put a K&N oil filter, and i don't think i over filled it.

 

+1! i swear by that lucas oil stuff too! i use it every oil change. I didn't start seeing the ful leffects of it until the 2nd time i used it. USE IT! it works!



i sound like a damn infomercial lol

 

Alright i give up.
i want to know where can i get the best deal on an engine rebuild kit, so that i can throw the turbo that i have on and race the my rx7 -_-"

 

check out stkins rotary. all sorts of packages and they accomodate requests for different parts, like 3rdgen corners etc.

 

That's Atkins Rotary

Did you ever check the oil level? You stated that you "didn't think" it was overfilled. Dude, pull out the damn dipstick and check it already! New engines are expensive man....

 

good call on spelling error and dipstick checking lol.

 

LoL, yes i have checked the oil level it's below full.