FrostDrew

Hey,
I just purchased a 1985 Mazda RX-7 Rotary about a week ago. Since Ive had it, it has been blowing white smoke out the back when it is getting warmed up and its using a lot of oil. A friend of mine thinks that the seals might be bad and that is what is causing it. also note that the previous owner had it sitting for a long time without any use. The car has about 159,600 miles on it. Anybody have any opinions/suggestions? I would much appreciate it. Also, would using a heavier oil be better for it (w20-50)?
-Drew

Rx7carl

Hi and welcome to the board. White smoke is a sign of burning coolant. Check/fill the radiator and keep an eye on it. Once its warm the smoke stops? How much is it smoking? How much oil is it using? Rotaries inject oil into the engine to lube the seals so some oil use is normal. Read the FAQ thread at the top of the page. Lots of good info for a new owner.

FrostDrew

Yes -- when it gets going the smoke does stop... but the first couple of days i had it, the smoke billowed out in clouds- when i would get on the freeway etc... Ive been adding about a quart of oil every other day or so -- is that normal??

mazdaverx713b

iTrader: (91)

not normal unless you are driving 500 or more miles in a day. maybe your omp is running constantly.

FrostDrew

well im not driving nearly that much, but it is leaking slightly (but not that much). and the smoke smells like oil. I was also using 30 weight oil. does this sound like a bad seal??

mazdaverx713b

iTrader: (91)

i wouldn't use 30 weight. no no. a seal, not really. it could be wearing though. when cold it leaks cooland into combustion chamber. when warm, it expands just enough to seal itself again...just a thought

FrostDrew

"not normal unless you are driving 500 or more miles in a day. maybe your omp is running constantly."
_____________________________

whats the omp?

so, does the lighter 30 weight cause more oil use or what?

mazdaverx713b

iTrader: (91)

omp is the oil metering pump. it injects oil into the carb to lubricate the gas seals and to lubricae the trichoid surface on the housings in the combustion process. i guess its kinda like a 2 stroke

Aviator 902S

The omp is supposed to run constantly. It meters a small amount of engine oil fron the oil pan into the carb to lube the apex seals. It should only use about a quart every 1000 miles or so.

And the whitish smoke that you see when the engine is still cold is normal. If it's still there once operating temps are reached (especially if you continually have to top up your coolant and your temp guage is climbing more than 1/3rd of the way up the gage) you have coolant seal leaks.

Have you pulled the spark plugs for inspection yet? Are the electrodes ans insulators on the business end of them dry and either tan or grey in color? If so, the engine is not burning excessive oil. I'd look for leaks instead.

But if:
a) the plugs are oil-fouled,

b) there's a continuous big-*** white or blue cloud of exhaust at normal operating temps,

c) coolant levels that won't stay full,

d) any evidence of oil in the coolant or vice-versa,

e) any evidence of coolant on the spark plugs (insulators will be steam-cleaned nice and pearly white),

YOU'VE BEEN HAD. Go after the ***** who sold you the car and promise to let him live and only break one of his legs if he gives you an immediate refund. This engine requires a rebuild and that's why the car was for sale.