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-   -   White smoke at start up (https://www.rx7club.com/new-member-rx-7-technical-256/white-smoke-start-up-835553/)

nh256 04-25-09 08:22 PM

White smoke at start up
 
When i first start my 84 gs in the morning, white smoke always appears about a minute after ignition. I ran a compression check when I first got the car and it read 96/100 on all four plugs. I realized the plugs were burning up faster than what they should be. This usually means it's a carburetor issue right? Any advice?

Go48 04-26-09 08:24 AM

Sounds like you used a conventional compression tester and just took the overall reading. That will not tell you much about the health of the engine. You need to do a compression test that gives you readings for each face of each rotor--i.e., 6 individual readings. For information on how to do a simple compression test, go to: http://www.aaroncake.net/rx-7/blown.htm. Otherwise, find someone with a compression tester for rotary engines and have a proper test done.

The white smoke may be an indication of failed internal coolant seal(s). That is, if it is truely white, is a wispy water vapor versus smoke, and it has a sweetish smell. However, if the ambient condition was cold and damp, it may just be condensation as the hot exhaust gas comes into contact with the cold, damp air. Or if it is really smoke and it is really a slightly bluish color, that might indicate excessively rich air-fuel mixture or excessive oil in the fuel.

Not sure what you mean by plugs burning up. What color is the center insulator after you have run the engine? If brownish/tanish, you're good. If black, your air-fuel mixture is too rich. If white, your A-F mixture is too lean or you have coolant entering the combustion area.

fcs3l0ve 04-28-09 02:38 PM

sounds like your coolant seals are blown or its just burning off condensation.

joconnell 04-28-09 07:48 PM

coolant is generally the problem if it happens everytime, regardless of your outside temperature, warm or cold.

condensation can be a factor for wisps like poster 2 suggeste, just as the said, it can happen when its cold.

CAPTN_SLAPPIN 04-30-09 10:37 PM

check for threads posted by kentetsu... he used this thing called alumiseal.

fcs3l0ve 05-02-09 10:37 AM

alumaseal works and so does blue devil sealant. thats what I used and it solved the problem for me.

mar3 05-02-09 11:52 AM


Originally posted by Go48

However, if the ambient condition was cold and damp, it may just be condensation as the hot exhaust gas comes into contact with the cold, damp air.

Not sure what you mean by plugs burning up. What color is the center insulator after you have run the engine?...If white, your A-F mixture is too lean...

Pretty much always the answer regarding the white "smoke" on start-up in the morning...UNLESS, of course, it never goes away during the whole drive...then you're in trouble. I've never burned up spark plugs, they generally just wear out in two years or so....they're worn out to me when the car won't start anymore...time for plugs!:p:

Mario III

baz_392 05-05-09 08:38 AM

can you smell antifreeze in the exhaust?

jamie97M1 05-05-09 10:51 PM

White smoke usually means coolant being burned. Does the exhaust smell sweet??

mainlymazda 05-08-09 02:37 PM

White Smoke
 
If it is truly white then it is definitely water. A couple possabilities exist.

It is either real expensive because the engine was overheated or it could just be a bad seal.

One area that is overlooked is the o-rings that go between the intake manifold and the housing. It may be leaking when cold. This is usually from corrosion of the rotor housing or intake manifold.

Using a stop leak is a short term fix. It may hold off leaks for a while, but eventually you will need to do something to the engine.

Sorry, it's not better news but that is the reality of it.


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