9 replies to this topic

[Mini'92]

Hi,

I have a '92 mini cooper with a spi engine. I have recently fitted a new play ,mini exhaust including back box tail pipes and a link pipe. Since then it has started to smoke when started up from cold. If run for for a while this seems to get better but then re-appears when accelerating.

Could this be down to the new exhaust? should it have a cat where the straight link pipe is? could this be causing the problem?

Any help would be much appreciated.

Chris

[minimole]

could be a few things really, what colour is the smoke

[Mini'92]

Hi,

It seems to be a big cloud of white smoke when it hasnt been started for a while. I think this is probably rain water collecting throught the inclined tailpaipes. As it does seem to clear when it is run for a while.

The real problem is black smoke appearing and even more so when accelerating.

Thanks

[miniboo]

If you think it is rain water, drill a hole where the pipe first starts to turn up.

should help drain the water

[Jackman]

Mine does that on first start up, its just moisture and condensation from the air, it will form on the inside when cooling down but once you get going and it wams up it evaporates. If its doing it all the time then it could be the head gasket and its leaking water into the engine. I think you would notice the water level going down too.

[1984mini25]

The real problem is black smoke appearing and even more so when accelerating.

might be running ritch at bottom end of the rev band

get it on a rolling road to set the fueling up properly

[Sprocket]

How does the engine run in general, is there a feel of any flatspots in power? is there a missfire?

There usualy is a lot of condensation with injected engines but is usualy down to the cat, which you say is not fitted. Water will condense in the exhaust more so in a straight though system, this will disipate as the exhaust warms. the only other thing is oil smoke. Oil smoke hangs about in the air longer than the steam and has a blue grey tinge to it with a kind of melting plastic smell. If its oil then it may just be valve guide seals allowing oil to seep into the combustion chamber and build up when the engine is not running. If the engine smokes badly on acceleration then the rings/bores are worn.

If the Oxygen sensor is not working correctly it can either cause rich or lean mixtures. If you say there is black smoke then its rich, the oxygen sensor may be telling the ecu that its running lean when its not but will add the extra fuel anyway.

When was the oxygen sensor last changed?

Also, replace all the vacuum capilary elbow ends.These are the thin black, red or yellow pipes running from the back of the manifold with either black or brown elbow ends. These have a tendancy to split more often than not causing an air leak that upsets the fueling.

[Mini'92]

Hi

I have just checked under the bonnet and found the red pipe but it has been blocked off at the brown elbow end. where shoould it connect to? there is a k&n filter!

Have no idea when the oxygen sensor was last changed, but it certainly hasn't been changed in the last three years.

thanks

[Sprocket]

With the K&N the red pipe is not used and as you say is plugged off. Make sure the black end of it, on the manifold, is in good condition though.

The oxygen sensor is on the exhaust manifold and can be seen if you look down to the left of and past the injection manifold. There is a sensor with four wires. If you haven't changed it, and the engine shows signs of failing emissions then I would advise changing it only with a genuine Bosch item. Also make sure you are using the correct spark plugs NGK BPR6ES.

To understand a little about Oxygen sensors and thier problems read this http://www.picotech....bda_sensor.html

[Mini'92]

will have a look.


Thanks a lot.