Blue/Black Smoke on heavy acceleration???

[stev580]

Over the last few weeks i have noticed blue/black smoke coming from the exhaust of my 89 S2. It seems to happen under heavy acceleration or revving the engine when stationary.

I have also noticed small amounts of white gunk gathering around the oil filler cap. (not sure if this is just condensation gathering because of my short journey to and from my work)

Does anybody have any ideas whether it could be valve stem seals or a possible head gasket on its way out????

Any help appreciated

cheers

stev

 

[zcacogp]

Can't be much help, but smoke on acceleration usually means bores (as opposed to smoke on idle, which would suggest valves.) But this is a general rule, and I don't know the specifics of the S2 engine.

How short is the short journey to work?


Oli.

 

[stev580]

My Journey to work is maybe a 14 mile round trip.

 

[Diver944]

If it is black smoke then that is excess fuel and could be many things but I would look firstly at the engine temperature sensor which is blue, on the passenger side of the block just below the first intake manifold. When it fails it makes the ECU think the engine is permanently cold so is like running with the choke out all the time

If it is blue smoke then that is oil (see Oli's post above)

White mayonaise around the filler cap and dipstick is very common on our cars at this time of year, especially if they are not driven fully hot for a long journey to burn it all off. It is simply condensation.

 

[stev580]

Its more a black smoke.

If it is black smoke then that is excess fuel and could be many things but I would look firstly at the engine temperature sensor which is blue, on the passenger side of the block just below the first intake manifold. When it fails it makes the ECU think the engine is permanently cold so is like running with the choke out all the time

Is there any way to test the sensor or is it just a case of replacing it and hoping for the best??

cheers

 

[Diver944]

Here is the page from the workshop manual that covers the sensor. It gives the resistance values that the sensor should read at various temperatures. The manuals are normally available for download at www.cannell.co.uk

 

[egan1]

Clark's Garage has a procedure for testing the DME temp. sensor at http://www.clarks-garage.com/shop-manual/elect-19.htm

It may be easier to unplug the sensor and measure the resistance across the 2 pins of the sensor.

 

[stev580]

Doesnt look like ita an emissons problem.

Its looking more like valve stem seals. Does anyone know if its a cylinder head off job or can the valve seals be done with the head still on??

cheers

stev580