Blue and brown smoke and heavy oil consumption

[D813YBB]

My 1.6 S Series Maestro is currently experiencing the following problems:

• Blue smoke wafting by from the exhaust on idle (occurring for the last ~6000 miles or so).

• Brown smoke from the exhaust on rapid acceleration at high revs (occurring for the last 30 – 40,000 miles)

• Engine rough and vibrating when cold (for the last year or so).

• Oil consumption gradually increasing compounded by an oil leak from the rear of engine from the head gasket (Started at ~90,000 miles).

• Unfortunately the oil level has dropped below the minimum on the dipstick on a couple of occasions.

However the car still drives and pulls as normal. I change the oil every 5/6000 miles and try to keep it topped up. Is this fixable without huge expense?

[E_T_V]

Sounds like it may be running too rich to me.

If it is the excess petrol washes the oil from the bores giving excessive oil consumption.
It'll also give grey/black smoke on hard acceleration too.

Also worth checking that the oil doesn't smell of fuel. If it does then suspect a faulty fuel pump which will dilute the oil with fuel (if it is a mechanical type), causing it to thin out, burn more etc etc.

[D813YBB]

The emissions were adjusted to get it through its last MOT in May, by the garage. Do I therefore adjust the mixture screw?

[E_T_V]

Check out all the vacuum connections and the condition of the vacuum switch on the side of the carb (if diaphram is perished then replace). Also worth checking is the condition of the autochoke O rings (if they split then they tend to flood the carburettor with fuel).
Then think about giving it a tune up. Unless all of the above are in good nick then tuning it will mask the underlying problem rather than cure it, which is the usual cause of lumpy running.

There are some good bits and pieces in the FAQ section which should be of use.

One good indicator is after a good run turn off the engine. After the engine is cool examine the plugs. If they are black or sooty then that indicates too much fuel so the mixture needs adjusting.