Blue smoke, but strange symptoms

[davidbr]

My 1.9 TDI has recently started pumping blue smoke, but the symptoms are a little strange (to me) and don't seem to match up other threads on the subject.

Here goes:

• Blue smoke only at tickover and low revs
• No blue smoke when accelerating hard or when cruising
• No alarming oil usage
• No loss of power, flat spots or fuel consumption
• Smoke levels the same when hot and cold
• Very occasional cold start problem. It immediately starts and then stops. Needs about 10 seconds of cranking to get it going.

There are a couple mitigating circumstances

• The car was recently accidentally filled with petrol, run for about half a mile (oops)
• Fuel was drained, flushed, fuel filter changed, refilled with diesel

Now I'd accept that there may have been some bore/ring/valve stem wear with running on petrol, but why does it smoke only at low revs and not all the time. Also, the oil level is not consistent with the amount of smoke - to my eyes.

Any thoughts?

[adamss24]

I think you will need a new cylinder head. Also, you wont believe how much smoke a little bit of oil can make...

[tdi miki]

Diesels are different than petrol cars when it comes to smoke.On diesels smoke is more fuel than oil related.What is the engine code?

[adamss24]

Diesels are different than petrol cars when it comes to smoke.On diesels smoke is more fuel than oil related.What is the engine code?

In a diesel engine blue smoke= burning oil(possible worn piston rings, valve stem seals or blown turbocharger seals), black smoke= unburnt fuel(too much fuel not enough air !), white smoke ( burning coolant)= blown gasket when the engine is at normal operating temp. When its cold, one can see white smoke smelling of diesel. This is unburnt diesel and ussually clears after a few minutes. This is to help the fuel ignite quicker and to aid cold start. The diesel vapours condenses on the cold cylinder walls and wont ignite(they drip down washing the oil film off the cylinder walls !) - thats why is not indicated to let the engine iddle in cold wheater. Due to the fact that diesel engine is soo eficient compared with petrol engines, they actually cool down when idling and to get it to operating temp it has to be driven straight away.