Blue smoke is usually a sign that you are burning oil. There can be several reasons for it. First stick your finger into the tailpipe. If it is oily then you can be sure the reason for the blue smoke. Now check that the engine has the correct amount of oil, too much and it will burn the excess. If it is very dirty or hasn't been changed in a long time an oil change may help. Next a compression test and a leak-down test can tell the source of the trouble mechanically. Another quick way is to remove the oil fill cap while the engine is idling and if it is blowing blue smoke you probably need rings. A malfunctioning crankcase venting system can allow pressure to build up and cause oil burning. You can remove the spark plugs and inspect them for oil burning. I can give some other things to do but start with the easy ones first. The fuel you use generally won't cause this unless you have put an additive in it for some reason. Sometimes when a car is stored oil is put into the cylinders and when the engine is started it will blow blue smoke for a short time. Get it warmed up and it may go away. A cat won't cure blue smoke and if it is oil it will foul the O2 senser. David Teitelbaum vin 10757 --- In dmcnews@xxxx, "Paul Salsbury" <paul.salsbury@xxxx> wrote: > Hi all > > Just managed to get everything together for the first time since body and frame were separated. > > Now my question..... > > Background.. When I first got the car it had not been started for approx 2 years and needed a tidy up around the engine and new muffler. The tidy up was done and it started first time........ > > Now its back together with new muffler, apart from being a lot quieter, it is blowing a fair amount of blue tinted exhaust. > > What is causing this? > > I do not have a cat on the car, and do need a new oxygen sensor. could that be the easy answer? > > Any suggestions welcome > > Cheers > Paul > #6463 > > > [Non-text portions of this message have been removed]