exhaust emits excessive dense blue smoke during acceleration - 1998 ford galaxy 2.8 v6

dipsomaniac

Took car for MOT yesterday. They couldn't do a emissions test as 'exhaust emits excessive dense blue smoke during acceleration.' I haven't had a problem with emmisions in the 18 years i have owned the car and i didn't notice any smoke when taking it to the MOT station.

the car has been off the road for 18 months as i have renewed the head gasket, had head skimmed, and all associated valve work (new guides, grind and lapped etc)

I haven't had chance to take car for a long run as its not taxed until MOT'ed. I just drove 2 miles to MOT station.  Do you think the smoke will clear once the valves settle or if any build up of oil in exhaust has cleared?

Was concerned that i might have been 1 tooth out on timing chain but engine appears to run ok, ticks over smoothly at 800rpm.

Any advice appreciated

tacpot12

Yes, I think the smoke could well clear after the engine has been run for a bit. I expect there will still be some assembly lubricant in the engine (if you used it, and the valve stem seals will be new and might need to bed in slightly. I'm not sure why there would be oil in the exhaust, but if there is any, then a good run should burn it off. Of course, you might have assembled the engine incorrectly, and the problem may never clear without the engine being dismantled and reassembled.

I would be inclined to book another MOT test at a remote testing station - somewhere you will have to cruise at motorway speeds for an hour to get to. This should sort the problem out if a run is going to sort it. You might be able to negotiate with the testing centre that they fail the car immediately with the same fault if you find the run hasn't sorted it, and will not charge you the full price if they don't have to check everything else on the car. You will have to put it through an MOT, and have it fail in order to legally drive it back. 

dipsomaniac

thanks.  i did have to take the CAT off and had some welding done on the exhaust manifold so there was some disruption to the exhaust.  i did clean up the pistons and block so hopefully it just needs a good run.