I have an 02 plate Mondeo Estate, it smokes a bit when accelerating (or my dad says overrun??) and burns a lot of oil, but otherwise absolutely fine. HAve recently cleaned EGR valve as the light was coming on intermmittently but that seems to be ok. It did exactly the same last year, when the garage revved it for the emissions test it belched out thick smoke and filled the workshop, they suggested the head gasket may have gone and that the would do a pressure test on Monday morning. I drove it all weekend, initially there was a bit of smoke but it cleared within a couple of miles. On Monday I took it back, for the pressure test, but they couldn't get it to replicate the problem so they just re-tested it and it passed.
Any ideas welcomed as to what may be the cause, what if anything I can do? It has 124000 miles on the clock.
Thanks
Lisa

It sounds to me like there could be an oil leak within the engine - possibly inlet valve stem seals or like the garage said headgasket could be leaking oil into one of the cylinders. The problem you are describing sounds familiar with a friend who had the same issue.

It turnt out to be worn inlet valve stem seals, which would leak oil through the cylinder head and into the engine. This would cause the puff of smoke (usually blue-ish) because while the engine had been stood still for even a few hours, the oil would leak into the cylinders and therefore get burnt when the engine was started and the car driven.

The reason I think this is a possibility is because you say the engine uses a lot of oil - I would expect oil use to increase as an engine wears, but if it's excessive then the oil is being burnt or leaking, as it has to be going somewhere.

I'm not sure what the best thing to do is, you could go ahead with a compression test. A good garage (doesn't have to be Ford) won't charge too much and it will allow them to check the compression in each cylinder - if one (or two) of the cylinders is lower than the other(s), then it would suggest there's a leak in the piston rings/valve stem seals/headgasket etc - at which point the garage would probably advise they will have to remove the cylinder head to investigate further.

Best of luck getting to the bottom of this problem,

Dan

Ouch sounds expensive! Is there a way of getting it through the emmissions test so we have a bit more time to work on it?

Garage tried replacing breather valve without success and have now drawn same conclusion as you, except they say it's not worth investigating or repairing as cost is more than cars worth! Looks like another one for the scrap yard and I'll have to catch buses for a while, but thanks for your help

Lisa , it now has an MOT , so just keep topping up with oil. What the garage may have done is cleared the build up when revving. Do you do any motorway driving and what sort of Rev's do you normally reach while driving. It might be a heavy oil user and be worn , but if your not doing any motorway or low rev miles it will start to soot up .Give it a good thrash now and then.

Wife used to have an Escort turbo diesel 18 and that would always smoke alot, every so often i'd take it out for a hard drive and it would clear.

Unfortunately it hasn't got an MOT as they couldn't get the emissions down to a suitable level to pass, so back to praying for a lottery win!