I have an '06 Fiesta ST with 30k on the clock
I bought it 2 years ago with 20k, and it's been fully serviced at Ford since.
I fitted a Mountune 165 kit soon after buying it (filter, exhaust, and remap)
I don't drive it hard, I very rarely take it past 5k rpm, and it's used for a variety of journey types - but mostly the 10 min run to the station daily, and about 1 hour runs to see my family every couple of weeks.
It's always used a little oil - I heard they all do
- but I have always kept an eye on it and kept it topped up with good quality oil. I may have slightly overfilled it once as the dipstick is a nightmare to read.
About 6 months ago it started smoking massively, but only under very specific conditions:
It does not smoke at idle, or after starting
It does not smoke at low road speed (high or low rpm)
It only smokes after a reasonably long run on a main road (over ~1/2 a mile) at over 65-70mph, and is worse if I back off (on overrun), then accelerate again. This sort of makes me think blow-by is not an issue as it's load related not rpm related, and on overrun it will generate more sustained vaccum in the inlet than at low road speed (the vaccum variable makes me think faulty PCV?)
The smoke is not just a puff, it properly blots out the sun! It'll lay a screen the army could use to move a division under cover!
All other times it drives normally, but I can't take it on the motorway or dual carriageways currently... and it's been getting slowly worse..
I took off the air filter (The Mountune kit uses a K&N), and the inside of the filter and housing was dry. The breather from the rocker cover was dry.
I opened the throttle butterfly, the inside is soaked with oil. The outside was dry
I gave it a compression test, all 4 cylinders between 140-150psi. No massive variation
The plugs were very brown, but not wet.
Any thoughts? Is this a common problem with the 2.0 Duratec?
My first step will be to strip off the inlet manifold, clean it, clean the throttle butterfly, and replace the PCV valve.
Anything else I should do?
Thanks, any relevant advice appreciated.
Tim