2010 1.6 tdci smoke from air intake and kangaroo

Hi,

Im new to the forum and am no mechanic by any means so please bear with me.

I got my 10 plate 1.6 tdci last year and soon after getting it I noticed a bit of a lumpy drive in low gears and occasional kangaroo type jolting also at 12-1500 revs mainly in lower gears.

I told the warranty people about it and tried dpf and engine cleaner and ran it to London a couple of times which seemed to fix it temporarily.

It soon came back though so it went to the garage and some historic error codes were reset including EGR. It ran ok for a few days then the problem came back. The error codes did not reappear and changing the fuel filter again seemed to sort it out for a bit.

When the issue returned I changed the air filter myself and it was full of oil as was the housing and hoses.

I took it to the garage and they said it was the PCV valve which meant replacing the cylinder head cover to which it is integral at a cost of £374 in vat and labour. The warranty agreed to pay so long as it solved the problem which it hasn’t not one bit. Oil is still getting into the hoses and I’ve found smoke coming out of the air intake and indeed the dipstick which I assume is causing the oil in the filter.

Im not happy with the garage as that PCV should have been tested to make sure that was the problem before replacing the expensive full cover - indeed the Ford Workshop manual states this but as the problem persists I can only asssume it was not tested and I got my car back just as bad as I sent it in.

I’ve told the warranty people not to pay out as the unessasary repair would be recoverable from me and tbh I don’t see why I should have to pay £374 for something not needed - do people think that’s fair? 

Also any idea of what the issue could be - I’m anticipating it’s somthing sinister in the engine and am hoping the warranty will cover it.

Any advice or opinions would be greatly appreciated. Thanks :)