[fronty4x4]

Hi all,,,

I have just fitted a new engine in my vauxhall frontera,, the car has run great with no problems for a couple of weeks,, however the other night i floored the car and after a few seconds saw large plumes of grey smoke pouring from the exhaust,,,,,,
Left the car overnight and started it in the morning,,, this thick grey smoke bellows from the exhaust straight away,,, it's been suggested that the valve seals may have gone,, but there is no evidence of any oil being burnt,, levels, look the same ?
The engine still runs great apart from the smoke... and doesn't overheat...
any help would be appreciated