Recent oil change now smoking!
 

Hi all,
Im new to this site but ive heard you guys may be able to help me out.
I have a 1998 s reg vito van 108d with 130,000 miles. 2 weeks ago i did and oil and oil filter change, i put in 15/40 castrol gtx deisel oil(recommended by merc dealer). The old oil was very black and thicker than the new oil, after using the van for about 3 days (50 miles) it started smoking from the exhaust. Blue/white smoke, took it in the gargage for advice and the guy said its burning oil somewhere probably caused by the thinner oil going through the worn valve stems or the piston rings. The smoke got worse so i decided to put a thicker oil in (20/50), but first i put the old oil back in just to see if it stopped (no good) so then i put the 20/50 in with a tin of WINNS oil leak sealer/stopper.
Its now still smoking, mostly in 1st and 2nd gear when excellerating but then thins out when cruising in 3rd 4th or 5th.
The engine also now has a small oil leak coming from the back somewhere, i cant see where as its too compact.(the WINNS oil sealer says Run the engine for around 100 miles) ive done around 50.
Before the oil change my van was going fine, i thought it might prolong the engine life by doing the oil change thing but now it seems ive killed the engine and lost my work van!
Has anyone got any suggestions or had the same probs?
Look forward for any help ,
Thanks scott...

smoking
 

you may have blown the head gasket