DUDE this is so important!!!!!! with out it your oil will not go through your oil filter and will bypass it completly!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!pop it out and put a new one in , if you look closly you will see a shoulder that it seals in drive it home till it stops and you will be in good shape- the machine shop should have poped this uot before thet hot tanked it ???????????