My brother-in-law and I are working on replacing my oil pump o-ring due to large amounts of oil (1-2 quarts/70 miles) being leaked out. Of course we decided to do the all belts, seals, and water pump at the same time since I was at 210,000 miles. We did find that the o-ring has broken apart and was the main cause of the oil leakage. In re-installing the oil pump body to the case, we stripped one bolt and also heard 2 loud cracking noises. After removing the oil pump body, we found a crack in the casing...
gh!!!! What could caused this? We lined up the drive rotor and driven rotor, as well as the peg on the case.
So it looks like it'll be a bigger job now since we have to pull off the pan to replace the entire oil pump. Do you guys think we will run into problems with the one stripped bolt? We are not sure if it stripped at the oil pump case or into the engine.
Also, my timing belt looked very good since it was last replaced @80,000 miles. Only my other drive belts looked worn out. Is this usually the case since the timing belt is protected by the cover?
Please help!!!
Darwin
Oil Pump replacement
It worked fine until I fixed it! 
Linear Mode
