Advise required

[Martin Higgs]

Hi
I have taken the engine out of my MK this afternoon (2lt pinto) to try to discover why I had such a bad oil leak, the rear Crankshaft oil seal has fallen right out the engine has only done 5o miles since it was rebuilt. does anyone have any clues as to why it could have fallen out, could I have fitted it incorrectly? I am a bit worried about fitting the new seal and haveing the same problem again any suggestions would be welcome.

[Quarrycars]

Check that oil can drain away from behind the seal, there may be a drain slot in the rear main bearing cap.  While the engine is out it might be worth checking the rear main bearing, too much clearance may result in exessive pressure on the rear seal.  Make sure the crankase ventilation system is working.
JT

[Denzle]

This seems to be a serious problem with the 2.0 pinto engine
Many times I have read about the rear oil seal failing.

The builder of my car told me he had replaced the seal before selling to me, with only 3.000 on the clock from recon engine.

Interesting to watch the answers on this one.

[Quarrycars]

The fact that the seal had blown out of the engine (assuming it was a good fit and didn't fall out) indicates exessive crankcase pressure.  It's been a long time since I worked on this engine and I have forgotten how it is vented.  The standard PCV system should provide a slight negative pressure at light throttle openings but may not provide sufficiant venting at WOT.  A couple of large diameter vents and a catch can may be the answer although that may not be legal for emmisions.
I think you mentioned that the engine had just been rebuilt, the rings may not have seated  yet and the blowby may be adding to the problem.
On competition engines we always added retaining bolts to the oil seals and core plugs, probaly an overkill for a road engine.
Cheerz, JT