93 LE Oil Leak

My 93 LE 4 cyl is leaking oil from the back of the engine. When parked it leaves a 5 inch spot every time. Most of the back of the engine is wet w/ oil. The front is dry. It seems like the actual drip is coming off the knock sensor which sticks out of the back of the engine block. But I'm thinking the leak is somewhere above and just collecting on the knock sensor and dripping off. Maybe the back of the valve cover gasket is leaking but if it is I can't see it. Anyone solved a leak like this before? Is there a typical cause?

Valve cover seals are know to be a problem in that engine. Distributor seals are also.

Ayup, valve cover seal. Four big nuts hold the cover on. Torque them down to 17 ft-lbs and see if that helps. Do not crank down on the nuts by hand or you can crack the valve cover itself. Use/beg/borrow a torque wrench. If the seal has never been changed it may be old and cracked, causing the more severe leak. Buy a new set of spark plug tube seals and VC seal, some black high-temp RTV silicone sealer and a BIG socket (24mm?). Changing it is quite easy. Refer to the stickies at the top of the forum for the right procedure.

"and a BIG socket (24mm?)."

The socket size is 30mm.

Mike

i agree valve covers. and when you go to replace them get rubber gasket instead of cork they last alot longer.

Replaced distributor O-ring. Waited a few days. Still leaking.

Next replaced valve cover gasket. Discovered during disassembly #1 nut was loose. Replaced the gasket anyhow. Still leaking.

Oil pressure sender does not appear to be leaking (front of engine dry).

Any other easy-to-replace suggestions?

First double check that the valve cover was torqued correctly (17 ft-lbs). There are some manuals that incorrectly state 33, which can crack the cover or crush the gasket.

The next common leakers are the camshaft, oil pump, and crankshaft oil seals. If they haven't been changed along with the timing belt, they'll crack and leak. Pull the upper timing belt cover off (after removing the coolant reservoir, dog bone mount, and mount bracket) and inspect inside. If there's oil on the belt and the engine, there's your leak.

Update: I was overdue for a timing belt/waterpump so while that was being done I also changed the oil pump and crank seals. My leaks are almost gone now. But unfortunately the oil pan seal is also dripping a bit.