common oil leaks for EJ engines.
1/ NOT the rear main seal. they usually last the life of the car or until someone replaces them incorrectly. so NOT the rear main seal.
2/ oil separator plate on the rear of the block next to the rear main seal (behind the flywheel / flex plate, depending on the trans.) lots of these were plastic covers from the factory and over time they crack at the screws. if it has not been change this is the leak on the rear near the trans. not an expensive part, but you have to pull the engine to replace it.
3/ valve cover gaskets (rocker covers?) and spark plug tube seals (if you have them, DOHC?) you did replaced these so no problem there.
4/ front crank shaft seal / oil pump seal and o-ring. this is usually addressed during a timing belt change. it can cause oil to drip off of the front bottom of the motor / oil pump. also check the screws on the back side of the pump backing plate. they can come lose. they do not really cause a leak but the can cause lower oil pressure.
5/ cam shaft seals, again, these are usually done at the same time as the timing belt. but if they are leaking, they need to be done even if the belt is not. but the only money you will save by not doing the belt is the parts, the labor is the same.
6/ and a few folks have reported oil leaking from the oil pressure sensor on top of the block under the intake and / or the alternator. it is a single wire sensor threaded into the block.
7/ other leaks, other than engine oil: the power steering pump. this usaualy it caused by a bad o-ring in between the reservoir and the pump. cheap part and easy fix.
8/ finally it could be the head gaskets. not common for most EJ engines except the ej25, 2.5L . and then external oil leaks are usually only common in the 00 - 03 model years (US). but it is possible.
i would do the leaks on the front of the engine first, timing belt too unless you just did it. (if the belt is oil soaked i MUST be replaced. )and i would save the rear leak for when you need to pull the engine for some other reason, clutch, head gaskets, valves, what ever.
but if you are committed to fixing the leaks, pull the engine now and do them ALL, (front, rear and top?) with the engine out. and do the timing belt and clutch at the same time. then reinstall the engine and drive it for 100k.
Last edited by johnegg; 04-15-2013 at 07:07 AM..