1998 Toyota oil leak- replaced the valve cover seal about 2 months ago. Just discovered A puddle of oil under the car. It does not appear to be leaking all the time. It appears to be intermitent. Any thoughts, maybe something to do with pressure?

Oil loss comes in two flavors - it is either burning the oil or leaking it. Bad oil seals and gaskets leak and can be a serious issue - but repairable relatively easy depending on the specific culprit. Engines that burn oil have bad piston rings and you would see a lot of exhaust smoke in that case - this is an expensive repair and you should replace the gaskets and oil seals if that needs to be done to save yourself problems later. Once you seal the piston rings and pressure increases in the engine you may discover leaks in the crankshaft seals or valve cover and oil pan gaskets.

IF you are extremely fortunate this could be a loose oil filter problem and the cure then would be to do an oil and filter change.
May you be fortunate.

Fix it or sell it, that is depending on overall condition iof car which you don't give.

there are o-rings that are under the valve cover that seal the valve cover to the cylinder head, they are leaking and allowing oil to leak from under the valve cover into the spark plug wells, all you need to do is replace the valve cover gaskets and wa-la the oil problem will be fixed.....good luck

i would check the oil pan gasket, front crank shaft seal, and valve covers. This are common leaks on most gm cars

You should get it up in a hoist and look at lower side of engine. Could be rear seal or something as simple as valve cover gasket leaking. It's probably a simple gasket that needs replacing but don't put it off, leaks don't fix themselves they only get worse.

If you have no visible signs of oil leaking out of the engine then the oil is being burnt. By visible leaking I mean a small puddle of oil under the car after having been left overnight. This can be cured by replacing shaft seals and gaskets. Burning oil is visible as smoke under deceleration (no throttle) and under full power(flooring it). This is due to worn/old valve stem seals(smoke under deceleration) and worn oil rings(smoke under acceleration) This can only be cured by a major engine overhaul or engine replacement. Bear in mind that losing a pint of oil in 1000 miles is acceptable.

same here on my rav4 1996,i just put in oil stop leak been ok for 8 months :) you will always get hatters of oil stop leaks,but they work ok,though i find don't like them have never used them

I have the same car and the same problem. I can see the oil shooting out at the (upside down) rear, right side of the oil pan. This side of the oil pan is covered by a piece of plastic foam. There are no bolts on this side of the pan. Toyota recommends grey Formagaskit to seal the pan. The natural flow for this leak is all over the bell housing. The piece of plastic foam is attached to bell housing inspection cover. Good Luck!!!

Anything over 1 quart in 1000 miles might be considered excessive. It probably is not gaskets unless there is a leak. If there is a leak there might be a puddle of oil on the ground where you park it. If there is a puddle or drips of oil look at valve cover gaskets, oil pan gaskets, crankshaft seals , etc.

You must use 5w\40 or 10w\40 remember BMW recommends castrol for engine oil