If you own a Toyota Corolla or Matrix with the 1ZZ-FE or 2ZZ-GE you may be familiar with an oil leak from the timing chain tensioner out the back of the engine. The timing chain tensioner keeps tension on the timing chain, pulling the camshafts in time with the crank, and is installed into the back of the engine at the intersection of the cylinder head, block and timing cover. When it leaks it looks something like this (a view up the back of the engine):

Tensioner Oil Leak

Tensioner Oil Leak

The tensioner leaks down the back of the block onto the power steering pump and crank pulley, and eventually down the oil pan onto the ground. If oil finds its way onto the serpentine belt the belt can slip, tear or break.

Repairing the leak involves replacing the failed O-ring that seals the timing chain tensioner. The technician removes the valve cover, sets the crank and camshaft to top dead center on cylinder #1, unbolts the tensioner, replaces the O-ring on the tensioner, resets and reinstalls the tensioner, and reassembles the valve cover with a new gaskets. Resetting and unlocking the tensioner is a crucial step (something you can’t do unless you remove the valve cover gasket), as shown in this video:


Once the tensioner is installed and locked you need to unlock the tensioner by releasing the hook and rotating the engine back a few degrees (it’ll make a clicking noise when it releases).

As Eden Prairie and Chanhassen’s Toyota and Lexus repair specialist, CARspec keeps the tensioner o-ring and valve cover gasket in stock and are able to perform this repair in about 2 hours. If you’ve got an oil leak on your Toyota give us a call!