Timing chain tensioner leak.

@The Critic may have some suggestions .

 

I was concerned about having the same problem, so I made sure to tighten those nuts up very tight, and one of them broke! It even broke the bolt attached to the timing cover!

If anyone has any ideas beyond buying a new timing chain cover, let me know...

 

On corollas timing tensioners should be replaced every 100000 miles due to the spring getting weak. I expect the same for priuses. The leak, however, is not related to that. On corollas, it is common practice to put a small bead of silicone gasket goo on the tensioner when installing. On Priuses the tensioner works exactly the same way so there should be no problem doing the same thing. Tighten to only lightly tight, wait a few hours for the goo to conform to the surface and harden some, and then tighten to moderately tight, as with all uses of silicone goo. Read the tube for directions.

In general, you should use silicone goo very moderately when sealing thiings. IF IT GOOPS OUT YOU USED TOO MUCH!!! What you see on the outside after clamping down a part usually happened on the inside as well, so pull it apart, clean it off and try again. You do not want a blob of it running around inside your engine. But used sensibly it is safe. Most shade tree mechanics think more is better, which is not at all true, so please heed the warning about using too much. Almost always you use less than 1mm or 1 / 16th of an inch thick, and often even less, and you do not need to cover the entire surrface you want to seal.

 

Any particular product you prefer? Link?