Timing chain tensioner leaking

It's not LEAKING, it's SEEPING. If it was leaking you'd see oil.
It seems to be a common thing for the Prius. And it "might" be the oil pressure switch.
It doesn't seem to be a huge problem and most don't seem to bother with it.
Mine is not leaking/seeping, at least I don't see any oil. You can inspect it for yourself, maybe wipe any
oil you may see off with a rag. Use a good flashlight and look around the front of the engine. The front being
the side facing the right front wheel, where the pulley is.

 

Most likely it's just seepage and you'll be fine for a long time. Take a look for yourself if you can figure out where it's at. Otherwise, the 2500 mile trip might be a good opportunity to monitor oil loss, carry an extra quart and check your dipstick every couple fill ups.

 

If not the oil pressure switch, it would be more likely the front crankshaft seal. And, this engine does not have a hydraulic timing chain tensioner. Even if it does, it would be an internal engine part. And, how did he determine that it was leaking and that there was slack in the timing chain.

 

It's not so much the "timing chain tensioner"; it's the timing chain cover, basically the whole end wall of the engine, on the passenger side. It's installed with myriad bolts, and uses a bead of liquid gasket all the way 'round, to keep the oil in. If that liquid gasket is compromised it can start to leak.

The quote of $250 to reseal is amazingly low, maybe suspiciously low. More typical is $1500~2000; it's not a trivial job. Hopefully it would not be a case where the quote suddenly escalates, once the car is on the hoist and half apart?

Take a look for yourself. Look down the passenger side from above, with a good light. Better: remove passenger side front tire, a couple of the plastic fasteners on the plastic panel at back of the wheel well, flex the panel back. If it's leaking it'll definitely be evident there.

If it's minor, consider just cleaning it and monitoring.

If you see nothing, you're being scammed.

 

Really? I thought there was a tensioner. 12:30 on the prius head gasket video shows what I thought we were talking about.

I bet ASRDogman may be right though, because the oil pressure switch on my car seems to be seeping and since (I thought) they were in a somewhat similar location it's probably easy to get them confused (besides the electrical connector).

As an aside (since the OP's question has pretty much been answered)... How does the oil pressure switch seal? Anyone ever replaced one? When you see the photos of the part and then look at it in car it almost looks like it's barely screwed in.

 

You're correct. There is a tensioner. It is, however, not hydraulic, and doesn't leak oil. Also, it can't be seen without removing the timing chain cover.

Most likely, as I said before, it's the oil sender or the front crankshaft seal. Doing what Mendel recommends and checking the area behind the harmonic balancer is a really good idea.

 

Oil pressure switch is a tapered fit. It's a "forced" sealed fit. What leaks is where the plastic meets the metal.
The plastic gets and and brittle. They are inexpensive and as simple as unplugging the wire, put the socket and ratchet
on it and unscrew it. Then screwing in the new one and installing the wire.
Screw it by hand first, then the socket, then there wrench. You just need to "snug" it up.
Carry your tools with you, drive the car for a mile or two, then check it. If it's leaking, snug it up.
I'm not sure which the Prius has, but some have an "o" ring and are not tapered.
I have not changed one a Prius, but I believe it's tricky to reach, but not bad. Take your time, NO hurry.

 

If it's the oil pressure switch leaking that'd be much preferable to the timing chain cover, a lot easier to resolve.

 

Thanks for the info guys, good stuff to know. I just peeked at it again and I don't think it's the oil pressure switch. The timing cover bolt just above it had the most oil on it, so maybe it is the timing chain cover. It hasn't grown and I don't get much oil loss so I'm not that worried.

 

Maybe the valve cover gasket is leaking?

 

welcome

it's not serious, ignore them

 

Yeah wipe the whole area clean, then check again in a few days, to see better where it's starting from.

 

Stop getting the oil changed at the dealer they use the crappiest oil and religiously overfill it.

Prove me wrong and check your oil after the car has sat for a few hours. I bet its way over the full line.

You really want to use the best synthetic oil you can given all its EGR issues.

I think other posters are right its probably leaking at the tining chain cover seen many threads about that Georgina is right its not the timing chain tensioner as they would have to take the valve cover off to check that.

Get a big piece of cardboard and park the engine over it to watch for oil leaks. And start checking the oil like its leaking. keep it at the full line always.

 

Rtv it yourself

 

If you're game I can post the instruction.

 

That's funny because I JUST downloaded the timing chain instructions you posted in another thread years ago. You are doing the lord's work good sir. If I had to do this in the distant future I might just say screw-it and just use black RTV as best I could.

I'm also still convinced you can get to the timing chain tensioner externally without removing the cover. Pretty sure I can see it, and the two 10mm bolts that hold it on. Do you have the instructions for the tensioner specifically?

 

Correct

 

Prove me wrong. Diagrams? Pictures? Part numbers?