Oil consumption at 136k miles - too high

Welcome to the club. I'm in a bit higher mileage then you are but this car has seen the dealership for every single maintenance that was required. My gas mileage of summer, down into the mid thirties, and it drinks oil. I have a similar thread that I started a few weeks ago but have recently found that all my spark plugs had oil on the threads. I have not been able to check compression due to the size of most adapters not fitting but I know the results will not be friendly. I will follow this thread and hopefully you come to a better computer that I have. Good luck.

 

change you PVC valve and hope for the best..theres videos on you tube that will show you where it is and how to get to it..

 

The miss might be Exhaust Gas Recirculation system related. The most accessible portion is this pipe, connecting the PCV to intake manifold. It has a flange at both ends. The EGR end is easily accessible. The intake manifold end is quite difficult to get at, obscured by piggybacking connections. But it can be done, just a pain.

Get that off and see how clogged it's getting, it'll be symptomatic of the the rest of the circuit is like. I think you can just see the pipe here, peeking through between inverter and air filter housing. The latter needs to come off for access.



Better pic, EGR end of pipe at centre:

 

Yeah, 3rd gen is the first to implement EGR, and a lot of owners are seeing clogging. Pretty much everyone who looks I guess, lol. To clean the whole thing is an involved chore, the cure might be worse than the disease. At least pulling off this pipe you can get an idea.

 

Hopefully changing the PCV valve works for you because it did not work for me. It's only about a $13 part of so and takes about 30 minutes worth of time.

 

Oh, egg-on-face: I meant to say Exhaust Gas Recirculation, EGR, not PCV, in my previous posts. Will fix.

 

That first picture is just off the net, but yeah ours is very clean. One thing that might help: I pushed these foam tubing pipe insulation pieces onto the seams along the junction of engine bay and fender. When you drop the hood this seals pretty much all the edges, whereas stock you've only got gaskets at the front and back. Also, I go over it with an old paint brush, a boa duster, then hit it with a leaf blower every so often. I'm a little nuts about it, lol. Plus, we're only around 56000 kms, garage parked.

 

A liter every 1000 miles is excessive. Do you know what the engine rpm is when you're driving at 85 mph? The 1.8L engine in the Gen 3 must be spinning slower than the 1.5L Gen 2. Nevertheless, it's a well known fact that OC increases as engine rpm increases. You should see a decrease in OC if you drove at 75 mph instead of 85 mph.

It's unfortunate that you have this problem with such low miles (for a Toyota). I hope you find a fix for it.

 

Toyota claimed 2200 RPM for the 1.8L at 120 km/hr, compared to 2500 for the 1.5.

I hope someone soon determines what the oil-guzzling 1.8s have in common in their history, so I can avoid it---if it's avoidable!

 

Isn't it obvious: dust and leaves in the engine bay.

 

One thing, and this continues to nag me: the pipe between EGR and intake manifold seems like the canary in the coal mine. The EGR valve proper is back a ways, and has coolant hoses connected. At the back end it connects to the exhaust manifold. That connection is (maybe) best accessed from the underside. At the other end, I suspect the intake manifold is prone to gunk build up too. This is the first Prius generation to have EGR I hear, and cleaning it seems a can of worms.

But yeah, check the pipe first, and at least you then have an idea of how bad it is.

There's some pictures and thoughts in this thread:

Prius III engine knocking at high torque low RPM (solved) | PriusChat

A wack of pics on the last page too.

There's another thread, but I'm having trouble finding it. By member Christian Cool, or something similar to that?

 

If you have oil on your spark plug threads it sounds like the spark plug tube seals are leaking. A new, valve cover gasket set will have the tubes seals included.

 

Because the EGR is cooled (thanks to the coolant hoses Mendel mentions in post #15) I'd doubt wrapping it would have much effect on condensing gunk.

Good luck, and let us know how it goes.

 

I've completely removed the EGR system and cleaned that including the EGR cooler in the past with no help with my oil burn problem. The PCV Valve is what is a 13 dollar part and took me about 30 minutes to replace. Neither changes fixed my oil burn issue.