My Prius is down 4 quarts of oil 9000 miles after oil change

I really think the pcv valve is installed on the block in the wrong location. Our prius (gen3) started burning the oil around 80k and I do all the maintenance and decided to put an oil catch can in place when I found engine oil in the throttle body. I was able to trace it to the pcv valve. 10k oci have been done since ownership of the car. I find about a tablespoon or two of oil in the reservoir @ 10k miles. All this oil being burned in the cylinder is then making its way into the egr cooler, egr valve, pipe and intake plenum.
I just bought a prius gen3 297k with a blown head gasket. Ripped it apart to find egr cooler 100% clogged, egr pipe 95% clogged, intake plenum with 3mil coated in carbon deposits, oil in the throttle body from pcv and pcv pipe 1/2 clogged with oil sludge. I thought I was working on a tdi The good news is, I did not break any parts or stripped anything upon disassembly. Block and heads are straight, valves for cylinder 1 and 2 intake need to be lapped. Took two days of soaking/cleaning and a pressure washer to flush the egr guts and intake plenum of the nasties. Im pretty sure the rings are seized from carbon deposits on the pistons, they are soaking in marvel mystery oil. Cross hatch pattern for the cylinders look good, camshafts look good. Just waiting for a head gasket and other parts to come in for the rebuild.
I was tempted to throw another engine in but am curious how long I can run this motor since most of the parts look pretty good. Original hv pack and motor. Not sure if it blew a head gasket because of failed water pump (will need to bypass to make sure it is functioning) or ????? new head bolts and head gasket are going in soon. It's rumored that gas prices might spike this summer.

 

My theory is plugged EGR causing HG failures. Fuel will go up as soon as dollar goes down.

 

Wow, this is the post I've been waiting for regarding a failed Gen 3 engine. Fantastic work!

One question it leaves unanswered in my mind is the "oil" in the throttle body. This is a topic of much debate here because it occurs in all Prius whether they burn oil or not. The most offered (and seemingly accepted) theory is that this is simply an atkinson, late valve close timing function of air/fuel mixture falling out of "suspension". I use "quotes" where I'm not really sure if terminology applies correctly...and with my limited intellect, probably doesn't.

Your EGR circuit sounds exactly as I would expect a 300k miles engine to look. The TDI comment is a great comparison as Toyota has seemingly designed failed with it to a similar level as VW has with theirs. I think the reality is these EGR's are mostly blocked by half of that mileage or well less, and the many reports from those investigative enough to chase symptoms of shuddery acceleration and cold start knocking confirms this. And as friendly_jacek states, increased combustion temps once the EGR isn't contributing to the intake may be the smoking gun behind the head gasket failures.

Your report of the block and head being straight is the second I've seen and good news for those inclined to want to throw in a new head gasket and clean up their EGR circuit of an otherwise sound engine. Water pump can easily be commanded on with Techstream or I'm guessing with an application of 12 volts to the contacts. Personally, at 300k I'd replace it, along with the water valve/t-stat. How bout a few pics of the pistons? Based on typical control ring coking of iterations of these engines for decades, I'm guessing the Marvel soak might not get it done. You may be digging the rings off and drilling or picking the return holes clear!

Thanks for checking in here and please update with the rest of the repair.

 

Clogged EGR = running LEAN. Running lean runs the engine hot blowing a heat gasket. I'm guessing that is what you mean. Now I have to check to see if I have a clogged cat as well. The car drove when I bought it, poured out white smoke and ran really rough. Found the puking oil/coolant mix on the dipstick. Just want to make sure when I put her back together that I resolve the issue.

 

Cylinder #1 (head gasket failure)marvel mystery oil is seeping past the rings from 2 days of soak while cylinders 2,3,4 are holding the oil. I have a trash bag covering the block to prevent debris from falling into engine. Pics of my girlfriends prius' oil catch can I made from a ball jar. Her car is running smooth @ 107k with this system in place. I may use a degreaser to break up the carbon from the rings. I used this heavy duty degreaser from harbor freight to clean the egr cooler and intake plenum, worked great. The marvel mystery oil is not breaking up the carbon, I'm testing it on the valves to right now with no luck. I may use this same degreaser to break up the carbon from the rings. With 300k on the motor, I am surprised to see very little wear. That is why I would like to see how it will run. I have a valve tool coming in the mail so I can remove the valves and lap them while replacing the valve guide seals. I'm not an auto mechanic by trade, more of a hobby. I have a ridgeline with 165k on the motor with an oil catch unit on board that burns 0% oil.

 

Looks like EGR cleaning is a required maintenance item now

SM-N900P ?

 

This is depressing the hell out of me. The lemon gen?

 

And Mendel just bought new wheels!

SM-N900P ?

 

Is there any reasonably practical way Toyota could fix this with a recall? Reroute the EGR intake point?

 

In all fairness, the motor has 300k miles on it. I think whatever lemon Toyota created, still went the distance

SM-N900P ?

 

got some close-ups or detailed description WHERE you put your catch can in-line?

 

Fantastic gas mileage, solid transmission and electrical system. I'll take the good with the bad. Engines usually burn up seals around 300k anyway. Can you image what kind of cluster f@#$ it would be if fca made a hybrid. Had a jeep, what a heep. I use to have a 2005 prius with 195k, I needed a truck for work and it sat for 2 months before I sold it and on the day the customer came to pick it up. The hybrid system went bad. The dealer wanted 2500$ to fix it. Priuschat and youtube helped me fix it for 30$ by replacing just the one bad cell. I am here to help with my findings good or bad.

 

@m.wynn and I just did his egr cooler swap this weekend. Also did a water pump swap and intake manifold cleaning. Videos to follow. They are SLOWLY uploading at my parents house though.

We did videos of the intake manifold removal, water pump removal and replacement and water pump run on techstream. Did not do an egr cooler video as it was all hands on deck when we were doing that, so no free hands available to hold the small he camera . But we got all 3 jobs done in under 4 hours .

Based on 2 cooler removals, pulling the cooler as a PM seems like a good idea. Doing it a second time with a knowledgeable Prius owner gave some insights to reduce time spent on the job:

• All work can be done from above the Prius with no need to go under the car
• Place a blanket or towel below the work area to catch any sockets or nuts that may drop (ask us how we know)
• Remove the windshield wiper cowling gives great access to the rear nuts on the egr cooler (Mike still had to ascend the car to get at the lower nut)
• Remove all nuts on the connections to the block for the egr cooler and valve
• Remove the studs connecting the cooler and valve to the block using a torx socket (#8 I believe)
• Leaving only the stud for the cooler support underneath the cooler connected to the block
• The valve and cooler can come out as one unit

When placing the new cooler and valve assembly back into line:

• Place the valve and cooler back on the lower stud support for the cooler that was left on the block
• Place the nut loose on the lower cooler support
• Replace the studs on the back side of the cooler
• Place the bolts on the back side of the cooler loose
• Connect egr pipe to intake manifold loosely
• Connect egr pipe to egr valve
• Tighten bolts on the egr pipe to intake manifold
• Tighten bolts from egr valve to egr pipe
• Tighten bolts on the back of the egr cooler to exhaust manifold
• Tighten bolt on bottom support of egr cooler

Videos to come .

Thanks to @m.wynn for the hospitality and opportunity to improve my knowledge .

 

Remove u shaped hose from pcv valve and intake plenum.
Install hose per diagram. The fittings are different sizes so you will have to modify them accordingly.

 

Keep the pics coming as you go through your work.

Some questions:

• Do you have Techstream?
• Were you going to check the water pump?
• Were you able to shine a light on one side of the egr cooler and NOT see any light on the opposing side?
• Did the previous owner share anything about the amount of oil it was consuming prior to your purchase?
• How long was it consuming coolant before you began your work?

Excellent project.

Keep the updates coming as it will help the community understand and improve our knowledge of what high mileage looks like on some of the components .

 

I have a 2010 I got in Nov 2009. It just turned 79,000 miles on it and runs great. I am not driving it as much as I use to. Up until three years ago the driving was mostly highway, now mostly city. I check the oil about every month. I get the oil and filter changed once a year now and have never seen any detectable use of oil. I have a friend that is a machinist and he has been telling me for years that since the manufactures have started using the 0 and 5 twenty oils his work has doubled.

Thanks I will start checking mine more often.
Barnabas

 

Turbo charged, high compression, high revving, diesel engines use oil catch systems because they have increased crank case pressure. This pressure pushes oil into the intercooler and intake plenums. Causing engines to burn oil and causing intake valves and egr systems to get gummed up. I also see direct injection problems as well. Some manufacturers are now offering catch can systems as factory option. It was on fords page last year for factory parts.

 

I'm jealous others weren't invited to this EGR party

SM-N900P ?

 

If anyone was in the Adirondack area of upstate NY, they were welcome to @m.wynn 's slice of paradise along the Hudson River . We even tried to get @bisco to make the 4 hour drive and get the once a month highway run completed in his PIP, but he declined.

June 24th in Nor Cal @Rebound will be doing the intake manifold cleaning at our meetup. Maybe we can convince him to do an egr swap with my original cooler I have cleaned now that the job can be done in under 4 hours.

Your welcome to make the drive up on that Saturday .

 

I do not have tech stream, I will youtube this. I have an obd2 bluetooth and dash command to pull codes.
Yes I will check the water pump. If the water pump fails, red triangle or cel?
Egr cooler was clogged 100% could not pass go, blow air or water through. Had to use cleaner and a pressure washer to clean it. It looks brand new now and all of the screens are clear.
I do not have any prior knowledge other than original motor and 2nd owner owned @ 30k. Courier service.
Coolant, do not know. It was 10% filled when I saw it. owner says car was smoking so he stopped driving it, bought a 2017 civic hatch.