2009 Prius - desludge?

Hey guys, I have gen2 that I've had since it had 20k on the clock and it just rolled 180k. Its been so so solid needing nothing but oil, tires, and blades for about 100k. It had a recall to change the inverter pump but other than that, its never been in the shop.

I've change oil myself at about 5k. At about 150k or so, it started doing this shuddering like it was missing on a cylinder sometimes when the cars was coming to stop and cutting off the ice. Its like it didn't want to die and instead missed for a few seconds. No check enige light or miss codes. This was not happening all the time and I didn't really nail what particular circumstance led to it, although it seemed to happen more when I was low on gas. It progressed though to a kind of knocking that sounded like it threw a rod. I ended up changing the plugs and ignitors as a shotgun approach and the problem actually did seem to help. It still happened some but not as much and less fierce.

Soo.. At about 170k, I was coming down my driveway which is very steep (like 45 degree), and the red triangle came on. I dropped the oil and it was maybe a quart of black super thick nasty oil. Changed it about a 1000 miles ago and its definetley burned some. Maybe a quart? Ill change it again an be more scientific about it.

Last night I pulled the injectors to clean them and there was oil in the injector electrical connectors, and it looks like oil maybe had been leaking out of the oil cap or maybe from valvle cover. Cleaned it well and will see what it looks like after some miles but when I had the injectors out, I could see sludge in there. Should I go ahead and pull the valve cover for inspection?

The car is still running fine with no CEL? I'm wondering of the vlavles and/or rings are sludged and that's what's been behind the shuddering. Engine may be borked tho from the super low oil event. Looking for advice.

 

Also forgot that night I also changed the pcv (that was original with 180k miles on it) and cleaned the throttle body and maf. Small amount of oil pooled in throttle body. Not much tho. Few mils.

 

Is the air throat where the maf is located? I did clean that and the maf really well with maf cleaner.

 

Yea it gets a lot of use. I'm a consultant and drive this thing all over. Around 33k/year. I was thinking about maybe a piston soak but wonder if I should tear the valve cover off for a better look. Anyone done it? I have another vehicle to drive if the pri needs to be down for a few.

 

Good tips. For sure the atf fluid has never been changed and i bet you're right on the recycled inverter coolant fluid. I'll read up and change those.

Now that I look back objectively, I've really done the bare minimum maintenance as needed like an nice person. The original drive belt was just changed at 175k. I happened to notice how frighteningly bad it was cracked when I was changing the oil. Yikes. I'll post some pics of this champion of all belts later.

I changed the front rotors and pads at 150k because the rotors were rusted out pretty bad. I shit you not, the pads still had some life on them. I put all new toyota brand brake parks back on because they're obviously designed well and worh the money. Also changed the front struts.

The pri is paid off and still very nice to drive so I'd actually consider replacing the engine if it had to be done. My girls not ready for scrap yard just yet!

 

Yes the coolant is low in the radiator. Don't see any looking down the neck. No signs of coolant leaking so I guess that implies the head gasket blew? I listened to it run in inspection mode and it didn't sound noticeably loud to me. I took some video and I'll upload it. I think I'll change the oil again and strain what comes out to see if there's any sign of components coming apart. Damn!

 

Car also smokes white smoke.

 

I have more good news. I drained the oil that's only been in for about 1,000 miles and it was really thin and bubbly. Definitely has coolant in it. I strained it through a screen and didn't find any metal debris. I also pulled the plugs and looked at them. They are prerry grey.white and all four plugs are wet with oil on the threads. (I took some pics). I can see some sludgey buildup on the pistons when I take a pic down the spark plug holes with my phone.

With all this would you definitely recommend replacing the engine at this point? I would rather just get on with it if it's warranted rather that drive it until it fails. I found some engines available a few hours from me in Columbus, OH with under 100k for $400 to $500. One says 79k for $550. Would I be able to get a decent idea if the motor has been maintained by peeking in the spark plug holes and injector holes with a small 5mm inspection cam? Anything else key to look for on an already removed engine?

 

anything else that should be done why the engine is out that would normally be a huge pain? I want to keep the car for a while. Also, any tips on checking out used engines that have already been removed?