Engine knocking, CEL, fouled plug, and lost coolant

Ok, sorry about that.

 

Definitely sounds like a head gasket.

With the amount of oil consumption and head gasket issue, I would look to source a used engine. They can be had for ~$1200-1500 and have 20-70 k miles on them.

Just make sure it is the 1.8 L engine. The Prius C 1.5L engine is also out there and is significantly less. One member a couple of months ago made that mistake.

Keep us posted.

 

It must be true, I read it on the internet!

The OP has stated that he has religiously done his own maintenance since new. Same degree of anonymity and cred as your opinion that the common Gen 3 engine issues are due to lack of upkeep. I believe Sammy B (he displays a reasonable level of mechanical aptitude) and I agree with the point of your post. This is an internet forum.

My point (with only internet forum cred to back it) in this thread is that head gasket failure is a Gen 3 issue. I include pistons/rings/EGR in my fantasy recall because I personally believe Toyota has fubar(ed) all with regard to the Gen 3 engine, upkeep maintenance aside.

In the last year or so there are several "confirmed" reports of head gasket failure and at least a handful of threads in which owners are chasing misfires unsuccessfully. Many of these are at a mileage that, although reasonably high, is not high at all with regard to Toyota. New plugs, musical coil packs, misfire at the same cylinder... Is an ECM/ignition issue the root problem for each one of these? Could be, but I'm not recalling any confirmation of this. I suspect the electric water pump needs to be replaced at a given interval on Gen 3, at least for those who go long-haul with their vehicles, and the OP has seemingly confirmed his water pump is dead. But I may be wrong and that's why I've started encouraging the latest confirmed failures to verify water pump status. If you search the Gen 2 forum, head gasket failure is a complete rarity. So even if Gen 2 owners do zero maintenance, the motors in general, are not burning coolant at twice the age and, at times, twice the mileage as the Gen 3's.

With the amount of both oil and coolant the car is burning, I'm surprised the plugs are even identifiable as such.

Scooby Doo laugh!!

Best of luck, Sammy B. At the risk of being a pain in the nice person, please verify if your water pump is dead or not.

 

I think ive heard something about if Coolant gets old or past its rated mileage that it turns into some kinda acid and eats head gaskets like its candy

 

I don't think so.
Looks like everything that can go wrong did do so in this car. Any issues with battery or ticking CV joints?
I understand that industry standard for car longevity is 150,000 miles. If Toyota shoots for 180,000, it's above standard.

 

You can do a simple compression check with the Prius in inspection mode:

Stuck piston control rings and clogged return holes are indeed the reason these engines move oil. If you're going to tackle the head gasket, you may as well fix your oil burning, too. I would do new rings for how cheap they are but they may free up and be fine. Then drill out factory return holes and reassemble. Ivan Temnykh does a great video here with a Corolla which should be a very similar process to Gen 3 Prius.

Mini VCI or even better, VXDiag VCX Nano for Techstream are brilliant chinese hacks for under $100. Mini VCI can be a tad buggy but VXDiag works as I would imagine the real deal does. I've got a solid amount of experience with both and can say you should for sure have one or the other. Pays for itself the first time you hook up.

You've got me really fired up about this project! Please take pics/video and be generous with the updates.

 

Looks packed. Might want to also pull off the egr valve and take a peak into the cooler.

When doing the intake manifold, ensure the egr inlet passages are clear as they will likely also be packed.

Keep the pics coming

 

One thing to also do if you are removing the intake manifold is to replace the PCV valve. Normally a lot tougher to do but a 5 minute job with the manifold off. Also a $7 part so cheap insurance.

 

What's that orange discoloration on the coil?
BTW, I believe the EGR should be routinely cleaned every 100000 miles.

 

As Ray points out, the EGR pipe is just one small portion of the entire EGR circuit. You will find the EGR ports in the intake manifold heavily clogged, imo. Also, the EGR valve and cooler are likely in need of cleaning, too, even if the car hasn't thrown P0401.

Not surprised the compression is similar across the cylinders. If you drop the oil pan and pop the pistons out, you'll very likely find all oil control rings similarly coked. Compression rings are likely similarly free.

Awesome story so far, keep on digging and snapping pics!! Not making light of your situation but it's great to see a tear down on a Gen 3 engine.

 

I wonder what's happening with high mileage cabs; seems like a crazy imposition: the EGR clogging is a "when", not an "if". Toyota should 'fess up on this.

 

If I were about to undertake what you will be, the $15 would be a worthwhile investment .

 

With pictures you hav posted ....my diagnose will be to go with good salvaged low miles engine....by time you repair so many things that burning coolant have done to your engine and contamination that was drawn back via egr will not be cost effective.....
I'm glad you have pictures inside of combustion chambers....
And one that show fluid inside is definitely a head gasket failed.....
There is also possible that you have hydro lock that have damaged piston rings and head valve.....
You definitely have stressed out crank and rod bearings with this type of leak
If you do decide to replace engine ....
You will need to replace O2 sensors.....
And have some good highway time right after to burn and blow out exhaust system

 

I hope this will not discourage you from learning if your budget allows....to replace engine and become better owner and have skills to figure a lot of DIY