Engine knocking, CEL, fouled plug, and lost coolant

Notice in the Luscious video she states it's making noise but the impeller is not moving.

I'm thinking you'd need to pull the pump to view whether or not the pump is operational. Flow movement at the bypass could simply be from pressurization from the bad head gasket. However, in your most recent posts you refer to pretty short trips and the Prius is fairly cold blooded with regard to warm-up. Very good chance you're not ever getting to closed loop. My thinking is that it's still unknown where you're at with water pump and t-stat functionality. Again, Mini VCI or VXdiag for Techstream would pay for itself many times over for you here.

Yes, the t-stat is directly off the back side of the engine casting where the water pump mounts. It's contained within the water inlet.

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It is my humble opinion that if an engine is not getting cooled properly, that all OP's issues will occur. First the head will swell, causing leaks into piston chambers, causing misfiring, causing blockage for proper air flow and causing comsumption of oil. Might have been the water pump as the main thing all along.

 

Have you tried cranking the heat full blast and see what happens? Do you have an obd 2 reader where you can monitor the coolant temp? Have you felt the hose off of the egr cooler to see how warm it is?

Keep us posted

 

Man, I hope you're right. 'Cause if you're wrong - driving it will make things a lot worse and fast... And I wouldn't personally use stop leak unless it was a bandaid fix and I was replacing that engine. They're known for clogging narrow coolant passages in the head.

I'd have a pressure test done ASAP to make sure that water pump and thermostat are working.
Maybe run it without the thermostat to see if the radiator heats up.

I think I read somewhere that a sign of a bad headgasket is if you take off the reservoir cap and run the engine the reservoir will boil over. Thankfully I haven't had the opportunity to test.

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When you blast the heat, does warm air come out? Is the car running rough? How is mpg? How many miles have you put on since the stop leak and coolant level has remained stable?

 

If the water pump is still pushing a little bit through and if your engine is Ok I wonder if removing the thermostat would help. If your pump is on it's last leg get you by until you can buy a new pump?

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How long of runs have you had it on to get the 150 miles since adding the stop leak? A lot of short trips? If you are getting heat when the car wants it, that is a good sign.

Do you have access to an OBD2 reader to check the engine temp? If the temp rises to 196 then stays stable between 190 and 196, the thermostat should be fine. But worth looking into.

 

congrats, thanks for keeping us posted!

 

What is it that you did to fix everything?

 

I suggest that you use a handheld instant read IR thermometer to determine the temperature of the radiator hoses. If you drive 40 miles one-way in the moderate Southern CA ambient air temp, the thermostat certainly should open. If you find the radiator remains cool, I would say it is likely the thermostat is stuck. I don't like the design where the thermostat is part of the black plastic thermostat cover. That plastic cover can deteriorate over time and the thermostat may be stuck partially closed.

m.wynn provided good photos of the thermostat and housing in his post #61 above.

That was the issue that I recently had with my Jaguar XK engine which also has a thermostat located within a black plastic cover. One of the tabs holding the thermostat to the cover broke, with the result that the thermostat remained partially closed. Although I did not have an overheat warning light, the outlet hose to the radiator measured around 210 degrees F. After replacing the thermostat and the cover, the temperature dropped down to 185-190 degrees F where it should be.

 

Sammy B my man! Thanks for posting this as I am in the exact boat as you. Gonna do all the things you did and cross my fingers that I can extract another few thousand miles out of my Prius.

 

Having code 302 misfire cylinder 2 on 2010 prius with 167K. OIl consumption and coolant low on 2 ocassions. Changed spark plugs and coil and replaced water pump. Still get noise on startup when cold.

 

Get a new engine at Hybrid pit and you'll be back on the road again

 

I've got the same issue. I have a 2010 Prius with 168K miles. I've replaced the water pump, spark plugs, and coils and now I'm getting cylinder 2 and 4 misfire. Rattling at start up. Any suggestions before I start looking for a new car which I would like to avoid if possible?

 

any coolant in the oil?