clatter/shaking, CEL on, oil on 2 plugs & coils... diagnosis?

sounds like dirty egr sytem is clogged and worst case scenario blown headgasket

 

Stuck-shut PCV valve creating pressure in crankcase, forcing oil up past piston rings, and causing the whole thing to fight to rotate?

Search for those codes. One thread:

P0300 code and probable misfires | PriusChat

 

We’re you the one that replaced the plugs? If so, when was the last round of plug replacements? What torque was used?

 

Did you remove the new plugs to see what they look like?
I am going to assume the new plugs filed shortly after start up causing the engine to jump around because it is now out of balance.
If the above suggestions don't fix your problem I would do a leak down test on those two cylinders and my guess would be a blown head gasket. A simple compression test would be OK but I wouldn't know how to do one on a Prius because of it's unorthodox starting method.
Maybe someone knows.

 

How is the engine coolant level?

If plugs 2 and 3 were never tightened that would explain the oil as would valve cover gasket leaking into the plug wells. Any idea how much (if any) oil it burns? I'd assume at 240k miles it moves some oil.

 

I second the valve cover gasket leaking. Cleaning EGR and Intake manifold is necessary every 100k or less.

Pixel XL ?

 

Yeah, I almost think the head gasket is a foregone conclusion on this one...

 

I concur with those who noticed the oil in the plug wells above the plugs, wondering if the valve cover gasket could be leaking. That's a straightforward fix (relative to the other possibilities). I'd look into that (and maybe replacing the oil-soaked igniters?) and see how far that gets.

+1 on the leakdown test. Or, if you have Techstream, you can do a conventional compression test (you just tell Techstream to crank the engine for you). But because the leakdown method is quieter and the engine isn't cranking, you can actually hear where the air is going if there is significant leakage. You might hear it whooshing into the crankcase, or bubbling out the radiator if the head gasket is bad. Or it could reassure you that things are ok, beyond the oil in the plug wells.

-Chap

 

The leaks into the spark plug well might be caused by excess pressure in the camshaft area? Due in turn to PCV valve not working??

Still, those two oily plugs were nearly loose, maybe not torqued? Lots of variables.

 

A super-quick PCV test is to take hose-pinch pliers to the PCV hose while the engine is idling in inspection mode. If the valve is already plugged, this will have no effect.

The engine controls can complicate the test (if the ECM says "hey, RPM changed" and makes adjustments to compensate). I'm not sure "inspection mode" by itself is enough to keep that from happening. ISTR that somewhere there was a Toyota description of doing such a test, and how to set a mode where the ECM doesn't step right in, so you can tell what happens. I can't find it at the moment, though.

-Chap

 

Those are the "capillaries" from the EGR gallery, that runs across the intake manifold. Pretty much mandatory for EGR valve/cooler removal: watch @NutzAboutBolts video, pinned at top of 3rd gen maintenance sub-forum:

Nutz About Bolts Prius Maintenance Videos | PriusChat

At the beginning he references other videos (same location), some of which you've already done, but perhaps not the removal of the windshield wipers, motors, windshield cowl? This is pretty much a must for access.

Also, you for sure need an E8 Torx socket, to remove studs, and a ratchetting (and swivelling is nice too) 12 mm box wrench is handy, for reaching the back nuts behind cooler.

Brake cleaner will work for most everything, except the EGR cooler, where 5 or 6 hour long soaks in hot/saturated Oxi-Clean solution (plug one end, pour it in) are very effective.

Here's one thread on the subject of EGR cleaning, lots of info:

EGR & Intake Manifold Clean Results | PriusChat

I'll attach some Repair Manual excerpts:

 

Stable coolant level is good news but it's hard to not be concerned about the head gasket! It's possible the complete blockage of the intake manifold EGR ports is behind the misfires. Definitely proceed with the EGR valve and cooler, with the cooler being the main objective and biggest pain in the nice person to pull. Mendel's oxi soaks are indeed a way to clean the cooler to shiny new, but if pressed for time, emptying a few (or several if it's it's really plugged) cans of break cleaner through the cooler will do a plenty good enough job to achieve essentially complete flow. Since the car doesn't burn much, if any oil, the cooler may not be ridiculously plugged. I wouldn't think a little exterior oil "conditioning" would damage the coil packs internally, especially since you have a code for cylinder 4 but not 3. Who knows, though... If you decide to replace them, I'd recommend OEM Denso. Toyota's don't do well with aftermarket electrics, in my experience. I guess once the valve and cooler are clean, I'd be inclined to put it back together and see how it runs.

I would guess your pic of the valve cover is just excess gasket silicone from assembly, but again, who knows.

Pics of the exhaust manifold area aren't telling of anything to me. Transaxle is off to the driver side. I guess I'm not seeing what you're saying looks bent up. But really, the only codes the car is storing are engine misfire.

 

When the EGR system is cleaned thoroughly you'll see a boost in your fuel economy.

Pixel XL ?

 

I don't really know for sure. But it sure seems like if enough airflow was restricted, the car would run rough as hell.

I'd definitely pull the PCV valve, give it the shake test and blast it with Brakleen, too. Might be the original in there.

 

A dirty MAF generally produces low rough idle. One contaminated like yours, who knows.

Make sure the ends of your coils are clean and show no sign of carbon tracking especially if they have oil on them. The spark needs to go to the plug and not to ground.

 

@sukatoro

Where was the "MAF" sensor? Below the throttle body is the MAP sensor, mine was awash in oil/gunk when I investigated. I eventually sprayed it down with MAF cleaner, after using everything under the sun on it, it survived.

They are not cheap, btw.