Thanks to everyone who has previously posted on this subject and unknowingly guided me this far. Okay, here is the short Version, 2010, 240K miles, knock started in slow traffic on I-95. I went to get it, knock at start up for 8-10 seconds then cleared up. Towed home. Codes P0301 thru 04.... Will occasionally do it when feathering the fuel maintaining a following distance and immediately clears at 100% throttle, Cleaned EGR cooler (totally blocked up) Replaced EGR valve, Cleaned stainless pipe to intake Started fine, fine on test drive up to triple digits. Next morning, knock at start up, same codes.. Removed intake, bottom of throttle body looked like caramel goo along with large chamber and runners. Cleaned all with brake cleaner, pressure washer, and carb cleaner paying special attention to EGR cavity and ports. Still knocked at start up, same codes, Changed plugs, 2 of them looked pretty crappy, same result I was following her in cool conditions and looked like more exhaust smoke than everybody else........... So great wizards of all thingies Prius, Now where I go? Coil packs are about 2 years old, but may still be under warranty (Advance Auto), Recent A/F and coolant changes with no loss, Is using oil, about 2 quarts in 5K change interval, switched to Full Syn 5W30 about a year ago. I've read the info on intake replacement, if I have to go that route, are the aftermarket ones upgraded also? I have read about adding the oil catch can into the PCV, will that be of benefit? Thanks for the guidance I am about to receive.
I'd try some strong injector cleaner and OCC first. Have you heard of piston soaks? Could help your oil burning and rough running. Pixel XL ?
That didn't happen overnight; has probably been near-blocked for the last 50K or more? Which means the engine is running overly hot, for some time. Is the engine coolant level staying steady? Start with compression and leak-down tests?
I'm pretty sure your head gasket is shot, that's why your 2 plugs look really bad. And the smoke coming out of the pipes.... There was a member that remedied the tough starts, by replacing a faulty head gasket.
TY, At 240K miles, would I be better off replacing the motor if I can get a good used one (around 100K miles)?
Some have had luck with a high quality ceramic based head gasket sealant that gets added to the coolant. There is a procedure to activate it. I'll ask my local mileage record setting Prius buds for the brand. It may buy you time. I doubt that it is a permanent fix. Why would you buy a 100k mi used engine, with an unknown history, when you know the head gasket is going to fail in it in XX miles? I would try a long piston soak and see if it improves the oil consumption, along with this coolant sealing treatment and see how it behaves. Keep an eye on your coolant reservoir, yo..... Then if those things really do help, start using full synthetic oil and stop being cheap with the oil, yo.
A couple of priuschat members have put in 4th gen Prius engines. There's plenty of low miles engines from crashes, and there's been improvements to the pistons and rings. This guy uses the complete engine, but retains third gen intake and exhaust manifolds, and 3rd gen EGR as well. Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v | PriusChat
Thanks everyone. I'm using synthetic oil, just upped the viscosity, and I am having to replace anti-freeze. I came to the realization that the engine was toasted, headed for extra crisp just before we started a trip to Florida. We tow the Prius so we will have transportation while camped, so it is still being used as a local driver. I didn't want everyone to think I was a drive by poster as so many are on my favorite RV forum. I'll check out the thread on the Gen4 engine swap.
