Car knocking, changed spark plugs, problem persists

Jacob, I am battling with a head gasket failure in SWMBO's 2010 w/ almost 250K miles. Over the last 2 1/2- 3 months, I have gone thru over 2 gallons of coolant. There is no direct evidence of coolant in the oil, but I have found a slightly milky coating on the mid part of the dipshtick. There is no leak anywhere, but it does have the sickly sweet smell if you are behind it, and I followed her and saw what appeared to be steam from the exhaust about the time that the stumble would appear. The CEL has been on most of the time, sometimes going off of 3-4 days at a time. My solution will be a full transplant of a 2016 engine, so I guess we will then end up with a hybrid hybrid. I was planning to do it over the weekend, but SWMBO broke a bone in her ankle, so that one went out the window. Next launch window opens at midnite Tuesday, so we shall see.

 

I'm $140 into my HG repair so far. It's a super low cost gamble before dropping $1,000+ for a newer motor.

 

^ Easier too.

Editorial: SWMBO = She Who Must Be Obeyed.

 

Saved some from googling that.

 

Yeah, but $1600 for an engine that hasn't even made it to it's first oil change is hard to pass up...

 

How in the world are you doing this repair properly for only $140?

I just ordered all of the parts for mine and I am at $470 before adding the cost of the machine shop work.

My parts included:
- Engine Overhaul Gasket Kit (04111-37313) from Toyota
- 10 new head bolts from Toyota
- 1 tube of fipg
- Thermostat from Toyota
- Spark Plugs (Denso))
- 2 gal of Toyota SLL equivalent 50/50 coolant
- 5 qt of 0W20 synthetic oil
- Oil Filter and Drain Plug Gasket

 

The full gasket kit goes way beyond head gasket, encompasses pretty much every gasket and seal on the engine. The valve guides are included, I think. Are you doing those? Probably you can use 50%, but still.

The head bolts can be reused, if they still meet the measurement specs (outlined in Repair Manual, can post).

Thermostat and spark plug replacement is good idea, but coincidental.

Coolant and oil change supplies are needed in either case.

 

It includes all of the o-rings inside the timing cover, water pump gasket, valve cover gasket, intake/exhaust manifold gasket, egr cooler gaskets, etc. All of which are items that should be replaced.

Coolant usually fouls spark plugs. Thermostat is a must to prevent the likelihood of overheating due to a failure.

 

The block tester is not always accurate. If your coolant has turned a darker color, it is most likely due to contamination from combustion gasses.

If you want a conclusive answer, I recommend performing a leakdown test. But based on everything you posted, your problem is most likely a headgasket failure.

 

I've had mine out and reinstalled a couple of times, no problems.

 

I don't see why. I did put a little the first time, then started reading about it, wiped them off as well as I could leaving small remnant in thread grooves. I'm not going to touch them again until replacement time, and will probably just go dry threads this time; anti-seize does kind of mess up the torque spec, which is based on dry threads.

 

I have gone through well over 1 gallon if not up to 2 gallons of coolant so far, with zero evidence in the oil, and very few (if any) of the head gasket victims have had much if any evidence in the oil. It isn't a severe leakage as if it was there would be widespread hydrolocking along with coolant system over pressurization. it seems that it just losing enough to temporarily foul the plugs and then clear out and run fine. If this was a regular gasoline engine, it probably would not start but the hybrid drive spins the engine so fast and the low compression allows it to spin over enough to clear itself. When the head is pulled you will find one piston top that has been remarkably cleaned by the steam process inside the cylinder.

What part of NC?

 

Mentioned early on by @Raytheeagle , then kinda shouldered to the back of the room: EGR clogging may be instrumental in these head gasket failures. It's a new-to-third-gen component, that invariably "goes off" over time, and it's imperative that it be flowing air well, or engine temps will climb dramatically. And that unduly stresses the engine block, cylinder head, bolts and head gasket.

 

Mine is sporadic. For some reason it was much worse while we were in Florida. I check it twice a week and some times I don't add any for 2-3 weeks, then other times I lose over a quart in 2 - 3 days.

BTW, I think you are thinking about Pilot Mountain. Our Pilot is 3 miles north of US 64 just before Zebulon / Wake county line.

 

Any new updates my Prius also have the same issue need coolant every week and knocking when I try accelerate from stop to 15 miles/hour and also starting the engine and goes away after 2 -3 sec now the check engine light is on and I went to see the code is the cylinder miss fire. The service guy ask me to replace the sparkplug and the coil my car mileage is only 99k should I do it. Thanks for all your help