2010 Prius Blown Headgasket

Thanks so much for for posting all that information Mendel. I wound up diving more around the boards here and found the full manual posted on PriusChat, which was helpful to have but also quite annoying how corresponding removal/install portions where in completely different areas. Therefore, flipping back and forth from page to page was annoying while covering in grease/oil and trying not to screw up the laptop.


I did manage to replace the timing chain, sprockets, head gasket, and water pump. I spent extra time ensuring that the chain tensioner hook was released so that the chain wouldn't wind up jumping all over the place and skipping a tooth or two. It was released. But when starting up the vehicle up on maintenance mode to run the water pump I got a bit of small jolt before everything wound up firing smoothly and left the car running to test everything for about 10-15 minutes.

I then spent some time doing a test drive for 15 minutes and all was well. The next morning while driving I started getting a bit of hesitation out of the Prius while driving down the road and in low idles I would get some vibration from the car. Now, after driving about 10-20 miles I have a check engine light (P0401) which states its the EGR....

I have trouble believing it's the EGR because I cleaned the cooler and pipes like no other, and made sure to be able to see clear daylight through the whole system by using brake cleaner, oxiclean, and oven cleaner...So, I know those parts are clean. However, I am wondering if the EGR is really failing and needs to be replaced because of the P0401 code, or if the timing chain would be causing that issue....

Does anyone know if the timing chain being off one tooth or so would cause a P0401 code? I really don't want to disassemble the wiring and everything else just to remove the cover to inspect the timing chain marks, but feel I might have to go that route. However, if the CEL P0401 is solely the EGR than I would much rather replace that and go through those means than having more work of redoing the timing chain..

THanks for any insight again!

 

Earlier I forgot to mention the following...

The vehicle is throwing codes P0401 & P0403. I made sure to clean out the intake manifold including those little small holes that tend to get plugged up while doing the head gasket replacement...I made sure to install a catch can as well because of everyone's comments and actually seeing the ridiculous amount of oil and crude in air intake manifold from previous cleanings. EGR pipes were cleaned completely so no soot was left standing, the cooler was empty of crud by means of also using a compressor and blowing out the chunks that were hiding deep in the recesses. However, the only chemicals I used on the EGR valve itself were brake cleaner (on the inside where the plunger resides) in order to get that crud flushed out. I made sure not to spray the circuit or electrical component itself.


Would the EGR not opening/closing properly cause a small amount of vibration in the engine? Or am I still probably looking at an engine timing chain issue? I just put the car on maintaince mode again and stuck my head in the engine bay. Just a little bit of vibration is what I can sense (out of the norm) but I don't know if that's being caused by a now faulty EGR valve?

 

did you disassemble the EGR valve? I've heard reassemble can be a little tricky, how you screw the valve back in. @ChapmanF or @Raytheeagle may have ideas.

 

When reassembling the egr valve, you need to wind the spring down into the seat and put the black cap on to secure it.

Then the screws can be set and you're done.

I actuate the valve with the cap and spring off to ensure it moves freely. I guess you could check the magnets for damage while you're there, but the dozen or so I've had off, haven't seen any damage to the magnets.

 

I take it you didn't rotate the engine 2 times after installing the timing chain?
Then check that the timing marks line up?
It's always best to do that because if you are off a tooth, you can catch it.
And possibly prevent a bent valve if you are off more.

You can remove the black cover on the egr valve move the valve. Not sure if that is possible or not,
as I've not taken one apart. But you could take the valve off and apart and make sure it moves.

 

The screws are (I believe, @Raytheeagle might know) M5x16. Just in case they get mangled.

Snapshot of an Amazon offering:

 

Looks right .

@m.wynn made his own when the screw head became marred due to dissimilar materials of construction .

His solution works too.

 

Thanks so much for the feedback everyone. I'm not sure how the issue remedied itself, but I think the EGR valve may have been stuck in the closed/open position for some time and cleared itself up. Maybe some loose grit blew loose from the cooler and went in and caused a ruckus to the EGR. I reset the code and tried to see if the problem came back, but nothing so far. Crossing my fingers. Also, the timing chain issue may not have been one to concern myself with, as I feel all the extra steps I took did manage to have the chain tensioner seat correctly. The car is running smooth as butter now with no hiccups or hesitation. It's been a full week, so hopefully things stay on the up and up. Thanks for all the recommendations with the EGR and the checking of the timing chain inspection, you guys are amazing. Again all help and assistance is appreciated....

...Now I am off to trace a water leak in the hatchback that is letting water in the truck. If it's not one things it's another. First, the car head gasket went, then my neighbor's house caught on fire once I got the car fixed which put our place in jeopardy after the series of fires we had already burn through Oregon...Then the water heater goes out on the house, and my wife's phone took a crap. Things always seem to happen in waves. Hope ya'll are doing well. Be safe out there and God bless!

- Jay

 

Well, maybe you are just getting it all out of the way at once!
Hope things will be better for you!