Rough Start After Replacing EGR Valve

If it continues to be intermittent, you might want to use an Bluetooth OBDII reader and Torque app to see if you can monitor some of the cars sensors in real time. Also Long ago on here I read about some kind of issue with the intake manifold on Gen3 cars that created a rough running engine in some conditions. Not sure there was a recall, but I think someone got a replacement manifold at no charge. But like I said it was a long time ago, so not certain.

 

I hate to say it... ...... Headgasket. This is exactly what my sisters 2010 started doing. We tried everything all in a waste of time and money. Cylinder one has coolant very slowly leak into it at first, causing a misfire. My sister drove it like that for over a month until everytime time the engine stopped when it restarted it made that awful sound for longer. It started out as only happening over a nights sit, and in the morning making that sound when it was cold. I hope you problem isn't this, but unfortunately it's very common on the 3rd gen prius. My dad and I replaced her engine by ourselves with a low mile engine. Eventually the same thing will probably happen to the new engine. The hybrid battery is still going stong with almost 250k! It will outlive 2 prius engines

 

Welcome to Prius Chat .

If you only cleaned the egr pipe and swapped the egr valve, there is more work to be done.

The egr cooler and intake manifold also need attention to fully vet your situation .

Good luck and keep us posted .

 

Hoping it's not the head gasket symptoms that guy above mentioned... Sounds like you've been thru enough already!

 

Of course it's very hard to tell from a picture, BUT, that plug gap looks HUGE! ......

 

^ Yeah I'd concur: the cooler (the stainless steel contraption between the valve and the exhaust manifold) needs to be removed and cleaned. Watch @NutzAboutBolts video, #17 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

And this thread:

EGR & Intake Manifold Clean Results | PriusChat

 

Not sure why you replaced the purge valve when the codes are for misfire and lean condition...

I think swapping the plugs to check the misfire and cleaning the egr system would’ve suffice to see if there’s any other issues. Also checking the cylinder compression leak down test, so with a blown head gasket you should see air in the cooling system and bubbles in the radiator reservoir. Same with coolant pressure testing.

Let’s hope there’s no more issues with that.

 

Leak-down test?

Full disclosure: I've never done one, but apparently it's good for pinpointing what's leaking and where. It requires setting piston at TDC on compression stroke (I think, going from memory), then applying pressure into the spark plug hole, and seeing where air comes out.

 

You don't need to test anymore... you have a blown head gasket. The red text above comfirms that you're losing coolant, and where it's going. The only way the engine can lose coolant is through an external leak -- which you'd see puddled on the ground. Or by leaking into the combustion chamber via a compromised head gasket or cracked block -- and the compression test confirms you don't have a cracked block.

It's worse when you first start the engine because coolant has been allowed to slowly leak into the cylinder while the engine has sit idle. Then when it's started again, all that coolant that's accumulated in the cylinder is burned off and pushed out the tail pipe. The head gasket leak is small now, so the amount of coolant that's being introduced to the cylinder while the engine is running is quite small -- not enough to significantly affect the appearance of the exhaust after the first 10 seconds. It's also possible that as the engine heats up, thermal expansion is reducing the serverity of the head gasket leak.

If I were in your shoes, the first thing I'd do is clean the clogged EGR cooler -- since that's likely what caused the head gasket leak to begin with. Then I'd try one of the products that professes to fix a leaking head gasket. As Click & Clack from Car Talk used to say, "Go to the auto part store and look for a product with the word 'Miracle' in the name." Seriously though, there are "block seal" products that supposedly work on minor head gasket leaks. I've never used one, so can't recommend one. But do some research and see what comes up. The "correct" way to fix it is to pull the head and replace the gasket -- admittedly, that is a labor intensive endeavor. So the block sealer is kind of a Hail Marry, but it's worth a try because at this point you have nothing to lose.

Good luck... and keep us posted!

 

Replace the head gasket. Don't use the sealer. It will also seal the water passages in the radiator.
Unless you are going to replace the radiator, water pump, thermostat(which you should when replacing the head gasket),
hoses........
The small leak will turn to a large leak and it will end up bending a rod in the engine, and possibly brake a piston, maybe
throw something through the engine block.
It all depends how lucky you are.

 

Love this.

 

WOW! ....do I miss those guys! .....

 

So much this. Look at my pictures I have uploaded and that will show you exactly what the sealer will do. Three months from now you will be looking for an engine. That’s how long mine lasted with sealer.

 

"It all depends how lucky you are."
And I repeat:
Replace the head gasket. Don't use the sealer. It will also seal the water passages in the radiator.
Unless you are going to replace the radiator, water pump, thermostat(which you should when replacing the head gasket),
hoses........
The small leak will turn to a large leak and it will end up bending a rod in the engine, and possibly brake a piston, maybe
throw something through the engine block.

 

I dropped my 2013 off at the dealer today. In April they determined that it needed a new head gasket at 116K. They wouldn't do it under wtty as per Toyota. I've kept an eye on coolant, etc. And, yes I had cleaned the EGR system and recently put on an OCC.
I've been asking everyone I know who has one of these Prius's of their experiences regarding this problem. Most haven't heard of this problem yet. However, my contractors Prius is sitting in his yard for blowing white smoke and the dealer not helping.
Last week I finally caught up with a coworker with a nice 2012. He told me that last month he had headgasket as well as oil ring problems but his dealer said Toyota will cover the headgasket. So now he is using oil every month!
Today, at 127K miles, I called my dealer to ask them to reconsider their estimate. I was told to bring it in for retesting as Toyota has reevaluated this problem and he was pretty confident they would reconsider.
In short, see your dealer again if it has less than 150K and is covered under California emissions standards, which NJ may be(?)

 

There's a member here putting together a lawsuit and lawyer-ed up. He/she need numbers, you sound like a good case to go along.