Contemplating a second EGR cleaning

Did you do it personally last time? Or a shop did it?

 

I personally think so. I started getting misfires around 35k after my first cleaning and it was just a single clogged intake manifold runner (part of the EGR system), nothing else was that bad, but I cleaned it all and now I'm just gonna do it every other summer.

I would avoid any wiring harness mods or parts at the moment. At the very least inspect your intake manifold.

 

P0401 is an insufficient EGR flow code, so the mechanic thinking the valve is stuck open does not fill me with confidence.

Nonetheless, there is an updated valve available (and an ECM firmware update) and I don't suppose it would be a bad thing to have those, as the mechanic is proposing.

When the cleaning was last done, was the valve disassembled and inspected for a mashed ski jump? That (the mashed ski jump, not the inspection) can lead to P0401 codes (the valve ends up staying too far closed).

If there is that kind of problem with the valve, then replacing the valve should fix it, even if it's not exactly the problem the mechanic mentioned.

 

In the course of that it ran the oil low? Say low enough to turn on the low oil pressure light? Or?

 

If you can find the time, it's preferable to DIY. Especially if the alternative is a dealership. I did second time 'round last fall (wont divulge the kms, they'd have me committed...). This is how the cooler looked about the time I knocked off:

 

I bought my 2010 in 2017~ with 163k and around 183k, I did all the work to the EGR stuff and intake manifold, throttle body. The cooler was 100% clogged as far as I could tell. I only got it about 80-90% clean. I didn't do a good job on the valve, but it's been working fine. I didn't realize you could take it apart.

If they're putting a new valve on, might want to have them inspect everything in the least. They have to take all of the EGR stuff apart to get to it, iirc.

The low to high marks on the dipstick are 1.1qts, per manual. I think I just did a 7-8k oil change. I have garage issues and couldn't get it in there. I normally do 5k oil change and tire rotations. The only reason I let it get that bad is because I normally go through about 1qt ever 1000 miles. Then I've been towing a lot where I lose about 1/4 qt every time. It's doing a mix of burning it and the backside of cylinder 1 inbetween the exhaust manifold and timing cover is blowing out oil. I've not lost any coolant since owning the car, but have always had to top off the oil. Also I think I will never let the oil go that far again. Back to 5k, maybe even 3k since I tow so much.

 

So the dealership wants to do the wiring mods and use a non-stock EGR? It sounds kind of weird to me, it's not like the correct EGR is unobtainable is it? How much are they charging?

 

That's right. it's slightly taller, so they need to make a little more slack on the wiring harness. I believe there's an update to the software that should be done as well.

Not sure what the diff is. IIRC @ChapmanF has speculated it might be a mod to the "ski ramp" (his expression) in the cap. It's been found to get damaged.

I checked on ours (original), when I had it out last fall. Looked pristine, but only 96K kms.

 

I replaced the philips head screws on the EGR valve with stainless cap screws. In this picture, one side has been replaced with a cap screw.

Posted via the PriusChat mobile app.

 

C-in-DC recently posted a photo of an EGR valve whose insides don't look like the ones I've seen. I wonder if it might be our first picture of one of the updated ones:

Remember how the original one just has a long threaded valve pintle, and the stepper motor rotor threads onto it, so as the rotor rotates, the pintle is pushed out or back in.

This one seems to have a separate threaded plunger contained within the rotor, flat in shape, kept from rotating by a slot in an extra plastic disc locked by two tabs into the stator/housing. And this plunger just pushes on an independent, stubby, spring-loaded valve pintle.

The extra plastic disc may be what mostly accounts for the added height in the newer valve.

Maybe this design reduces heat transfer from the hot valve pintle to the threads (and ski jump) of the rotor. And/or, maybe it has a more robust stop designed in than the little nib that bears against the ski jump in the old one.

I wouldn't mind seeing more of what's in the newer valve—pop that disc out and let's see the rest!

 

I'd suggest checking and clearing the intake manifold EGR passages first, it you don't have time to tackle the cooler again yet. The manifold is easier, and at least as likely to be the problem.

Oil consumption unfortunately won't be affected by replacing the EGR valve.

No, 1.6 quarts (or 1.5 litres) per manual

 

that was the fake egr valve I bought on eBay manufactured by TINVHY. If I can’t return it I’ll likely mail it to @ChapmanF to test.

 

If you confirm the egr is good, I suggest checking gaskets on the in take side. The oem intake manifold gasket seems to wear more and more with removal and cleaning. I changed all the gaskets on that side of the engine to new felpro gaskets because it was cheaper than getting a smoke test done(throttle body, intake, egr pipe to manifold, pipe to egr valve. The only gaskets that looked worn were at the throttle body and intake manifold.