EGR & Intake Manifold Clean Results

^ I was wondering about that plate, that the PCV valve mounts on; noticed it in @NutzAboutBolts intake manifold cleaning video. Looks like it's acting like a oil catch can?

 

Super helpful, thanks for posting this picture. I'll do it too when doing the egr overhaul in the next year or two (i'm near 90,000 miles now).
Questions:
does oil drain back to crankcase, or just sits trapped behind that plate?
any gaskets there?

 

I will be editing and uploading the EGR and cooler tomorrow evening.

 

You did all that fun and didn't invite anyone?

Maybe next time !

 

Lol, it was not fun at all, the engine was still hot so we used some thick gloves, the weather was hot so we were sweating the whole time in the garage, and some of the spots were hidden so it was hard for us to film what we wanted.

Well, the fun part was cleaning the EGR and EGR cooler with brake clean

Now, time for me to sleep so I can edit 2-3 hours tomorrow

 

What's the primary reason to take all the EGR stuff apart and clean it? Recover lost MPG? I have 136K on my 2010 and getting about 44 mpg mixed driving. Wondering if I need to add this to my list of to do's. Was going to just change the PCV and clean the throttle body but not bother taking apart the intake manifold and all the EGR stuff.

 

It keeps the engine running more efficiently. If the egr system gets clogged, combustion temps will get too hot and will damage engine in the long run

 

Yes, Toyota has told us a reason for the EGR system is to lower combustion temperatures preventing knock. This is how they get away with high efficiencies. The combustion temperatures are on the order of 600* C (a number I found google searching) while the EGR gas is around 100*C. The EGR gas, being already combusted and now inert, slightly quenches the fire inside of your engine. It's like spraying water on a fire. Knock is one of the biggest enemies to a combustion engine.

There is a safeguard to avoiding knock. It's called a knock sensor. The ECU will tune the ignition timing. Knock must occur before this happens.

It's worth mentioning that for every 10*C temperature rise a chemical reaction doubles in speed (Arrhenius equation). It wouldn't surprise me if this means the wear rate also doubles but I could be wrong.

 

Maybe I'll do the IM and the TB then and skip the EGR. I'm too lazy to do "huge pain" projects these days. But simple stuff with good returns I'll do.

 

I'm surprised that Toyota would tune the ECU on the ICE to potentially have any knock. I've heard of using water injection (M4GTS) or running E85 or methanol to lower cylinder temps and prevent knock in performance cars but never heard of the EGR system doing that.

What if you just run 93 octane instead of 87? I know it's more expensive but the car gets such good MPG compared to my other 93 octane gas guzzling cars I don't really care.

 

How clogged does it have to get before it causes damage? Is this is a common problem for high mileage examples that have never been cleaned? I doubt most Prius owners that are not knowledgeable or on the forums know to take apart an EGR system and clean it. I don't think I saw it on the service schedule from Toyota either.

BTW great youtube videos, very helpful for DIY'ers.

 

Toyota spec'd 87 octane for a reason. I'd speculate that the delayed combustion from 93 could prematurely wear out your exhaust valves and may not assuage the issue much. But, I'm not a combustion engineer.

Based on anecdotal evidence from these forums, without cleaning the cooler, your engine could last approximately 160k - 300k miles before catastrophic engine problems. It all depends on climates and usage.

Pixel XL ?

 

@NutzAboutBolts should be beavering away on the EGR video as we speak!

 

The EGR condition doesn't look to bad, for 120K+ miles? Maybe I'll never get around to all the fun, considering our low mileage. I've tried to raise the shadows a bit:



(OTOH: It's getting there, I guess. And maybe clogging accelerates.)

 

Assuming it's clogged. How many people have actually taken apart the systems to inspect at 100K+ miles? Did anyone recover any lost mpg or performance after cleaning the cooler/pipe/IM etc?

 

I don't know how many have cleaned their EGR cooler but I do know the IM cleaning was popular on here since it helped alleviate the startup "death rattle".

From my experience fixing the "death rattle" last month my cooler was plugged at 73k miles. I took it out and cleaned it after finding the pipe between EGR and IM had deposits.

I'll report my fuel economy at a later date.