EGR & Intake Manifold Clean Results

With everything in in its usual place, if you spray stuff down the throttle body then you might get chemicals on the MAP sensor, which is apparently not great. If you unmounted the sensor from the IM first or had the TB off the IM then no issue, I would think.

 

Ok, thanks! I just put everything back together besides the windshield wiper assembly, when I started it up it ran rough for 2 seconds then smooth for about 10 seconds then rough for 2 seconds then smooth for about a minute before I shut her down. Is it normal to run like that for a second after this process? I just want to be sure it's good to go before I put the wipers back on.

 

Yeah some rough running is normal, yours is not bad. Our 2010 threw a fit for minutes on the first startup (and a code), and coughed on a couple more starts. The 2012 purred like a kitten. (It had less clogging to begin with, and I was extra careful to air out any carb cleaner.) Either way if you shut it down before it warms up then it likely *will* run rough on the next startup.

 

I figured I would share my experience for the sake of data collection and I have a couple questions for those with more experience. Thank you to @Raytheeagle @NutzAboutBolts and @Mendel Leisk among others for their informative posts throughout this forum.

I recently purchased a 2010 with 170k miles that had spent its entire life in California under 2 owners and had been routinely serviced at the stealership. It had some detonation issues so I promptly cleaned the entire EGR, throttle body, and intake systems, and replaced the PCV valve. (I didn't have the time to do the spark plugs or install an OCC) The EGR cooler was completely clogged. Water wouldn't pass through it. The throttle body had a pool of oil and water in it, maybe 100 cc's. The PCV valve was moving back and forth but not freely. The intake manifold was dirty with burnt oil and the EGR passages were completely clogged. I never saw a CEL but the work fixed all of my performance issues right away.

Some notes:

• I soaked the EGR cooler in a strong caustic soda solution for ~60 hours and it worked like a charm. I have access to this heavy duty stuff at work.
• Also I wasn't able to engage my EGR valve, even after cleaning. I had to get the car back on the road and the hardest work had been done so I put it back together and so far I am pleased with the results but can't help but worry that the EGR system isn't actually functioning. I'm pretty novice, so does anyone have an opinion whether I'd see the performance results if my EGR valve isn't actuating?
• I sort of assume the EGR vavle was never replaced under the warranty extension but I am considering asking the dealership to cover this replacement since they sold me a car with all of these other issues.

Now, after driving ~200 miles I've noticed a significant decrease in my coolant level. Is it safe to say my head gasket is blown?

 

Possible, but typically you lose some coolant during the EGR cleaning process, and refilling it requires multiple passes to burp out any air. Did you run it in maintenance mode (to force continuous running of the gas engine) while topping it off a few times?

 

You can also start the Prius as you normally would, but have the heat in "hi" and full blast for the fans.

Saves a chicken dance.

So there are a couple of options.

 

I did NOT

Does your oil look clear or is it “milky/cloudy”? I did NOT have a significant drop in coolant but I followed the instructions on here to the letter including the heater on high & car in maintenance mode. I also never threw any errors afterwards. You should have bought my car (it’s for sale) - I did all this work & then some and it’s completely documented on here for posterity

 

Bloody good data point.

 

Saw someone on the FB group post that if only people used Chevron gas the EGR System would never need cleaning...

 

That's all I ever use, guess I'm immune.

Another popular myth: just take it out on the highway and floor it occasionally, that'll clean it out.

One that just might work: buy a 4th gen. The revisions to 4th gen EGR amount to tacit admission of the 3rd gen EGR shortcomings.

 

I'm here to tell you that even then, that ain't enough .

I used that exclusively for the 50k miles between the egr circuit cleanses, and it was still filling up.

But top tier fuel gives you the best chance.

 

I still want to disassemble one to find out.

Maybe when we are allowed to leave our residences for social functions again.

 

I did run it in maintenance mode but only topped off the coolant once. I’ll keep an eye on it.

nope. Nice and clear.

 

Aloha!

Started EGR cooler project today. 2010 Prius with 157k miles.

Couple questions....

-see pic of connector below. Where does it connect to? It is under the air box and to right of intake manifold.

-big stud that passes through EGR valve to head will thread easily without valve in place, but won’t catch when valve is in place. Tried for 30 mins, any advice?

-rubber hoses were very hard to remove, but finally got them off. Is there anything I can use to lubricate hoses a bit to make installation easier?

BTW am installing newest versions of cooler and EGR valve, will clean the old ones and save for spares. Did new intake manifold and oil catch can a couple weeks ago should be all good after cooler/egr install. OCC had about 2 Tbl of oil in it after 1100 miles. Don’t think condensation is an issue here, 70F is as cold as it gets where I Iive!

Thanks for your help!

PEH



!

 

One thing I've used on hoses and bushing is 303 Aerospace Protectant. It softens older rubber, helping to keep it from cracking, and has no silicone. I usually spray or rub some on hoses before I attempt removal.

PEH, did you replace the PCV valve, along with your OCC install?

 

Maybe this:

Think I know the one you mean. I found it stiff going too. There's a long-winded instruction in the Repair Manual about temporary assembly of the valve and cooler, a sequence. I could NOT get my head around it, but suspect what they're driving at is that if you preassemble the valve and cooler, the tolerances may add up so that it's hard to get that last stud in. Assuming you've tightened everything at the cooler to exhaust manifold connection: loosen that connection slightly, try to get some play. And the underneath nut as well (that one you can actually just leave off, it's such a hassle to access). Basically loosen anything you've tightened so far, then try the problematic stud again.

 

I found that stud fought, all the way back in. Seemed @NutzAboutBolts had the same issue, mentioned something as he was reinstalling it.

 

I had this last night. I held a constant pressure on the EGR valve black cap towards the rear of the car and that gave me the slack to thread that stud all the way in before easing up.


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