EGR & Intake Manifold Clean Results

I left the tin can there for the new owner.

I’ll have to check in to see if they took my advice.

But agreed, you can access it relatively easy from above.

 

Someone else with a low mounted Moroso can, put an extra NPT spigot where the drain tap is supposed to be, pushed some fuel line onto it, ran it along to an opening in the engine underpanel, and there pushed on original tap and spigot.

Still, I'm under there, take the whole panel off every six months for oil change, so no big deal for me.

Yeah I guess if you know them, and keep in touch. Thinking that I might be trading in some day, I purchased an additional PCV hose, keep it in the car. You could cheap out, just put the cut hose back together with a barb splice, but I wanted to keep it kosher. Maybe the day will never come though. Cargo cult again...

 

I bought a spare hose for the same reason .

And I used it .

Maybe not so cargo cultish after all.

 

I went through every part of the egr system yesterday and all seemed well (as it should, since it was just cleaned). Everything is free and clear with no build up at all. I did install new egr gaskets that were left over from the gasket kit when I did the head gasket. I also shortened a section of hose from my catch can to intake manifold (there was a potential pinch point that should be cleared up now). I cleared the P0401 code and have only taken one very short trip and one longer trip since then. No pending codes yet. I won't be driving much today, but will update as I do in the next few days and I'll probably do the egr step test on Techstream this week to verify operation and MAP sensor readings.

 

Well, I'm chasing the code once again. P0401 came up pending on my drive home this morning. It has to be either the egr valve or the MAP sensor; there's no other explanation that I can think of. I'll run the test on Techstream, but since the valve was functioning properly last time I did it, I'm betting the MAP sensor is the culprit.

Quick Update: Ran through the egr step test in Techstream and idle got very choppy before and at step 16, but then as I kept going it evened back out. I stopped at step 30 which it seemed to hold just fine with a normal idle. MAP value started at 5psi (step 0) and went to 6psi by step 16, then as I continued moving up it came back down to 5psi. I'm very confident this is abnormal. Idle should continue to worsen with step increase and MAP values should continue to increase. Not sure which part is at fault here between the egr valve and MAP sensor, but I will find out and report back.

 

Put a new egr valve on yesterday and have taken about 4-5 drives with no codes! As badly as I wanted to fix the issue without spending money, a new egr valve was what it took. Hopefully I'll be set till I decide to clean the system again!

 

Mind investigating the old valve to look for defects or the cause?

Just curious what actually failed that caused the computer to not think the egr valve was working. This would include removal of the black cap and look at:

• Spring
• Windings
• Plunger
• Magnet
• Any debris or impingement

Thanks for circling back to help the next guy out as well as our knowledge base.

 

Yes, I absolutely will and can post pictures if I find anything out. I've taken it apart numerous times in the past and never did find anything out of the ordinary.

 

Pictures can help those of us that have taken it apart a time or 3 help with anything out of the ordinary.

The more pics, the better.

 

Just finished taking some picures. I'll be curious to see what those of you that have seen lots of these have to say. The few things that I noticed were:

1) There appear to be some small, random scratches on the magnet (hard to pick up on camera but circled in yellow)
2) Black plastic magnet housing had some black wear spots on inside of it
3) Inside top of magnet seemed scratched or possibly broken. It does screw in and out as it should and will tighten down as well.

Does any of this seem normal or likely to cause failure?

As a side note, I have gone through plenty of drive cycles with the new egr valve and am P0401 free

 

The picture of the upper section of the magnet looks damaged and a piece is missing.

• Could this have caused the issues: sure
• Does this look like the other: probably not
• Would you pull off the cap of the installed one for comparison: hopefully

Thanks for the shots and glad the issue is resolved.

 

I assume the piece that's missing isn't the spring? I left that out because it was unremarkable. I'll try to pull the cap off in the near future for comparison, but I'm enjoying leaving the hood closed for now

 

G'day guys and gals!
This is my first post.

Firstly I would like to give a huge thanks to everyone on here sharing their experiences and very helpful tips and tricks. A special shout out to NutzAboutBolts for the incredible YouTube videos, could not have done any of this without you. Also to Mendel Leisk, Raytheeagle and Mjoo for your insightful input!

I went all out for my first real attempt under the hood. Previously I had only changed some brakes and wheel hub assemblies.
After watching all NutzAboutBolts videos (many many times over) and reading all these forums I decided to tackle all these related tasks at once.
I removed and cleaned the EGR cooler assembly, intake manifold, throttle body, replaced PCV valve, drained coolant completely before removing hoses, oil change, inverter coolant change, transmission fluid change and will do spark plugs (held off on them until I can confirm proper operation of engine ).

I allocated 2 full days, I am now going into day 5...
Manifold and EGR cooler being the main culprits of this.

Last night I got it all back together, filled both coolant reservoirs and did the inverter bleed first without starting the ICE. This worked well.
I then crossed my fingers and started car in Maintenance mode to work on bleeding the engine coolant. (When I filled it I used the bleed valve til some came out then closed it.)
The ICE started right up which made me happy but it had terrible engine knocking, I chickened out after 20 seconds and shut it off. I could not see any check engine light but I may have missed it. After a few minutes I tried again and it started much nicer with no knocking. I left it going for a few minutes then went inside. I heard it make a strange noise (possibly revving) and went out to check and it appeared to be smoking quite a bit from exhaust! I shut it off again.
After several minutes I tried again, it seemed much more settled and I realized the 'smoke' could be more from freezing air than the car necessarily. I ran it for about 20 minutes and the fans never activated, no sign of movement in the coolant reservoir. I had the heat set to full, fan on low and AC off. The check engine light also came on by the 3rd start.
Some things to note, the engine was sounding quite rough and noisy during 3rd run. No knocking though as happened when I first turned it on.
If it idles OK today, I will go to Advanced Auto and get the CEL scanned and update.

If any of you could give me some advice before that, it would be appreciated! I noted several people performed the EGR clean and got the CEL that then went away on it's own after several runs. I am hoping this is the case.

Every part was spotless and completely dry by the time I reinstalled, besides the EGR valve which I could not get all deposits off the valve stem inside. I partially stripped the heads the the screws to remove the plastic cover of valve, I could not get it off so cannot confirm proper function of valve. I have no impact tool to remove it. If the valve needs replacing, can it be romoved from the cooler WITHOUT taking the cooler off?? I could not tell if it would be possible with access to bolts.

Should I unplug EGR valve to see if car idles smoother?
I read that electronic throttle bodies may need relearning. Could this be causing issues? I unplugged it and removed before cleaning.

I also removed and cleaned both MAF and MAP sensors with MAF cleaner. I did not touch, just sprayed thoroughly.

Should I just leave car running in maintenance mode for 20-30 minutes today with coolant cap off to ensure it is bled properly? I cannot access hoses to squeeze. I have probably 1-2 qts of coolant left over from 2 gallons after filling both reservoirs.

I have more questions but I think this is long enough for my first post...! Thank you for anyone who takes the time to read this and especially to anyone with guidance!

 

Toyota really should have used some hex head style hold-down screws on the EGR valve cap. I threw in the towel (even with an impact driver), found I could clean just fine without removal of that cap. Might have kept me out of trouble too: I hate it when you take a lid off something and a spring shoots out, for instance.

Anyway, judging from the "after" pictures, I think you're fine. Maybe your woes are due to the coolant changes? You did the engine and the inverter?

Maybe @mjoo, @Raytheeagle , @NutzAboutBolts , @The Critic , @Rebound and all have ideas?

How many miles did it take to get like this:



Were there no warning lights on the dash? If so, that's a total fail for Toyota.

 

I would first get the code before moving forward, your guess is as good as ours until the code is read and then proceed to identify what went wrong. Sometimes, if it’s your first time doing a major service, you can tend to forget to plug certain things back. It happens, so before guessing what went wrong, get the code and go from there.

 

Thanks guys for your replies!

The next day I started her up and no check engine light! I think it's idling about the same as before I performed the service. Initial start up of the ICE though has an initial knocking very briefly. This may go away.

Sorry I did not mention, it's a 2010 with 216k Miles! I've had the car since 175k.

Mendel: I completely agree about the hex head!

I'm confident now that both coolants were bled correctly. I ran it in idle the next day again until the thermostat obviously opened as the engine coolant was hot.

I agree, it is crazy that this has 216k miles, the EGR looks like this and there were NO warning lights! I have read also that if they leak oil for any reason that you wont get an oil warning light until it's almost too late unless you shut off car immediately. That to me is insane!

NutzAboutBolts: I will go get the light checked this week out of curiosity and to update you (although it is now out). I understand it's not very helpful without me providing the code. I was a little nervous to drive it at that point so was just after some initial feedback considering the symptoms I was having. Thanks for your reply. And thank you once again for your fantastic videos! I could not have done it without you and its given me a lot of confidence to tackle other tasks.

Considering it was idling much better with no CEL, I went ahead and changed the spark plugs before putting the wipers back on. Was disappointed to see oil on the spark plugs of both 2 and 4.
I have been burning some oil, it seems very sporadic. Usually not more than 1 at per 3-4k miles. Is it safe to say the reason for the oil on plugs is from the poorly designed piston rings on the '10 and '11 model? The plugs had around 100k on them.

 

I checked all those. In my previous reply, I stated that all appears to be working now. Thank you for your suggestion.

 

My Prius was getting tremors at low ICE revs (while throwing codes 0103 and 0303). Despite replacing spark plugs and swapping the coil of the cylinder that was misfiring, there was no improvement. Based on a suggestion here, I disconnected the EGR valve connector, which made the car immediately run smooth, with a lot more power. This convinced me to do the full Intake Manifold and EGR system cleaning. After doing the cleaning (without draining the coolant), the car started as normal. It did throw code P106a, which did resolve itself the next time I drove the car.

 

Regarding EGR cleaning and coolant drains, I took a "hybrid" approach: drained 2 liters from the rad before starting, and that was enough to drop the coolant level completely below the EGR circuit. When lifting off the EGR there's just a few tablespoons of coolant at the lower/back corner: lifted it off without tipping (once I twigged that some was trapped), and added to the previous drain.

When everything reassembled, I poured the coolant back into the reservoir. I also left the coolant bleed bolt open while doing this, till coolant started coming out, and burped the larger coolant pipes while pouring it in. 2012 and onward model year nix the bleed bolt, but I believe temporarily pulling off the topmost coolant hose while pouring could work similarly.

The coolant ended up slightly high in the reservoir, stabilized per usual with a day or two driving.