Oil Catch Can, Eliminate that knock!

Would it be fair to say no knock in park or neutral; it's knocking only in drive?

 

NEW UPDATE FROM TODAY:

1. It still knocked badly. So badly that people standing outside the car were shocked.
2. The strangest part, it goes away after ECU transitions to Closed Loop Mode (when you cold start your vehicle, and you notice a 'change' in rpm after about 30 or so seconds which seems like ECU changed some parameters which I think is the ECU transition from OPEN to CLOSE loop)
3. I disconnected the OCC, just to see if it goes away, and HELL no! it doesn't so OCC is perfectly working fine with all the pipes.
4. It definitely isn't EGR. Why? cleaned it 3K miles ago and today I checked the EGR outlet pipe to manifold and it was extremely clean, no carbon, no deposits.
5. I was thinking it might be gas? Last time I filled it up it did feel strange, a bit louder engine, but it was the usual station I go to. May be a bad batch? So I went to the store. Put Octane Booster into the remaining fuel in tank and poured in Premium gas and filled it up. Damn, those Octane Boosters work great! I think may be 10~15 HP increase? upon hard acceleration I get Traction light because of so much torque, I love how cool these things are! and engine was smoother and quieter then before as well.
6. Now waiting for the car to get cooled down again to test.

P.S It's not transmission 100%, because I unplugged Cylinder 1 coil and same knocking occurred so it's definitely Air/Fuel mixture. But I still don't understand the pinging it makes if shifted to N, it's very light, can only be heard with hood opened. (Ignoring it for now)

Next Steps:
If premium gas + octane booster doesn't solve the knocking issue, I am gonna do these:
1. Still clean EGR + EGR Cooler. Maybe it's sticking which has nothing to do with how much clean it is, so I am gonna try that.
2. Clean Injectors, using carb spray and a 12v Battery.

If it still doesn't go away. I am DONE.

 

I'm losing track: has the intake manifold been completely cleaned, including the EGR passageways, one per intake port?

Also, no check engine light?

Did you disassemble the EGR valve when cleaning it, take the black cap off? This has lead to some issues: reassemble can apparently be tricky.

Did I mention leak-down test?

I'm thinking all this re-cleaning may be for nought: you may have "progressed" to head gasket failure. Do note: there are various ways the head gasket can fail, allowing various fluids/gasses to go where they shouldn't be going, and not all of the ways result in coolant level dropping.

 

No check engine light.
Manifold with all port intakes cleaned.
Haven't cleaned EGR yet as I cleaned it not long ago. Should I do that?

 

And do you think all this knocking can start appearing in a day? One day there was no knock and the next day it was blowing engine out.
If there's a head gasket failure how do I verify it? Plus there's no drop in coolant level.

I am disassembling, EGR right now, will show pictures.

 

If it's EGR, will blocking the EGR help? what if I block the EGR inlet?

 

Don't go there, lol. An EGR filled with carbon is basically a block. One thing (a properly functioning) EGR does is keep combustion chamber temps lower. The engineers are counting on EGR flow to keep the engine from overheating.

I could be wrong, but I really don't think it's the EGR directly causing the knocking. EGR clogging, and consequential combustion chamber temps climbing, may have caused the head gasket to start leaking though.

 

Actually the only thing I haven't done is EGR cleaning cause I just did it 3K miles ago. So what are you saying do it or don't do it? before I get to head gasket part?

It'd be really bad if it's a head gasket cause apart from the startup knocking, she feels so good. Excellent MPG, perfect pick up, no coolant decrease, no oil consumption, not even a quart and it'd be just so sad that she has a head gasket failure.

 

You've cleaned the full EGR circuit, including all the EGR passages in the intake manifold, 3K miles back? Then I don't see any sense in redoing it; there would be no clogging in such a short interval.

No warning lights?

Yeah I would try a leak-down test.

 

One last thing before I get down to Head Gasket, which I'll be doing shortly but why does the knocking go away if push the gas even a little bit? From last couple of days, I always start it in Maintenance Mode, so I can accelerate it on start up but as soon as I let the pedal go it knocks. If this doesn't point out to Fuel Injector, then I am going down to Head gasket

 

I think we need to clarify a few terms in this community... "knocking" and "pinging" (as used in the rest of gas engine world) are the same thing: detonation of the end gas following a normal ignition event. "Misfiring" is a failed ignition event. These two things are completely unrelated. It's true that a badly misfiring prius makes a "knocking sound" but this isn't knocking.

 

Very good point!

 

The knocking only at idle sounds like a strong clue, to what I'm not sure, out of my depth. Hopefully someone has a clue.

When you say "get down to Head Gasket", I hope you mean testing still, not just diving in. Leak-down test for sure. You can also test for evidence of carbon monoxide in coolant, there's a kit for that. And a boroscope through the spark plug holes may reveal something. If one cylinder head looks a lot cleaner than the rest (steam cleaned by coolant), or wet.

Google Eric the Car Guy Leak Down Test.

 

Dude. I just got all spark plugs and EGR out. Uploading pictures soon. I am gonna get done with this thing, I mean today. i am tired of it

 

And btw, all cylinders and all spark plugs are extremely clean and totally similar. I'll upload pics soon

 

Dude...?

 

After injector clean up using carb spray a 12V battery, and EGR cleaning, no knocking on startup!!!!
I am gonna keep testing it! Will update every one soon. And I can't emphasize on how bad the injectors were!
Their spray was fine but they were completely clogged with carbon deposits

 

Nifty! They were probably leaking some. The engine will probably run smoother too.

 

Yes exactly. Acceleration is insane now. I hardly recall having this much instantaneous acceleration ever!. But I think I messed up something lol, with Pedal fully pressed, engine's sound has been changed. Originally it was more sort of a "hmmm", now there's a "chic chic" with it maybe it's the injectors making this sound now? LOL Idk but whatever it is I am loving it! Probably it will return back to it's original sound in a few days. Anyway, I am too tired to hook up my phone to upload some photos. I'll do it tonight. I am letting it cool down again, so I can keep on testing. I have ordered a Leak Tester as well, but hopefully it won't come to that

 

LOL. I have got a few days off and this is the only time to experiment stuff