EGR & Intake Manifold Clean Results

Our 2011 was making some loud clanking noise, especially upon start and low speeds. O'Reillys scanner said code PO401, misfire and EGR. We brought it to the Toyota dealership and they diagnosed random cylinder misfire due to severely cartooned up intake manifold causing EGR valve to stick open. The dealership is closed due to coronavirus, so we brought it to a trusted local mechanic. He cleaned the intake and cooler/pipe, and replaced the EGR valve; said everything was pretty cartooned up! With 238,000 miles he said we could save $ by seeing if we could get another 100,000+ by not replacing the intake manifold.
We drove off, happy that the repair was half the estimate from Toyota.
However... we noticed another rattle at low speeds, and the check engine light came on about 20 miles away from the local mechanic's. Called him and he said to drive it another day or two and see if it doesn't burn off and run smoother. He said spark plugs may need replacement (they have 114,000 miles on last replacement).
Advise please-

 

Pretty cartooned up.

Is that a spell check error or has the engine just gone Looney Toons on you?

 

LOL. yes, it was spellcheck. It was coated with carbon!

 

Forgot to mention that I bought a new stud/nut for EGR, and 2 new studs/nuts for exhaust pipe connection at rear. Figured with new egr cooler and new egr valve it would be tidier. Originals were pretty ugly. Also I always get a couple extra of everything (gaskets, bolts, nuts, washers) so I can drop some in engine compartment!

The big stud on egr threaded on try #247. No hoses attached, no bolts attached, just the two studs at exhaust (without nuts). Also, left off the bottom mounting nut.

Found the missing connector, went in side of intake manifold.

Did a coolant change at same time, seemed easier than clamping off all the hoses. 42,000 miles since last change.

Yes, I did replace PCV a couple weeks ago.

A little dish soap on pipe fittings made rubber hoses easy to slide on. Good call.

Got everything back together and car ran fine, did a three mile test run and all good! Thanks to all for your help!

PEH

 

Ah, MAP (Manifold Absolute Pressure) Sensor, around 3 o'clock, just below throttle body?

Conduit plugs are pretty easy: they're pre-bent in the direction they previously plugged in, never far from where they go.

 

Yes! Right below throttle body...

 

Recent video on the EGR, still watching it. It's an in-depth look at the EGR valve and cooler, with some good tips about the gasket orientations*, assembly tips:

I see he has several more videos.

* All four of the gaskets dimple at the centre opening, so there are two ways they could possibly be put on: with the dimple down or up (apart from the gasket between EGR valve and pipe, which has clips as well). The mechanic makes careful note of the orientation. I see the Repair Manual has no indication about gasket orientation, at least the edition I have.

 

As an update- our 2011 has been at the mechanics for a while now. Sure could use the input of this group, please.

The mechanic first installed a new EGR valve and cleaned the intake and cooler pipe. Still ran rough, shaking and loud at idle and speeds up to around 35 mph.
Back to the mechanic for spark plug and boot replacement. Still ran rough.
Stayed at the mechanics, for intake manifold replacement and cleaning. Mechanic says it was quite cartooned up again. Afterward it shook upon starting, then ran smooth, then is rough again.

He said there is a 'sweet spot' speed, but is throwing 219A and Cylinder 4 codes. He doesn't believe it's a cylinder compression problem. It also inconsistently throws an 'imbalance air-fuel ratio' code.
He's perplexed- thinking to look at injector or injector control next? wonders if it's an intermittent sticking valve?

Any suggestions?
Thanks,

 

"Any suggestions?"

Did your mechanic also clean the actual EGR COOLER? That must also be done as part of the process.

 

Dang it, now my OCD is gonna make me check the video against my EGR cleaning crib sheet:

 

Get the codes from the mechanic. The complete ones. A code is five characters. Most will start with a P or a C. The "imbalance air-fuel ratio"—what code was that? What is he reading them with?

Injectors would be a logical place to look. Lots of things can cause rough running besides EGR issues. But no need to get ahead of things; what are the codes?

 

Can you check my sketch (pdf attached also)? I've followed the orientations in that latest video I just posted. I hope:

 

Nice! I will double check it just for fun.

 

The one I definitely recall was the exhaust manifold to EGR cooler gasket. It had a notch in it that was at the 11 o’clock position when looking from the front toward the rear of the car (North America version). I’m wondering if that notch was part of a mechanism to hold it in place during factory assembly (my speculation).

I’m not sure that orientation matters much so long as the interfaces are made to be as even as possible but that’s my 2 cents in the absence of FSM guidance. I did replace my gaskets with new as required in the FSM as they were so cheap which is probably more important.


iPhone ?

 

There's a convex/concave deflection around the central opening around the central openings, on all the gaskets:



Maybe it doesn't matter; not sure. The Repair Manual doesn't say anything.

 

Thanks, I'll ask him.

 

Thanks, I will pass this along to him.

 

Thanks, I will pass this along to him.

 

The mechanic said he will clean the cooler again.
He said it concerns him that the car acts the same with or without the EGR hooked up.

Does that raise concerns for you all, as well?

What would you look at next?

 

I would look up the blessed trouble codes.