Actuate EGR while cleaning? Got the darn minor earthquake when starting.

There's definitely been instances of talented mechanics screwing up re-assembly on here... So it's worth being concerned about, but maybe not too much. I'm actually getting ready to head down the EGR cleaning rabbit hole soon, so looking forward to what other people have to say?

 

To my mind, the valve is pretty straightforward to disassemble and reassemble (to a point). It's easy to get the stator/cap off and the rotor just spins off, and you can push the pintle in and out; you don't really disassemble anything further than that. Goes back together same way it came apart.

What I hear the most about people struggling with is just getting the two stator screws loose in the first place. Three words: hand impact driver. Or something like the Lisle or Thexton seized-fastener kit, with an air source. Just takes a touch, and they're loose.

 

I managed to clean the valve pretty good without disassemble. Pried gently up on the sealing disc with the flat of a knife blade, ran a popsicle stick around the perimeter, with squirts of brake cleaner. Ran clothes and brushes through the other end with note brake cleaner.

 

Yeah I did that, for next time. Hope I've got the right size. IIRC I got m5x16. The ones I got are socket-head cap screw, with a hex recess.

 

That might be setting a frustrating and unnecessary standard for most people, as it's virtually impossible to get the valve reassembled with the pintle fully closed. You have to start by threading the rotor all the way down on the threads of the pintle, and then you have to hold it there while putting the stator/cap back on, or the spring underneath will spin the rotor back up by a few mm. But unless you want to leave your fingertip in there for good (which itself would interfere with the valve operation, not to mention impair your violin playing), you have to let go at some point before you've snugged the cap all the way down.

As a result, the spring will have pushed the rotor back up by a few mm, and then the cap will push it as you snug the screws down, and at the end the pintle will be a few mm open.

It's really no big deal. You can put your thumbs on the pintle and push it fully closed. You will hear and feel the rotor whirring inside as you do, and this gives you a great chance to confirm that it is moving smoothly and isn't binding in any way—a chance you wouldn't get if you somehow managed to reassemble it fully closed.

And even if you don't close it yourself like that, it's still no big deal. As long as it is properly reassembled so it freely moves without binding, the first thing it'll do when you turn the car on is close, from whatever position it might be in.

The valve doesn't have any position sensor; the ECM positions it by dead reckoning from where it thinks 'closed' is, and to get there, it is always pulsing the valve in the "this way to closed" direction, whenever it doesn't want the valve open.

I didn't clean mine that aggressively. I just concentrated on reducing carbon buildup in the exhaust-exposed areas, and knocked some corrosion off the metal fingers inside the stator/cap where it was impinging on the rotor a little. As for the original grease, it was fine. Some of it migrates off the threads and into corners where it doesn't do any good; I scooped those blobs up and put them back on the threads.

 

If you don't want to strip those screws on the egr cap make sure you use a Japanese Industrial Standard (JIS) screwdriver. Japanese cars and motorcycles don't have "philips" screws they are JIS, that's why people always strip them out.

 

After taking them off, they were replaced with stainless steel cap screws for ease of removal for future cleaning.

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You might be thinking of somebody else ... I don't personally discourage disassembling the valve. The only tricky bit is the possibly stubborn screws, which respond very well to a hand impact driver (the kind you bop with a hammer) or to the kind of air-powered seized fastener removal kit you can get from Lisle or Thexton. Just a touch and they're loose, and the rest is straightforward.

What I was saying about the reassembly is you don't have to worry about getting it perfectly closed as you reassemble (which is a near-impossible challenge).

Just don't sweat it. Reassemble it the easy way, and it will be slightly open. Then push it closed with your thumbs. When you do, you'll be testing that it moves smoothly and isn't binding (you'll hear a little whirr from inside), and getting the chance to test that is a good thing.

Even if you don't push it closed with your thumbs, it will close itself first thing when it's back on the car and you turn the car on.

 

As I did not use aggressive solvents or anything on mine, the original white grease on the threads was still there, and was fine. Some of it inevitably migrates away from the threads into odd corners where it does no good. I scooped up the blobs from there and put them back on the threads.

As for lubricating the in-and-out motion of the pintle, it goes through what appears to be a bronze bearing, and those are sometimes impregnated with lube, which is why I'd be cautious about aggressive solvents. There are some high-temperature graphite lubes I might try there, if I were concerned about that having been washed out.

 

I'm glad I saw this thread...finally I saw a thread mentioning how to screw the egr valve rotor down while putting the cap back on...,
recently while cleaning the egr cooler... I took the cap off the valve and the rotor spun...oops...what should I set it back to I thought...
I figure hopefully I did it right...