Need a crash course in EGR valve disassembly

not extremely necessary to take it out, you can clean the valve with it in. clean in and around push down on it etc...

 

When I have cleaned the egr valve in the past, I've simply actuated it, then cleaned the seated position. Didn't disassemble everything.

Looking for something to do in Thanksgiving?

I'm sure the garage queen hasn't topped 100 k km's yet.

But maybe your driving has picked up to warrant another round.

 

Back when I swapped in the newer valve, I got this far before I stopped. I never tried to see if those tabs holding on the bearing could be released. I greased the part of the shaft that goes through the bearing, re-greased the magnet’s thread and called it a day. Having the spring released also helped cleaning up the valve side.


iPad ?

 

That's as far as I got, and my conclusion after careful looking was that the pintle is assembled and swaged or crimped without any provision for later disassembly.

 

Can confirm. Thought I could tug out that bottom bearing and it broke right off. This one was destined for the scrap bin anyway.


iPad ?

 

Interesting how the EGR valve topics just keep coming up!
I too am curious about the actual valve, as it seems to me the real issues is the valve not seating properly, which then leads to further carbon build up on and around the valve, and hence worsening the seating and valve operation.
I wondered if a regular maintenance task might be to check the valve operation and make sure it is returning to the closed position, maybe even rotating it to see if that of itself, improves its seating.
When I removed the plastic cover, the magnet rotated of its own accord. So not sure if it needs to be rotated before re-assembly, and if so which way?
If the objective is to ensure that maximum closure occurs, ie, minimising unnecessary flow through the EGR; then surplus movement of the valve is required in the closed position, ie, it can be closed a little further. So should the magnet be at lowest position, fully clockwise rotation, close to the valve seating or the opposite?

 

Thanks so much for this post. I have one I just replaced and would love to take it apart. Is there a way to test the electric parts to make sure it works? It's packed solid like my whole EGR circuit was. 260000 miles and Idk when it if the EGR or intake was every taken off the car prior

 

I'm still keen to get a better understanding of reassembling the valves step motor, whether one just puts the springs back, in then the magnet, and and then the motor cap and let it determine how it wants to wind the screw and magnet, or if there is more desirable setup of the valve spindle relative to the magnet?
Secondly, I am wondering if one can actually clean the valve facing and its seating in much the same way one would an inlet/exhaust valve, but without the grinding paste. To explain, rather than twist the valve with a sucker as one does with engine valves, twist the valve by holding and rotating the spindle:

• Remove the electrical connector
  
• Remove the motor cap, magnet and springs
• Without the springs the valve should push in/out by hand
• Wrap some protective taping around the spiral/spindle thread
• Taking the precautionary approach attach a hand drill (not electric) to the shaft. (Both the weight and speed of electric might be too great?)
  
• Gently pull the valve to its closed position and rotate the drill, ie, and hence the valve in its seating, and by feel clean the valve and its seating by sheer friction?

Note I haven't done this. But am wondering if
@Mendel Leisk has already tried this approach with a valve assembly that is already removed, ie, on a work bench. Hence proved/disproved the approach. If it works it could mean doing this with the whole valve assembly in situ, thus extending the period before the need to do a more thorough clean?
RSVP

 

Because of the way they keep coming up, there keep being questions that have already been answered in older ones.

The engine can run poorly either because of EGR flowing when it isn't wanted (such as at startup, idle, or full throttle), or inadequate or uneven EGR flow when it is wanted (mostly mid-loads), and both kinds of issue get reported here and of course they're opposite issues with different sets of causes, so it's probably overly simplistic to try to say what's "the real issue". There are some known issues it's worth knowing about, and the kinds of symptoms they cause.

There's a spring in there, so yes, it'll do that.

Rotating it clockwise (viewed from above) is the direction that pulls the valve pintle closed. When it rotates counterclockwise (and the stator/housing is bolted down), that pushes the pintle open. (Of course, when the stator is removed, rotating the rotor counterclockwise just unscrews it off the pintle.)

You shouldn't really have to be too obsessive about how you assemble it, because the control strategy explained in the repair manual is that the ECM is just always sending steps in the clockwise direction at all times when it doesn't want EGR. So even if the rotor hasn't started out at its fully-closed stop position, it'll get there in a matter of seconds.

But somebody did recently report having hard starting after reassembling the valve, which got easier after re-reassembling it, working a little harder to keep the rotor spun down to that point. I don't have a great explanation, but someone did report that.

If you have the valve completely out of the car, then after reassembling it you'll see the pintle a little bit open, and just give it a hard shove closed with your thumb, and you'll hear and feel the rotor spinning inside and now you'll know it's closed. That has the added benefit of confirming for you that nothing is jammed up. But you can't do that if the valve's attached to the cooler.

You don't really want to play with the surplus movement. Yes, when the rotor is lowest, fully clockwise, that's the fully closed position, and there is a positive stop molded into the rotor to make sure it stops exactly there.



One of the issues we know about for this valve is that the rotor can end up with a track mashed all the way through that ski-jump stop, and then it doesn't stop at the fully-closed position, but goes past it. In essence, that gives you the "surplus movement" you're thinking of, but it turns out not to be a good thing.



The reason it's not a good thing is this: the way the ECM finds "closed" is it just sends pulses in that direction all the time, and trusts the rotor will eventually hit that stop, and that's where closed is.

When the ECM wants open, it just counts the step pulses it sends in the other direction.

So if the ski jump is mashed and the rotor went a bunch of steps past closed, then whenever the ECM wants the valve open, it'll be a bunch of steps short of the correct opening.

 

From a couple years ago, more detailed info on how the valve operates and can be tested can be found in this post and this one.