For PD owners shuddering at idle

[andreigbs]

In the interest of making sure my PD has all the air in needs when I request max "GO!" I decided to check my EGR valve, you know, just to see what the general condition of the intake is. I have only 53k miles on her, been using ULSD since about 35k miles, so it shouldn't be so bad, right?

Wrong. Took out EGR valve (3 little 6mm hex bolts) and what do i find? The plunger was all carbony-gooey and stuck, almost completely blocking ANY air from entering the intake. Some of the yucky stuff fell out as I slid the EGR valve out, whatever was left inside I scooped up so as not to get it sucked in. The intake looks like it could use a cleaning, but it's not bad yet. I think at the first TB change.

Anyway, cleaning out the EGR valve with a can of carb cleaner, bristle brush and some fine sandpaper, got it to look as new. Plunger moves smoothly, slid the valve back in the slot, bolted it up, started her up and all I hear is smooth idling. So I get cleaned up and take it for a spin.

The top end is now alive! The car revs up happily to 4k rpms, the boost is steady as a rock at a hair over 15 psi and when i come to a stop, NO MORE SHUDDERING! Couldn't believe it, and also no more slight smoke at WOT, not even at night in the headlights behind me. The cleaning was a MUST, and it did wonders for my PD; i can only imagine i'm not the only one. using ULSD exclusively, I'm curious what the EGR valve will look like at 100K miles when I'll do the TB.

So before you guys go changing your MAFs and your air filters hoping to regain any lost "oomph", take off the EGR valve and see what's up because you may just be horrified. It brought back memories of my first intake cleaning, all i can say is I don't look forward to another, but such is life.

 

[eb2143]

More evidence suggesting the theory PD's are less prone isn't true..

 

[andreigbs]

exactly what i thought, and i was going to add something about the ULSD but decided to drop it.

i WILL say checking and cleaning the EGR valve is much easier on the PD, and enables you to look into your intake manifold, to get an idea how cruddy it is. with just a cleaning, my PD is running much better.

i should've added that tightening my tandem pump bolts (slight oily leak, not fuel) seems to have helped the warm-start be a quicker one.

 

[JB05]

Glad to hear your PD is running better, and thanx for the info.
Is there an O-ring that has to be replaced or is the old one reusable?
JB

 

[andreigbs]

yes, there is an o-ring where the two surfaces meet.
i cleaned with alcohol and reused.

 

[2004Nick]

Shddering at idle!

Any chanace you could post pictures of the EGR valve Re & Re? Maybe I'm a doofus, but I can't even FIND mine! Where the Hell is it? If no pics, could you at least post some do's and don't's for the proceedure? I've got to get over my fear of working on mine!

 

[TDINJ]

Glad to hear it's running better. Not long ago, I tried to remove my EGR Valve on my PD for inspection. I got the bolts off, but could only barely twist the valve, and couldn't remove it. I put the bolts back in for another day.

Any hints on getting it out. Could be a lot of carbon buildup making it stuck I guess.

Any suggestions?
Thanks.

 

[andreigbs]

well guys, i didn't have my camera with me, mainly i didn't think i'd need to even clean the darn thing, let alone make a write-up. goes to show you that hindsight is alwasy 20/20 and i should've done it.

the cleaning is very straightforward. the EGR valve can be seen once you remove the black plastic engine cover; just snap it up and out. you'll see the EGR towards the left (passenger) side of the engine, it is bolted to the intake manifold and the air intake rubber hose leads straight to it, it has an aluminum round head, you can't miss it . it's held on by 3 small hex screws, i think 5mm. once you remove those screws you can twist it easily and slide out at the same time. remember to unlug the electrical connector. TDINJ, it's very possible that yours is very dirty and thereby opposing you but don't give up. you can't damage anything if it is loosened and you can twist it; just pull it straight out towards you while twisting. be sure to catch all the crud that comes/falls out as the EGR valve comes out and scoop up any loose material that you can get your fingers on thru the hole in the intake manifold. you don't want loose chunks of carbon in there!

once it's out of the car, spray liberally with carb cleaner, make sure to stay upwind of the spray or you'll get spotted (ask me how i know!) and use a small wire brush to clean the whole valve, get it nice and shiny before putting it back in.

you can re-use the rubber o-ring, just clean it off with alcohol and take it off the valve body while you're spraying with carb cleaner and cleaning it.

reinstall back in the intake manifold, tighten 3 hex screws, plug in electrical connector, clean your hands of the gunk, start it up and let it idle for a bit while listening for leaks of any kind. don't go ape-nuts on those little hex screws, i think 15 lbs./ft. is tight enough. take it for a drive and see what it feels like, change each gear at a higher rpm than the previous one (progressive shifting, yeah) and then report your findings. gladly upload pics if anyone of you can take some.