Anti-Shudder Valve

This has been an intermittent problem for some time; lately it's been consistantly shuddering when I turn the engine off.

I have filmed the valve operating; when cold (or at least, not hot), the valve immediately closes when the ignition is turned off, 2-3 seconds later, it reopens.

I then drove around for 2-3 minutes, stopped, setup the camera, turned the engine off and it shuddered. Replayed it on the camera; the valve closes right as the engine stops and then reopens.

So, the valve is working, but not as soon as it should with a warm or hot engine.

The electrical connection was very clean.

I have had the EGR mod for a long time, so it shouldn't be gunked up.

Any thoughts or ideas?

If it is gunked up, how difficult is it to remove and clean the valve. Has anybody done it? Any tips or cautions to look out for?

Another question, will this shuddering cause damage over time?

Patrick

Possible vacuum leak?

Or binding of the valve due to heat expansion?

Take the big black hose off the end of the intake and take a look inside to see if it's clogged. How many miles were on it before the adaptation?

Use the search function and you'll find lots of info about the EGR/anti-shudder valve assembly and how to clean it and the intake. The tips: be very careful removing any vacuum hoses. The plastic nipples they connect to are easy to break.

No, not likely to damage anything. Older ones didn't have the valve at all.

Thanks for the reply.

I got the EGR mod done at about 16,000 miles; I now have about 26100 miles on the odo.

Also, for the last 7000 miles, I've had a Tuning Box (Kitpower) installed.

Originally posted by Chameleon:
Thanks for the reply.

I got the EGR mod done at about 16,000 miles; I now have about 26100 miles on the odo.

Also, for the last 7000 miles, I've had a Tuning Box (Kitpower) installed.

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<font size="2" face="Verdana, Helvetica, sans-serif">You must have the most miles of anyone with this mod. We are all dying to know the condition of your intake????

Not exactly. I adjusted my EGR about 30K miles ago. It wasn't clogged before, and it still isn't.

Well, here's the latest:

Drove to NAPA (10 miles) to get the hose clamp removal tool. No shudder when I turned off the engine.

Got home, again, no shudder.

So, using my new tool (always exciting), I relocated the clamps to remove the black tube that leads into the EGR.

Took some pictures:

Black tube to EGR inlet:


EGR inlet pic1:


EGR inlet pic2:


The gunk in the black tube was oily in nature. There were some solids (carbon?) in the EGR as well as the oily residue.

To me it didn't seem to enough stuff in there to cause the delay in the anti-shudder valve closing.

What do you all think?

Anyway, I cleaned out the EGR side, reassembled everything and then took the car for a drive to heat up the engine. No shudder when I turned it off.

On another subject, it's interesting to note how much 'cleaner' (relatively) the EGR is on the downstream side of the valve. I guess when the engine shuts down, there's a final belch of soot that gets blocked by the valve's closing.

I've driven 41K miles since doing the EGR mod (did it at 700 miles on the car), and took off my egr for inspection. There was minor buildup, but it was all easily wipeable with a paper towel to expose clean metal. The intake had a slight layer of oily wet coating, but maybe 3-5% clogged at most, just a tiny thin layer. I was tempted to take it off and clean it anyway, but didn't have all the tools necessary.

Question, how does one remove the anti shudder valve from the egr assembly? I had the egr off and wanted to soak/clean it and couldn't get it away from the anti shudder apparatus...there were two torx screws, and part of it came loose, but couldn't get it all the way off...

Question: What do you use to wipe out the EGR (as pictured)? Paper towel and what sort of solvent? Also - is there danger in pushing some slug down towards the other (non open) end and into the engine - which I have read that is a no-no.

thanks.

Originally posted by DEZLBOY:
Question: What do you use to wipe out the EGR (as pictured)? Paper towel and what sort of solvent? Also - is there danger in pushing some slug down towards the other (non open) end and into the engine - which I have read that is a no-no.

thanks.

Click to expand...

<font size="2" face="Verdana, Helvetica, sans-serif">No solvent was used since the EGR was still attached to the intake manifold. I used a paper towel as much as I could; to get to the tight spots, I wore a rubber glove and used my fingers. It seemed to work well.

Anyway, took the Jetta for a long drive (2+ hour drive) today, and it shuddered when I shut it off.

It's starting to look more like a thermal expansion issue causing the delayed valve closing rather than interference due to soot/carbon/crud build-up.

Again, any thoughts/remedies on this?

Can it be fixed or do I need to buy a new valve?

Patrick

Before replacing the valve, I would remove it for a very thorough cleaning. I did this on my 1999.5 at 70,000 miles and it worked fine after that cleaning. It is a little annoying to remove but not to bad; you do need to remove the EGR intake line right below the EGR valve to get at the third bolt. With the EGR off the car you can solvent it to death and get it very clean and then I bet it will work.

Oh, I planned on taking off the manifold on my 1999.5 to clean it when the weather warmed up but my car married a gaurdrail and left me. Now my 2002 has the EGR mod and it works rather nicely.

What solvent did you use to clean it?