06 Jetta TDI Stutter

Hi, I have an 06 VW Jetta TDI 1.9L. I have had it for about 2 years now and. I got it at 120,000 miles. It now has 196,000. Ever since I first got it, I have noticed a slight stutter when I am at speeds over 60mph. What happens is I am driving along and I suddenly feel a subtle, but very noticeable jerk. It almost feels as if the car randomly downshifts. When this happens there is only a slight flutter in the RPM (see video https://photos.app.goo.gl/CEugEBjQo6P9L8Kn9).

This problem has slowly been getting worse over the last 2 years. I have no idea what could be causing this. Also, I have noticed the stutter is almost non-existent at low elevations (I live in Colorado, where the stutter is very prominent) I have had no major issues with the car in the 76,000 miles that I have driven it. BUT here are a few things that maybe either the cause or a result of the stutter.
-About 6000miles ago, I received an engine code P2112, which has something to do with the ASV. I took off the ASV and cleaned it up as good as I could. This video was taken after I cleaned it. It still doesn't close all the way (see video https://photos.app.goo.gl/RDqUbb4fAJGB6XTq8). The cleaning did make the code go away, but like I said, It still only closes 75% of the way. The car also smokes a lot now too. Also, If I open the oil cap while the car is on, it blows a lot of air!

Any insight or help would be greatly appreciated!!!

Test the lift pump output, DanG144 has a thread on that.

BobnOH, I will try that, thanks

The ASV code went away after I cleaned it, but the ASV valve still doesn't close all the way. You can see the video for reference.

the tach and stuttering could be caused by the engine speed sensor. or wiring, that sends the rpm to the cluster and ecm.
The ASV isn't a big deal if you have the manual trans, automatic not sure where the limit for safe operation is, however, I believe that the ASV closing 75% should stop a runaway.

EGR, wiring harness.

Check the EGR by pulling it off (kinda tricky on the BRM, three Torx screws in an awkward spot against the firewall*). First make sure it is totally shut, I use a flashlight to shine past the sealing surface. If it is gunked up, you will have to clean it first. Then, with it still plugged in, but hanging loose on the intake, do an Output Test and see that it goes its full range, and closes completely again. You may want to do this several times.

If that all checks out OK, put the valve back in, then do the Basic Settings for EGR, verify that all looks OK.

Then, with the engine running, but making sure the A/C is switched off, so the fans won't come on, carefully wiggle the engine harness, especially around/near the starter. See if you get any hiccups, as well as if any DTCs get triggered, regardless of the MIL on or off.

oilhammer said:

Then, with the engine running, but making sure the A/C is switched off, so the fans won't come on, carefully wiggle the engine harness, especially around/near the starter. See if you get any hiccups, as well as if any DTCs get triggered, regardless of the MIL on or off.

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Do this with all wiring that goes through the engine bay and be thorough.

Neither of us said gentle either, not saying you should try to rip them out, enough you know there really isn't something you're missing.
Sometimes you really have to move the wire to get it to do something it does occasionally.

One other thing is to pull the harness as if you're trying to stretch it, not hard, firmly, This is to get the broken wires to separate and force the condition.