Interesting that the 13+ changed the egr/intake system. Is this typical for that much build up with only 100,000 miles ?
At 175,000kms our 09 only had a light film....a bit less than 1/16”. One thing I have noticed is the egt’s at immediate stopping, engine still running is the highest I have ever seen on any diesel engine. Always well over 400 deg’s & sometimes over 500. And this is the factory get probe sensors after the turbo, so it is much hotter before the turbo, which is the proper place to measure egt’s. I don’t like shutting down my diesel engines until 300 degs pre-turbo. This would take 10 mins idling with the 3.0L TDI. Crazy. So, I started looking at the egr & intake system of the Touareg.
There is a simple throttle valve motor attached to charge air pipe before the intake plenum on a Gen 1. I have pulled the close off disc completely out of throttle motor which motor still turns the shaft but it can’t block off any charge air when egr requests disc to close & at least that part won’t throw a CEL because it thinks it’s still working. My understanding is the throttle motor closes approx 3/4 of the way when egr requests. This allows the egr flow to pick up by slowing down the charge air & egr provides the rest of flow to engine, until egr no longer requests.
On the Dodge Cummins ( most of my experience ), we simply pull the electrical plug off throttle motor for customers that don’t want to do a delete programmer....it stops motor from working & allowing egr flow into intake...it throws a CEL but gains the customer 2 mpg. With delete programmer, a egr/cooler delete & dpf delete the 6.7L Cummins gains 5mpg.
So I also cut a small piece of tin to make a blocking plate & drilled I believe a 3/16" hole in middle & inserted it in egr runner pipe to intake, where it hooks up before the “Y” of the intake plenum. 1st cold morning 11kms down CEL. Drove back home & noticed just under 350 degs for egt’s in park & dropping fast. That’s an approvement on egt's. So I drilled a slightly bigger hole & afternoon same drive ( we have to drive our daughter to catch school bus 11kms one way & also trying to have a constant for testing/experimenting ), no CEL....Getting somewhere !!!
Next morning another CEL. Tells me the colder mornings, the egr requests more than afternoon warmer drive. So for the heck of it, I took the blocking plate with hole completely out of equation....so back to stock/open from egr to intake plenum.....not ideal but needed to prove a point to myself. Afternoon drive, no CEL. Next morning, no CEL. Ok, that’s progress. 2 days later & drives longer than 50kms, no CEL.
So, I drilled a larger hole & re-inserted block off plate again. Next morning, CEL. so, I’m going to enlarge hole size until morning drive no longer throws a CEL.
I’m eventually going to do the ECM egr/dpf/scr delete but not until I find out what is going to happen with the 3.0L Gen 1 dieselgate mess. Here in Canada, VW is dragging their feet & nobody knows what will happen. Until then, I’m going to experiment.
Mark
