Bad sign or why the CPO/Warranty is needed?

So after driving some Jetta Sportwagens and Passats I finally decided on a Passat (I liked the interior size better, but would have loved the wagon utility). I'll make another purchase once its in my driveway.

During the test drive of the 2014 Passat SEL the check engine light came on. Diesel VIN and CarFax show "the fix" completed on 10/31. Turns out it was the DPF and ad blue tank/pump? Service Department is replacing both items before I buy the car but should I be worried or glad they are being replaced before purchase and not within a few days/weeks? I had totally forgotten the Passat needed DEF, is that an added pain or just a add every oil change?

First off, don't fall for the "It has to be Ad-Blue". Buy DEF where it is least expensive.
At Truck stops it will cost under $ 3.00 gal. But you must have a clean container for DEF only.

I've heard some say they fill right from the pump, NOT in a Passat where the fill is in the trunk. There are some cars where the DEF fill is right next to the Diesel fill opening.

The consensus is to fill at oilchange time. I do mine whenever the mood strikes me.
I use a garbage bag to cover the trunk floor as well as the opening around the filler hole.
I use a 1.89 litre VW bought AD Blue bottle with the bottom cut off for filling.

How many miles on the buy back?

I'd actually hound the dealer as to what they are replacing, usually a DPF and adblue don't need replacement at the same time, and dealers love to wave big words at your face as a sign they know what they are doing and are doing what is in you're best interest to gain confidence, when in fact it's just a simple sensor or something.

2012-2014 have had issues with coolant clogging that'd be my main concern.

Eitherway if you're starting on a fresh DPF and adblue tank/pump you'll prob be good for another 100-150K on those units.

Warranty will cover it to 11 years or 162K, so I wouldn’t worry. My 2011 Touareg went through 2 DEF pumps, 3 DEF tank level sensors, and 2 DEF injectors in 100K miles. My Passat has only had a line freeze and crack the first winter. The 2015 Touareg hasn’t had any DEF issues. I think the 2011 was still in the learning phase.

My recommendation is to keep the tank full as the fluid crystallizes and causes issues. At this point I fill it every 10K with the oil changes.

After the fix, my 2015 Passat only needs a DEF fill up about once a year...or more. About 15,000 miles. (Hmm...it may be 12,000?)

It is a non-event. I get a warning WELL in advance of any stranding. (At some low level event, the vehicle will not start. That's your nanny state making sure you don't pollute. I guess it's best you be stranded than any non-urea exhaust get out?)

I recommend buying this: https://www.idparts.com/adblue-def-filler-hose-0005832204-000012499-p-6239.html

Screw it into the top of your adblue (or other DEF) container. Screw the other end into your DEF tank in the trunk. Lift and listen to the glug. When the tank is full, there's no spill, no mess. Unscrew and store for a year.

A good technique (as mentioned above) is to just fill it when you change the oil. Or, as BroncoAZ states, fill it more often. I don't know how much it crystallizes IN the tank, but it will create urea crystals quite readily outside the tank.

Every 10k works for me.

That filling hose looks like a great idea. I had the dealer fill mine last time and recently found a mess of crystals in the spare tire well where they spilled a bunch.

Bronco...I just removed my spare tire to check for inflation (which was at 10 lbs....) and the previous owner spilled so much it looks like fiberglass down in the tire well. Will hot water help dissolve / clean it up? Still searching and this one popped up first.

I was able to use a piece of hard plastic (old credit card) to scrape off/dislodge the bulk of it, then vacuum up the pieces and finish by wiping off the residue with a wet rag.

former chevy man said:

Bronco...I just removed my spare tire to check for inflation (which was at 10 lbs....) and the previous owner spilled so much it looks like fiberglass down in the tire well. Will hot water help dissolve / clean it up? Still searching and this one popped up first.

Click to expand...

Warm water dissolves the crystals, but I also used a plastic scraper and vacuumed what I could.

I haven’t seen much activity from this site, but currently I’m without VW TDI. I moved across country for a new job and sold both the 2015 Passat and 2015 Touareg. We purchased a 2021 Tacoma for the wife and my employer bought me a 2021 Chevy Silverado 1500 ecodiesel. The Chevy is good In the diesel, it’s a solid tow vehicle and has averaged 26.5 mpg overall, but it’s missing the spirit of a VW.

Thanks for the reply. I just used the hottest water i could stand and it cleaned it up. Still took almost 2 hours to clean tire well, carpet, etc... what a mess.

AverageAndy said:

I was able to use a piece of hard plastic (old credit card) to scrape off/dislodge the bulk of it, then vacuum up the pieces and finish by wiping off the residue with a wet rag.

Click to expand...

Thanks for the reply Andy.