TDI information

Kremerert

New member
Joined
Feb 24, 2025
Location
US
TDI
none
I would like to get some information relative to the TDI diesel power plants. I'm not new to diesels as my wife (Excursion) and I (F350) drive the 7.3L diesel powered trucks. I can work on them myself given they are relatively simple...turbo, injector, etc. upgrades. I also have the Forscan software which allows me to hook up a laptop to the OBII port and do system analysis when need be. Both trucks have intake/exhaust work done along with a programmer which I strive for engine life longevity and fuel mileage. I also have a diesel Kubota tractor to take care of down in south Texas.

I'm currently looking at getting another smaller diesel SUV for our youngest daughter who is 16 and driving a 2008 Ford Edge Limited. I'm trying to put her in a car to prepare her for when she goes off to college and in addition allow me to get familiar with it prior. We've been looking at the Audi Q7, but ruled it out since it's so big for her needs. So we've been looking at the BMW X5 35d and the Audi Q5 TDI...she's leaning towards the Q5 for now. I found a 2014 with the Prestige package in the color combination we want...white on tan. It has a few miles on it compared to others we found at 159k which had the dieselgate emission warranty work done at 57k in 2018, so I'm guessing the warranty has expried. The car has one previous owner from here in the Houston area thought the car is now up in the Dallas area at a smaller dealership. The Carfax shows no accidents with only 2 recent service records at a high end shop in town. The car looks well taken care of, and with the area adjacent I'm guessing the car was even garaged. The mileage doesn't necessarily concern me especially given it was driven an average of 14k a year rather than sitting, which I think a diesel needs. I'm assuming it has not been deleted and/or tuned, but don't know for sure at this time. It doesn't appear these TDI power plants are plentiful in the Q5 from what I've been able to tell.

I have looked over some threads here via the search feature, but want some better input:
Would this mileage concern you TDI guys even if the emission system is still intact?
Is there a software out there to load on the laptop to be able to connect to the car via the OBII port for codes and such?
What are the biggest concerns for engine longevity...fuel pump grenade, emission system clogging, etc.?
How reliable are the electrical system items on this car as it has alot and my philosophy is it's more to break, but we all know how this younger crowd is?
I will look to eventually tune and delete so wondering the cost of this if I DIY it?
The engine looks fairly straight forward to work on...minus all the emission plumbing...

I did consider the gasoline option of the 3.0L too, but is seems like the costs of it are compatible to the TDI. I would think resale would be better on the TDI later down the road too...
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline '14 A6 Technik S-line
I'll give this a shot.... won't go into too much detail, as you're asking a loaded question.... so let's see what your reply will be and I'll add more later.

To check the Dieselgate status on a VW or Audi, use these links

For any VAG product, the go to diagnostic software used is VCDS

You can get an idea of some of its capabilities and workflow by watching the RT youtube channel... they've got quite a few videos on various things.

There's also a fantastic support forum to go with it

The biggest thing to consider is the complexity of the vehicles you're looking at... not just the TDI aspect of it (although, the 3L CR engines are quite complex compared to the "tractor tech" you've mentioned as having experience with in your post.... lots of sensors, lots of emissions control, lots of expensive parts, etc.

Your will find that engine in Touaregs, Q7s, Q5s, A8s, A7s, A6s on this continent.

The most common issues with that engine are emission control related... DPF\EGR\NOx and other expensive sensors.
The most feared failures are fuel system related
(HPFP failure will take out the whole fuel system and you're looking at an $8k repair to replace everything)
Electrical systems can be a nightmare, as they are very complex, and if you're not used to VAG wiring diagrams or electrical troubleshooting, you'll have a very bad day.

The good news is, these aren't exactly new vehicles (or tech), and there's help and support out there if you're willing to learn.

All factory manuals and wiring diagrams are a must if you want to turn your own wrenches.

Don't cheap out on parts or maintenance.... none of which are cheap... but it makes a big difference.

Any of these vehicles, are top notch vehicles when properly kept\maintained\serviced, but they will quickly turn on you and treat you like a Trophy Wife would, at the fist sign of neglect, however small or unintentional.
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline '14 A6 Technik S-line
Here's a few education guides on some of the options listed above
 
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