Q7 CATA vs CNRB engine reliability?

Cobra · Jan 8, 2020

Hey everyone,
New member here looking to seriously purchase a 2010-2013 Q7 TDI within the next ~2 weeks to replace my B7 A4 2.0t.

My budget is around $13k(want a Prestige ideally)- which is why I'm looking at these years. I've found out that for 2013(CNRB), apparently the engine had a slight redesign with 2 fewer timing chains, weighs 55lbs less, and just 15 more hp(negligible), and better fuel economy(does anyone know how much better?)

I'd like to do most of the maintenance myself(as I did with my gas 2.0t), and this will be my first diesel vehicle, ever. My concern is reliability. I haven't been able to find much information about CATA vs CNRB reliability wise. In terms of the engine specifics, I found this below at ClubTouareg.

Are there any other differences? Do both come with 8 speed transmissions? If not, what years do come with the 8 speed? Many thanks in advance!

The 3.0 TDI. Audi is only applying the new second-generation 3.0-liter TDI in the models currently on sale in the US: the Q5, Q7, A6, A7 and A8. The engines are paired with 8-speed Tiptronic transmissions.

The first generation 3.0L TDI delivered 225 hp (168 kW) and 406 lb-ft (550 N·m) of torque; the current second-generation engine is 55 lbs (25 kg) lighter (from 458 lbs to 425 lbs), and delivers 240 hp (179 kW) and 428 lb-ft (580 N·m) of torque. (The Gen 2 engine is also a bit shorter than its predecessor.)

The company had set a number of development objectives for Gen2 of the engine, said Axel Macher, head of Thermodynamics/Application V6 TDI at Audi in Neckarsulm, Germany. These included:

Higher power and torque;
Lower fuel consumption;
Meeting ULEV2 emissions;
A start-stop system;
Minimized weight;
Compact design;
Acoustic refinement;
Modular construction;
Optimized driving dynamics; and
Optimized production time.
Audi took 26 lbs (11.8 kg) out of the crankcase, crankshaft, main bearing frame and upper oil pan—the last by switching from aluminum to magnesium. Macher noted that Audi has a new machining process that allows them to make a cylinder bore that will be perfectly round when the engine is operating. “If you have a perfect round bore in engine operation mode, you can reduce the pretension of piston weight, and that reduces friction,” Macher said. Laser smoothing of the bores also reduces friction.

Further contributing to a reduction in friction was going from four chain drive chains to two, as well as a reduction in weight of 8.8 lbs (4 kg).

For the second-generation, Audi further optimized the turbo with integral insulation and by moving away from flange-based mounting to the exhaust manifolds to an integrated component. Reducing thermal mass, it enables the turbo to reach operating temperature more quickly in the heat up phase. Audi also specifically optimized the turbocharger for the North American market to deliver very quick performance off the line. (A design target that appears definitely to have been met, at least subjectively, based on our experience in the TDI vehicles.) In Germany, Macher noted, the turbo is optimized for longer stretches of high-speed autobahn driving.

Tdi1
Changes in the exhaust manifolds and turbo from Gen 1 to Gen 2. Click to enlarge.
Injection pressure in the Gen 2 3.0 TDI is raised to 2000 bar, helping increase the power output and reduce emissions. The piezo injectors also use a multi injection strategy—two small pilot injections, followed by the main injection, followed by a post-injection. This strategy contributes to the quietness of the engine.

You need high EGR rates so you can reduce 70-90 % of the NOxemissions. With the second generation of the diesels, we have a bigger EGR cooler, we have tubes with a bigger diameter, so we have less gas flow resistance. This helps us to make better fuel economy and good emissions.

—Alex Macher

Tdi2
Cooled EGR system. Click to enlarge.

Tdi3
Exhaust gas aftertreatment system, shown in an A7. Click to enlarge

bioburner · Jan 8, 2020

2011 Q7>> is the 8speed transmission 2013>>is the CNRB engine.

Keep in mind 2009-2012 were buyback eligible, so most you see for sale now were bought back, fixed by Audi, then sold at auction. Look at history carefully on these.

There is a thread in the dieselgate forum about 3.O timing chain noise, everyone reporting it has a later 2 chain engine. Jury is still out on whether or not it’s a sign of impending catastrophic failure.

Great vehicles, good luck.

Cobra · Jan 9, 2020

Thanks very much, sir! Looks like perhaps I'll stick with '11-'12 for now.
What should I be looking for specifically on the buybacks? That they were indeed fixed by Audi by looking the vin up on https://audidiesellookup.com, and checking Carfax to see how long they sat at the dealer? Thanks again!

bryanmabbott · Jan 9, 2020

I have a 13 Touareg with the CNRB. A big deciding factor for me between the two engines was the significant mpg increase on the highway and having two timing chains instead of four. I don't have any driving experience with the CATA. Per the sticker, the <12 Q7 gets 24mpg on the freeway; >13 gets 27mpg. The Touareg gets slightly higher rating. Here in the Southwest, most of my driving is pure highway at speeds above 70. If I stick to 70mph, I'll usually average 29mpg. At 85mph it'll go down to 26mpg. I like having the extra 100 mile of range too.

bioburner · Jan 9, 2020

Cobra said:
What should I be looking for specifically on the buybacks? That they were indeed fixed by Audi by looking the vin up on https://audidiesellookup.com, and checking Carfax to see how long they sat at the dealer? Thanks again!

Meaning some were ridden hard and put away wet with differed maint, etc. then sat for long periods before being fixed and resold. I’d be looking at the Carfax for a full documented service history.

casioqv · Jan 9, 2020

Does anyone know how to tell what maintenance was done at the time of the buyback? I just purchased a buyback 2009 Touareg 3.0, and it looks like they did lots of stuff... new brakes, and wipers at least. I'm guessing all the filters and fluids were done too but am not sure, so I will do them again.

casioqv · Jan 9, 2020

I'm new to these also, but the biggest reliability issue seems to be HPFP failure. I see a lot of people worrying about the timing chains, but these have been out over a decade and failures are almost unheard of.... it doesn't seem likely to be an issue IMO.

GolfGTD · Jan 10, 2020

I was on the market for Touareg myself all that was out the window as soon as I test drove a Q7 TDI. The vehicle as a whole to me offers a lot more value at similar prices to the touaregs. I test drove a 2012 at first and while I found that combo completely adequate, it wasnt until I drove my 2014 that I really fell in love with the engine and its output as a whole. The 12 drove just fine , had toruqe but not peaky like I feel on the 14. For a vehicle of it size it jsut got up and moved with serious presence but again not compleetly blown away but its accelaration, that was until I tried the 14 for whatever reason that enigne just has so much more character to me, perhaps the spike in torque curve has some to do with what you feel at the seat of the pants. I would suggest going with a 13 and up if you can. Also down the road if you ever want to tune it, it will be much more tunner friendly with higher gains once you do the delete.

Cobra · Jan 14, 2020

casioqv said:
Does anyone know how to tell what maintenance was done at the time of the buyback? I just purchased a buyback 2009 Touareg 3.0, and it looks like they did lots of stuff... new brakes, and wipers at least. I'm guessing all the filters and fluids were done too but am not sure, so I will do them again.

So I don't think that there's a way to tell what maintenance was done during the emissions fix, unless the dealer/owner has reciepts or if it was documented on the Carfax.

Also, does anyone know what the S line package includes, exactly? Thanks!

Q7 CATA vs CNRB engine reliability?

Cobra

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bioburner

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Cobra

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bryanmabbott

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bioburner

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casioqv

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casioqv

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GolfGTD

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Cobra

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