Tuning the 1.9 TDI PD engines

Regarded by many as the best Diesel engine from the VAG group the 1.9 offers plenty of tuning potential.

It had a long production run and is still regarded by many enthusiasts as a more reliable engine than the later 2.0 that replaced it.


The 1.9 TDi was used in a wide variety of cars from the VAG group and came in different power levels.

All had BOSCH injectors, and Bosch ECU's which are really sturdy and very protective of the engine.

Common faults: there are some reports of the BLE or BXE engines breaking con rods. The second generation PD engines were bullet proof as most of the kinks had been worked out which is more than we can say for the later 2.0 TDI engines.

The 1.9 TDi is regarded by many as the best VAG group diesel engine.

Early engines suffered from cracked injector looms.

Engine codes

1.9 R4 TDI - pre PD units

engine configuration & engine displacement
inline four-cylinder Turbo charged Direct Injection TDI turbo diesel; compression ratio: 19.5:1

Cylinder head & valvetrain
cast aluminum alloy; two valves per cylinder, 8 valves total, bucket tappets, timing belt-driven SOHC
fuel system & engine management
timing belt-driven Bosch VP37 Verteiler Pumpe electronic distributor injection pump, direct injection
Engine codes
89 bhp @ 4000 rpm; 149 lbf·ft @ 1,900 rpm - 1Z, AHU
89 bhp @ 3750 rpm; 155 lbf·ft @ 1,900 rpm - AGR, AHH, ALE, ALH
109 bhp @ 4150 rpm; 173 lbf·ft @ 1,900 rpm - AFN, AHF, ASV, AVB, AVG

1.9 R4 TDI - PD version

Essentially, this revised engine has the same bottom end but has a revised cylinder head for the PD Pumpe Düse injectors.

hot-wire mass air flow MAF sensor, cast aluminum alloy intake manifold, Garrett, KKK or Borg Warner variable turbine geometry turbocharger VGT,  water-cooled EGR, cast iron exhaust manifold

Fuel system & engine management
Pumpe Düse PD direct injection DI: engine-driven vane-type low-pressure fuel lift pump, four camshaft-actuated via roller rocker arms high-pressure Bosch  27,850 psi Unit Injectors with solenoid valve injection nozzles, Bosch EDC16 or EDC17 ECU

Engine codes

  • 74 bhp @ 4,000 rpm;  155 lbf·ft @ 1,900 rpm - BSU
  • 89 bhp @ 4,000 rpm; 155 lbf·ft @ 1,800−2,500 rpm - BRU, BXF, BXJ,
  • 89 bhp @ 4,000 rpm;  177 lbf·ft @ 1,900 rpm - ANU
  • 99 bhp @ 4,000 rpm;  177 lbf·ft @ 1,800–2,400 rpm - ATD, AXR, BEW, BMT
  • 99 bhp @ 4,000 rpm;  184 lbf·ft @ 1,900 rpm - AVB, AVQ
  • 103 bhp @ 4,000 rpm; 177 lbf·ft @ 1,800 rpm - BSW
  • 103 bhp @ 4,000 rpm; 184 lbf·ft @ 1,900 rpm - BJB, BKC, BLS, BSV, BXE
  • 114 bhp @ 4,000 rpm; 184 lbf·ft @ 1,900 rpm - BPZ
  • ​114 bhp @ 4,000 rpm; 210 lbf·ft @ 1,900 rpm - AJM
  • 114 bhp @ 4,000 rpm; 229 lbf·ft @ 1,900 rpm - ATJ, AUY, BVK
  • 129 bhp @ 4,000 rpm; 210 lbf·ft @ 1,800 rpm  - AWX
  • 129 bhp @ 4,000 rpm; 229 lbf·ft @ 1,900 rpm - ASZ, AVF, BLT
  • 148 bhp @ 4,000 rpm; 236 lbf·ft @ 1,900 rpm - ARL, BTB
  • 158 bhp @ 3,750 rpm; 243 lbf·ft @ 1,900 rpm - BPX, BUK

Remaps offer good power gains for very little outlay. Pre 2000 cars will require a bench flash in most cases but post 2000 cars will generally be remappable via the OBD port.

Approximate power figures after a remap with no other mods.
(Bear in mind that peak power figures are only a small part of the equation, the whole torque band is improved).

  • TDi90 = 116ps
  • ​PD90 = 120ps
  • ​PD100 = 130ps
  • PD105 = 135ps
  • ​TDi110 = 143ps
  • TDi115 = 124ps
  • PD115 = 150ps
  • PD130 = 163ps
  • PD140 = 175ps
  • PD150 = 182ps

​PD engines generally give a better power gain than the original TDi engines. Further gains are possible on the standard block by uprating the turbo units.

Typical stage 1 mods often include:
Remap, Lighter flywheel (stick with dual mass though, SMF's are not great on the 1.9),  Sports exhaust, Panel air filter.

Typical stage 2 mods often include: Ported and polished head, Power/Sport clutch, Fast road cam, fuel pump upgrades, high flow fuel injector.

Typical stage 3 mods often include:
 Engine balancing, Internal engine upgrades (pistons/head/valves), Competition cam, Adding or upgrading forced induction (turbo/supercharger).

The 1.9 TDi injectors on the PD130, PD150 will be good for 240bhp, injectors on the lower powered engines including the popular PD100 PD105 and PD115 units will need uprating at 170bhp. The PD150 injectors are a good option to upgrade with, or you could source some high performance ones.

You will get lots of traction issues around 250bhp, so bear this in mind, while your wheels spin you won't be moving!

On these engines you can choose from the GTB2566VK good for up to 245bhp maxing at 3300rpm. ​GTB2260VK  good for up to 315 bhp maxing at 2800rpm, GTB2056VK  good for up to  255 bhp maxing at 2700rpm and the GTB1756VK  good for up to 235bhp maxing at 2600rpm.

There is also the GT2052V good for 225bhp at 2200rpm which would be our choice on a road car.

Other Turbo upgrade options on these engines exist if you are prepared to change the pipework and manifolds. These include the GTB1749V producing up to  205bhp from just 1900rpm, and GTB1756V which is good for around 225 bhp. Some companies offer hybrid turbos which can push power levels to 240bhp or more with the right additional mods.

NB: Turbos will require conversion to Vacuum actuators and have the VNT system set up.

Choose the turbo where the power band sits in your most used rpm range, the larger power turbos tend to come on boost later.

On a track where you spend most of your time at high rpm this is fine but in day to day driving lots of lag can be frustrating to drive.

110 and 90 VE Engines will need uprated fuel injectors as well, the standard injectors on these engines are not good at higher power figures. The 150 head bolts are strong, in all other engines you may experience head lift on stock bolts at large power gains.

Fit uprated head bolts or get some bolts for the 150 and fit these instead.

When pushing another 50 bhp through these engines it is recommended to get a hard pipe kit, joints and pipes that are old are more likely to split apart when you run higher air pressures through them.

New clutches are usually ok with power gains to the 220bhp. Worn clutches will often be ok but it depends on the treatment and condition of the clutch. Worn clutches seem to slip in about half of the cases where large power gains have been fitted.

Newer CR diesel engines are much much cleaner, and they have better fuel management, and pollution reduction measures but lots of short journeys can lead to clogging up of the DPF (Diesel particulate filter). See our guide on how to clean a DPF for more info.

A larger intercooler will also better resist heat soak and would be a good upgrade on these engines.

Please help us complete this article, if you are aware of any engine codes we have missed, common issues or upgrade options including turbos please let us know, we want to make this as comprehensive as possible.

Please join our friendly international forums if you want to discuss any aspects of 1.9TDi tuning in detail.

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Your Constructive comments on this article

10 Responses to “1.9 TDi tuning”

  1. Dave says:

    Hi, just reading through and think you may have listed incorrect power figures for the choice in turbos you recommend, I was under the impression the gtb 2566 was a hybrid 2260, good for well over 300hp?

    • TorqueCars says:

      On the 2.0 TDi the GTB2566 is good for around 340bhp on the 1.9 engines you will not get this due to the lower cylinder capacity and supporting mechanical components so 240-300 is about the practical maximum. We’d be very interested to know peoples experiences and results with these turbos on this engine.

  2. ROkkanon says:

    First of all thank you for the article, very good information for everybody.

    I couldn’t find any information about GT2042V. Can you please check if index is correct, if yes, please provide some additional information regarding his turbo may be a link.

    • TorqueCars says:

      Sorry this is a typo, it should read GT2052V – Darkside developments were selling these internals in the VNT20.

      • Paul says:

        Just after some advice looking at a 2010 touran it’s got the 1.9 103bhp engine in am I right in thinking this is the pd bullet proof engine many thanks

  3. Jaydee says:

    I’ve just purchased a leon 1.9tdi engine code asv

    I also have an audi a3 engone code bkd and heard about cylinder heads failing on those

    Dorset the leon suffer format the same problem
    Is there a code on the head I should look for as on the audis

  4. Benjamin Masinge says:

    Your article is staight on point.I owned vw jetta 4 1.9 tdi 2003 drove it to 450000 km then sold it..That was a bullet proof car recently I got a low mileage one stil a 1.9 tdi.I think this car is a collectors item and is best to fo minimul to it…replace air intake inclufong egr then fit a 2 inch stainless steel exaust,change all oils including gearbox and you good to go.Power is relative but this car is an engineers show off.

  5. jeff Gresswell says:

    A really good article on VW 1.9TDI tuning. Just one question on a 105bhp how much higher can you go before needing a larger intercooler(assuming there already is one!)

    • TorqueCars says:

      Its not so much about the power gain, but how hot the intercooler gets, a larger intercooler resists heat soak for longer. A FMIC is a good option, the side mounted intercoolers are not that fantastic. If you drive at high RPM all the time then an intercooler upgrade is important, if you only use boost to overtake now and then and most driving is only spirited in short bursts then your money is better spent elsewhere.

  6. john youngblood says:

    interesting – would like to knowabout conversion to a north/south orientation considerations and issues

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