Site hosted by Build your free website today!

Tuning up a T4 2400 diesel engine.




Standard 1991 VW T4 2400 Diesels aspirated engine AAB type

The engine of a Standard 2400 D Aspirated engine of a 1991 VW T4 Transporter without turbo (as it was before…)

The old 1991 Volkswagen Transporter 2400 Diesels has a really reliable engine; alas it has the standard limits of all the old mechanically aspirated engines: the highway maximum speed is approximately 120 km/h (78 M/h), moreover, in mountains where the roads are normally steep, it can force the driver to drive too often just in second gear. In general this old engines have a limited pick-up, especially on uphill roads and off road.

Standard 1991 VW T4 2400 Diesels aspirated engine AAB type

Details of the standard 2400 D aspirated engine of a 1991 VW T4 Transporter

To limit these problems on my VW aspirated Transporter 2400 AAB engine I installed a turbocharger.

Turbo number

OEM reference number of the turbocharger of a VW Transporter TDI 2500 of 1996

The best and economical option to do this tuning is to install the manifold intake, the exhaust manifold and the turbocharger of a VW Transporter TDI 2500, ACV engine, 5 cylinders, year 1996. The 1996 T4 Tdi has a similar engine block. The Tdi spares can be found second hand or rotation at a reasonable price. Rotation or new Tdi spares can be found searching in ebay, the keywords are: (T4 Tdi) "krümmer" (collector); "turbolader" (turbo); "Abgaskrümmer" (exhaust manifold); "Dichtungen" (gaskets); "Ansaugkrümmer" (manifold intake) all for the VW T4 TDI 1996.

I also found a spares shop in Germany:

"KINDT ENGINEEN" Schwertfegerstr. 29 - D - 23556 Lübeck - Deutschland Tel: 0049 451 8130680 - Fax: 0049 451 8130681 - website: Andreas Haase, its direct email is:

I wrote a list with the OEM reference numbers from the Volkwagen Etka catalogue of all the spares needed for the elaboration.

They are all "VW Transporter TDI engine ACV - 1996" parts and they are all perfectly adaptable to the 1991 T4 2400 aspirated AAB engine.

manifolds and Turbo

The 2 manifolds with turbo of a VW Transporter TDI 2500 of 1996

2500 TDI Manifold-Intake  Manifold-Intake

Manifold intake a VW Transporter TDI 2500 of 1996


Manifold intake of the VW Transporter TDI 2500 of 1996, details

Manifold-Intake: the VW Etka catalogue NUMBER

OEM Serial number of the TDI 2500 Manifold intake


List of the spares I installed:

Manifold intake: 074 123 713 

Exhaust manifold: 074 253 033 G (VW Etka catalogue only: 074 253 033 C ?) 

Turbocharger: 074 145 701 

Gaskets of the Manifold intake: 074 129 717 

Gaskets of the Exhaust manifold: 028 129 589 B (are 5 pieces) 

& also the gasket: 028 129 748

Exhaust manifold including of turbocharger (rotation) cost: 262 Euro (including shipment) Manifold intake (used): 135 Euro (including shipment from Germany) All Gaskets for both manifold intakes: about 20 Euro

You also need to installs:

Turbo aspiration-pipe (18 Euro) 

A 'motorquality' silicon pipe for the oil (36 Euro) 

A silicon pipe for the oil recovery (22 Euro) 

A pressure oil pipe for the turbo (aeronautic type) (33 Euro) 

Two connectors (7 Euro)

Moreover you need to make the flanges for the turbo & you must close the EGR with a stopper.

The TOTAL cost has been 983 Euro (including the cost of labour).

Exhaust manifold with turbo

Exhaust manifold and turbocharger of the TDI 2500

Exhaust manifold with turbo

Exhaust manifold and turbocharger of the Transporter TDI 2500 - 1996, details

Exhaust manifold and turbocharger of the Transporter TDI 2500 - 1996, details


Please remember that the 2400 Aspired are old engines and therefore you does not have to "pump it" too much exaggerating with the pressure of the turbo!: 0.45 bar is ok.

The pressure of a turbo can be expressed in Bar or PSI (Pounds For Square Inch): 1 Bar is equivalent to 14.7 PSI therefore 0,45 Bar is 6,5 PSI (or 0,4 Atm). A standard big turbocharger on a new engine can work with a pressure of 1,2 Bars but such high values of pressure are not safe with our old engines ! The important is to install the turbocharger reducing the pressure (we regulated it to approximately 0.45 bar) and to leave the diesel pump, EGR and injectors, as they already are, installing merely the manifold & turbo parts of a TDI. Just give some more diesel to the injectors, that is all.

final result 

The final result: Turbo & manifolds of a 2500 TDI install on the engine of my 2400 D


Is good to know that the head engine gasket of the Aspirated T4 2400 D was already a "turbo-type" gasket. Moreover the T4 2400 D the oil filter had already the nozzle for the oil of the turbo.

On my T4 California 2500 D Aspirated we have installed the turbo with a pressure of just 0.45 Bar.

All the spares (manifolds & turbo) of a 1996 TDI 2500 fitted perfectly on my 2400 D.


Turbo and collectors of a 2500 TDI installed on my 2400 D: side view

The result has been quite good. Clearly I did not get a considerable increase of speed, mainly because we left the turbo pressure low and we did not change any diesel pump settings ecc. Besides the pick-up is now good! The T4 is a reasonably better in overtaking other vehicles, even in uphill roads, the acceleration time is shorter and in steep slopes I do not have to reduce gear too often like I usually did before.

Remember that the installation is on your own risk. I do not take responsibilities of any kind: tuning up an old engine is fun, but always uncertain.

I hope that this article will be useful. Good luck!

Cheers, Max

final aspect of the work

The final result…