Golf TDI 90/110bhp engine query

[william200mph]

Greetings all! This is my first post, so please be kind to me! :-)

I rummaged through the forum (and elsewhere on tinternet!) for the answer to this question to no avail, so if I'm duplicating by posting this topic, it's purely accidental - sorry!

I'm currently driving a humble '88 1.05L Polo which, lovely though it is, isn't my kind of car - perhaps better for my sister, shall we say.. I'm looking for more substance and power (as well as economy!) so am considering a MK3 Golf Tdi.

Anywho, just a quick question. I gather the 110bhp Tdi engine (AFN) is available in the Golf hatchback in the UK, though rare. Is this true? Is it distinguished by twin tailpipes, or is that just a feature of the phase 2 mk3?

I have a budget of around £1k but could possibly stretch if it's very special. I was hoping to get the 110bhp model, if available, to avoid the expense/insurance complication of chipping the 90bhp.

I'd really appreciate any comments on this! Cheers.

[tornadored7]

Hi William,

A warm welcome to the site. I have been a MK3 TDI owner for over 10 years. Here are my thoughts, I hope they are useful.

Firstly regarding the AFN engine, I was looking for one myself and couldn't find one. MK3 AFN engines were available in the UK, but from my own experience they are very rare, and will take some time to source. This scarcity may also command a higher price.

The twin tailpipes are also found on the original TDI (1Z =>90 BHP) engine, so can't be used to identify the 110BHP engine. The tailpipes can be used to distinguish between;

• Twin Tailpipe: TDI diesel [1Z (90), AHU (90), ALE (90), AFN (110), AVG(110)]
• Single Tailpipe: (IDI => Indirect Injection: AAZ engine). Not too sure about the AEY (SDI i.e. non turbocharged, direct injection) diesel engine (I suspect single tailpipe).

I have driven various flavours of the Golf Mk3 TDIs aswell as MK4 Golf TDIs. A well cared for 90 BHP engine is actually quite a driveable car, with reasonable performance.


Chipping the ECU may require unsoldering 2 (E)PROMS from the ECU, and replacing. The performance gain is definitely noticeable !, but may affect your fuel economy. This could be a DIY job, depending upon your competence with soldering tools.

As an alternative to chipping, larger injectors/nozzles (i.e. from the AFN engine) could be installed into the 90 BHP engine, which will produce lower gains than ECU chipping, but without having to overly worry about boost pressure increases.

It is also possible to install both larger injectors/nozzles and have the ECU chipped for some dramatic power gains, but this would hazard your engine as well as your driving license.

Despite applying power increases to a 90 BHP TDI, a serious point to consider is that your brakes will still be underrated (rear drums), and your handling a little wobbly.

Ideally if your budget could stretch a little further, an early Golf MK4 GT TDI would provide improved handling, better brakes (including rear discs) and a 110 BHP engine.

With the budget as a priority, I would take the following approach.

1) Ideally, sourcing a 110 BHP Golf MK3, perhaps asking specailist dealers.
2) Buy a 90 BHP Golf MK3, chip the ECU conservatively and inform the insurance company.
3) Relax the budget slightly and buy a 110 BHP Golf MK4 TDI.

Obviously the service history of the car is all important. Particularly, timing belt changes (60,000 miles or 4 years max) and oil changes (10,000 miles max). Also checking the condition of the Turbocharger.

There is a pool of talented members on this site who can best advise on what to look for when buying a used Golf MK3/MK4 TDI.

[william200mph]

Thank you so much! That was such a comprehensive post from clearly a very knowledgeable VW driver; I shall be bookmarking it for future reference.

Sorry for my slow reply.

Thank you again,

Will