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Questions on rebuilding / servicing Polo 6n2 1.4 16v AHW Engine

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Hey guys!


Winter is coming and I don't really plan to need my Polo that much :smile: Thus I'm thinking to invest some time in tinkering with it.


I will soon start a build thread for it, as I initially got it just for a backup car, but now I want to "play" with it :spiteful:. Before that thou, I wanted to ask some questions, about things that I'm not fully clear on :smile:


I do have some power issues with the car. The clutch cable and the clutch itself were garbage when I got the car, and I fixed them, but the shop didn't do a good job with the clutch cable and I'll need to replace it again - the clutch pedal is very heavy, noisy, sticks often and doesn't release smoothly. Still when I compare the car to my brother's Polo (same engine but AUA), there is very noticeable difference in how the car accelerates and how much easier and quicker it revs - it did also have clutch and cable changed at about the same time. It is good to mention that the AUA Polo hasn't seen proper maintenance in about 3-4 years, while in the past 2 years it was running with a faulty head - losing a lot of oil and coolant regularly. Still after a simple head gasket change, clutch and cable it runs times better than the AHW Polo that seemingly doesn't have anything wrong with it... Both Polos have their Cats removed, where for the AHW I have a whole new exhaust, except the manifold.


So, either way I do plan to service the engine of the AHW Polo. And I do have the bold idea of trying to do it myself, mostly as a challenge :smile:


What I want to do:


1. Service the head:

- new set of inlet and exhaust valves

- new valve seals

- polish on the head and the valve beds - outsource :D 

- new gasket

2. Block

- probably just cleaning the cylinders and changing the rings

3. Timing belt

- belt, pulleys, water pump, etc.


Most of the things above are fairly well documented, and I shouldn't find it very hard to do, but I do plan on upgrading the engine in the future at two-three stages, and wanted to know if I should plan ahead, if I'm opening the head


Stage 1 - GTI upgrade


I already have inlet and exhaust manifolds + throttle body from a GTI. I do plan of adding them after servicing the engine. And as far as I know I will need to remap the ECU for the new throttle body


Question 1: Should I even bother with trying to remap the ECU myself, when the change is only the throttle body. An ECU tool is fairly cheap and I think it should be a nice entry level job


At a later stage I might go for the supercharging fun, but wanted to ask about the engine mods that I see being done around it - fast road camshafts, decompression plates, bigger valves, etc.


Question 2: Should these things be done to the engine only when adding the supercharger, or they can be done earlier?

- are these the cams I should be looking for?

- can somebody quote me which bigger valves are being used in such a set up

- would a CLK W208 supercharger do the trick?


Question 3: If I decide not to go for airflow mods, should I just add better cam shafts to the GTI mod and call it a day? Do the new cam shaft (either from a 101hp 1.4 16v or a fast road one) require a remap?


Note: I was thinking about an engine swap, but I decided to play with this engine. I do have a bigger engine car and I am not really looking to make this Polo be something crazy.

Edited by kainy
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  • kainy


  • Duffy


  • dvderlm


How many miles?

Done a compression test?


I don't think AHF and AHW cams are the same. I mended an AHW and could not find upgrade cams. 

Give catcams a call.


It's 16v already so there's not much space for bigger inlets, and bigger exhaust valves won't make enough difference.

Conventionally ~85% of inlet area is fine.


Yes you will need to remap to get best of improved airflow 75hp to 100bhp is 30% more.


If supercharging definitely remap and change ignition curve and fit knock sensor and MAP not MAF.

Suspect the merc will overwhelm it unless bigger injectors.



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After researching a bit more, I'll probably stick to the GTI upgrade coupled with probably new cams and better clutch. That should be enough to make it a bit more drive-able. Catcams' web site says they offer several types of camshafts for AUA and APE engines, but that should apply for the AHW, too I guess. I also saw that changing the camshaft will require ECU remapping also. All this with a good service of the engine should cut it.


After that, at some point, if the crazy gets me, I'll just swap in a 1.8T golf engine in, and call it a day :spiteful: Otherwise I'll put most of my energy in making it pretty :D


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  • 1 month later...

I'm in the middle of mucking about with one of these as well. 


I've gone with a GTI ARC bottom end (a straight swap with the exception of the water pump and crank position sensors -use the GTi pump (it's slightly differently shaped at the rear but otherwise identical) and either the GTI sensor or swap the rear crank oil seal housing over, it's the that dictates the sensor profile) 


Use GTI head bolts as the AHW ones are too long, head gasket is the same profile, bore etc are the same, just a slightly longer throw crank. 


The standard head is poorly manufactured and around the valve seats is full of lumps, bumps and restrictions, its easy to improve with some grinding stones and flap wheels. 


The GTI inlet manifold goes straight on with a couple of tweaks and I'm intending to use 




Which is Polo GTi body except with a cable. 


That'll give you 100 BHP I'd have thought. 

Edited by Duffy
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Thank you! I've recently realized that my throttle body was the cable one, and the GTI I got was the wired one :smile: 


Currently I'm still contemplating if doing a 1.8T (150hp or 180hp) is the better way to go with this, more so when my mother managed to, probably, kill her engine (same 75hp 1.4) and might be easier for me to just give her mine and do the swap :D

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Well, I'm looking to get a complete car for a donor, so I won't have any issues with parts, and shops here tend to do such swaps for around 300-400 euro. The 150hp version can be found easily for around 500 euro, which coupled with saving from a new engine for my mother's car and selling what is left from the donor car, makes it pretty affordable :smile: Sadly the 180hp version (20v) is harder to come by and way more expensive... but I think the normal one should suffice.

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