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Hey! Hoping someone can help shed a Light on my issue.. So my old turbo went out and i bought a new renovated is38 from a friend and installed it, car drove fine after install for a day or 2 and then from no where the car shakes and limps when getting on boost

Realised i didnt do a waste gate adaption. So i set the voltage to 3.6 and it aborts the adaption for safety reasons. So i install my old accutator which i know worked before, but same issue. I hear the waste gate working for 3 seconds then it aborts for safety reasons

And i have checked the pivot arm moves freely when disconnected

Anyone got a clue where i go from here?..

Quote from: Napalm on 08 January 2026, 14:55

I dont know, i bought the car with the issue, however its top speed is only 121mph, factory its 137mph,
Update: ive had a smoke test done, reault was inconclusive, no smoke leaked out. Really stumped here guys

137mph are you dreaming  :grin and any idiot doing that in an old mk4 deserves a slap

Cheers for that mate, looking for advice on to stop the whistle when the turbo kicks in lol

I had the same experience trying to get a space saver for my Mk8 GTI - this after bursting a tyre on a pothole 60 miles from home and having to rely on VW Assist / AA to get me home.
I got a space saver with Continental tyre plus complete tool kit at my local breakers - or "vehicle recyclers" as they like to be known now. £60 plus VAT for the lot, and they even checked that it would fit over the front calipers!

Quote from: scottm1 on 09 January 2026, 17:35

I can get a new battery from Halfords but wondering will they code it? The guys at VW said you don't need to do this but tbh not sure I trust them!

The following from Halfords website - Halfords Start/Stop batteries in some vehicles require the battery to be registered with the on-board computer system, so we strongly recommend professional fitting.

It needs doing so perhaps call the branch in advance and check.

Thanks mate, will call them. VW wanted £360 for a new one, maybe see how it is over the weekend and try a garage that I normally use.

Just jumping on this, have a MK7.5 PP 5 years old and got a low battery on Sunday and it wouldn't start. Jumped it and it has worked all week but took it to Halfords for a test and they said it's at 48% and needs replaced.

It has been running fine this week and had it in at VW for an MOT today, vehicle health report showed no issues with the battery. Went to start it to leave VW and the battery had died again and needed to get them to jump it!

I can get a new battery from Halfords but wondering will they code it? The guys at VW said you don't need to do this but tbh not sure I trust them!