Golf R MOT fail on Lambda emissions

[Fastdruid]

We put our 2015 Golf R in for an MOT the other week and it massively failed on emissions. Lambda reading of ~4 (the pass range is 0.97-1.03). No warning lights, no codes.

Anyway, long and short is that the reason for failure was the Thermostat (or Coolant Regulator as I saw on the online parts - p/n 06L121111M) as well as the water pump (P/N 06L121012K) plus they used a new union (p/n 06L121131) and gasket (06K133073). About £325 worth of parts.

Just putting this out there as didn't find any other mentions that this could be the cause.

Thankfully we'd not that long had it and was covered under both Warranty and "MOT Guarantee" from the dealers (as the bill was eye watering).

[citizen smith]

That a real eye opener, the forums mention water pump/solenoid issues. Should imagine the bill was close to £2.5k, still lucky you bought from a reputable dealer with a warranty.

I am still looking for an R, but it has certainly made me think about who I buy it from.

[Fastdruid]

Not quite that bad but still was a £1000 bill (VW main dealer). Not entirely certain how many hours it works out as they just list a figure rather than hourly rate and multiplier. I think it's about £150/hour though so assuming a rate of £75/hour from an independent I'd expect it would still be a bill of ~£600-£650 or so as the parts themselves were ~£350 (although there was £22.44 of coolant in that!)

Thing is that there was absolutely no warning. Expected it to fly through the test (which otherwise it did). Drove absolutely fine. Nothing gave away there was anything wrong. Of course it could have always been like this from when we bought it (we bought it with 8 months MOT). No reasonable amount of checking would have picked it up.

Certainly made us glad we bought it from a dealer rather than privately though!

Edited by Fastdruid on Friday 11th September 08:56