Over 3500 kg MOT

To make a short story long I took the van in for MOT this morning, when booking I was aware that the ALKO chassis plate under the bonnet states that it has been upgraded to 3850kg but the tax book has no revenue weight listed. I tried on line initially to book it as PHG but vehicle was unknown, I then tried as a car and appointment came up.
When I arrived at the test centre the inspector got excited and sent for the manager who came out and said that the booking could go ahead but the emission smoke test had to be carried out as it was over 3500 kg. The emission tester was placed in the exhaust pipe and the van was revved to full throttle, a black plume of smoke at the beginning of the rev and when the throttle was released.. a fail. Despite half a dozen attempts it continued to fail. 4.2 and the pass rate was 3.0 for the turbo diesel.
He completed the remainder of the test and it also failed on the nearside headlamp, high allignment. I asked him did he think the emissions failure was down to fuel or engine problems and he said it could be either. I asked his opinion on whether I should down plate to 3500kg and therefore not have to do the emission test. We looked up the data from the axle weights when I was on the rollers for the brake test and when added together I was over the 3850kg upgrade. The van wasnt emptied for the test and along with myself and the tester. the water tank was full 160 litres and the van weighed 3940kg. Overloaded
I took the van to a diesel specialist and he suggested a conditioner in the fuel and winding the fuel pump back from "felt spec". I got my mechanic to do this and then drive the dung out of it for an hour and took it back for a retest. The burst of smoke was still happening initially when the throttle was pressed but there was no smoke from then or when the throttle was released. The tester this time was more sympathetic this time and didnt rev the dung out of it and it passed. :splits: :splits: :splits:
Now I need to notify DVLA of the PHG revenue weight and get the cheaper "road tax". I also need to identify why I have such a poor payload. Yes the water tank was full and this would weigh approx 150 kg, also the motor bike rack would add a considerable weight but other than that I need most other things already in the garage, maybe not the spare dometic fridge in the garage. The fuel tank was only quarter full.
The van itself must be inherently heavy.

I found it strange and asked both the first and second examiner, both said they were doing it on all over 3500kg. I must look further into this because I think this is quite sore on a 23 year old engine, that is seldom revved hard in its daily life in a motorhome.
Perhaps because there is no revenue weight listed on the tax book, they had to treat it in the HGV test category, rather than PHG that it should be registered in as a motorhome.

No harm to give it a good spin from time to time Paul, a good run up the motorway at 70mph for 5 mins should do the trick,

Isn't you lucky them mot boys didn't do that to the V8 ..........imagine the look on his face when the blast out of that hit the sensor on the machine

Better to let it go if it's not getting used as it would start to cease up

Mine was emissions tested in sept 15 for the first time.
I was told that all over 3500 were now tested.