Solid valve tap after WoF? - What to do?

[Auzeras 28]

Just wondering what you folks make of this, recently I started commuting out to Paraparaumu a month or so ago. Spent a lot of time driving there and back each day (company paid miles, so I defiantly enjoyed it!) and the car was running well minus a slight but noticeable valve tap due to worn cam & eccentrics on cyls 1-3. Not a huge issue, and hardly noticeable in the car when driving. New head was in the roadmap for next year (mmm Ireland Engineering HD Rockers)

Went overseas for two weeks and got back to find the WoF had expired. I took it to a local shop (not my BMW's usual) who have been very good to our family previously with selling me parts at trade prices and generally looking after our jap cars. It was only a WoF I thought, no problem. Pick up the car later that day and it has a really solid valve tap.. not just a tick/click as the eccentric rides over the cam lobes but it sounds as if it's straight metal slapping metal. Car feels a bit weaker too but not sure if that's me "thinking" its sluggish because the engine doesn't sound right. Fuel consumption is about normal.

This doesn't seem right as she was good when she went in and they only did a WoF, so what could possibly go wrong? Does anyone have any theories or suggestions what to do? Somethings clearly screwed but I'm not sure if it's a freak failure or if they did something during the WoF that caused it to end up like that.

I only really have one theory aside from freak failure: I noticed when they bought it out from their lot the A/C was on + the fans were running full. so I'm guessing the bloke doing the WoF ran the car to try cool it down in the scorching sun & it overheated badly. Temp does climb in hot weather when in traffic, I've never been stuck long enough for it to go up at all high. Worst it got was 2/3's up the guage when the water pump belt came off one day.

I'm going to ring the shop tomorrow and ask If it was idled for any extended period of time and mention that it's come back with a really bad tap, on Thursday I have a day off and plan to pull the valve cover and see what's happened.

In my mind, it went into their shop running good and came out running bad but I don't want to jump the gun & have them say it was already damaged and then have to fork out their inspection costs if I throw the ball at them and say "you fix it". Also they're mitsubishi/suzuki mechanics.. not at all familiar with an old tech E32, although one of them used to own an E34)

Any suggestions as to how to approach it? I'll try post a before/after video of the valve tap.

[BM WORLD 1283]

sounds like your viscous fan coupling should have been replaced long ago .

but yes common for the m30 to chew out its cam lobes , normally due to lack of oiling up the front

from loosing banjo bolts on the oil spray rail bar and lots of slow traffic driving

don't drive it too much like that as the head of the valves can break off because of the extra force when closing due to the worn camshaft.