Well, here's an interesting thing...it's obviously been quite mild lately in amongst all the torrential rain, but nevertheless, there have been a few cold morning starts for me since putting in the lifter treatment around 3 weeks ago. I have to say, as far as I can tell the metallic tapping I was getting has now disappeared. This has happened gradually, starting with a mild improvement but culminating in a cold start this morning of around 4C (which previously would always result in the sound manifesting itself).
I wound the window down and started the car. The obvious diesel sound from a cold start-up of course, but not the metallic clatter. I purposely drove the first mile with the window down and all I could hear was a normal, relatively smooth diesel engine sound.
So for me - so far - a very definite thumbs-up for £9 seemingly well-spent on a bottle of lifter treatment.
I felt so pleased with myself that I've just bought some more snake oil in the form of injector cleaner. This may or may not do anything but for the sake of a small cost, now that the car has done 70K miles I thought why not?
I'll post up any further developments regarding the sound, or indeed, any improvement in fuel consumption which might be attributable to the injector cleaner.
Yes, Wynnes seemed to work for me - the tappet noise reduced enough for me to realise the major rattle was the aux belt area, and almost certainly the one-way pulley on the alternator. I stopped using the car at that point, thinking I'd probably change the alternator completely along with the aux belt, idler, crank pulley and tensioner, as necessary. Anyway I wanted to replace or de-flap the plastic & metal inlet manifold before any swirl flaps fell off, and taking the manifold off would allow me to get the alternator out through the top if necessary.
I now have the inlet manifold out. Seems I was too late
Flaps are missing from the spindles on 2 & 3. F
it. Only very recently gone AWOL from the lack of carbon on the flat side of the spindles where the flaps used to be.
I think flap #2 is trapped in the inlet. I could just make out what looked like a thin metal edge using a torch and mirror, but attempting to fish it out that has now slipped out of view. The stainless steel flap is non-magnetic, unfortunately.
As for #3, no idea where that is. There weren't any faults logged and it was running fine, although I've only done 100mls or so since getting the car and being gentle because of the rattle. I'm hoping it too has stuck in the port.
Looks like cylinder head off next, then. Sigh. There's a puddle under the car and it's 2C with chill factor taken into account
Looking at the manifold, I can see the problem isn't carbon build-up. It's the lousy plastic bearings for the spindles, that wear out. The top bearings of spindles 2,3 and 4 each have about 3mm slop in them, and that movement will repeatedly jam the flaps against the inside of the ports until the spot welds break and the flaps fall off. I can see lines in the carbon where that has happened with 2 & 3, before they detached.
This is just terrible engineering. I had bought a brand-new replacement manifold cheap on eBay, thinking a new manifold plus EGR blanked should reduce the risk. But the design is so appalling and doomed to early failure that I won't use it.