I was directly stating that as far as I could tell, and by tell I would suggest what I could feel, having the setup described above made no difference to my 90. It was just noisy. However a de-cat, and read, remove a blocked up box of soot, on my 300tdi Disco did make a improvement I could feel...

You can see from looking, the valves stay put - they sit on the top. If you were doing your valve clearances, adding new caps would add literally minutes to the job. The seals can be seen, but not very clearly as you are looking through the spring. If you had lost a seal you would probably have...

Not really, just get a nut on it. Lousy garage obviously lost it and didn't give a damn - I would pull them up on it. It's frankly unacceptable actually. They thought they would get away with it because it was hidden! The bolts are not in shear (unless they are loose!) they are in tension and...

I reckon this is going to need to be a custom solution. I would probably create a rack section for the back attached to the Ifor. If only for ladders it would be strong enough, then use a standard rack bar at the front. If you needed more weight or felt the Ifor was not strong enough could...

I would put money on it being valve stem caps. You now have the issue or A working out if they are historical and you have 8 caps, or if recent and caused by valve clearances being allowed to get too great or just poor parts. You need to replace these ASAP or damage will ensue. There is an...

Read my words again and report back.

Depends what engine he has, even so, the cat was knackered so not doing a thing anyway. MoT for diesels only really looks at the particulate. Not the type. Cat was for oxides, NOx etc.

I had a temporary exhaust set up while doing some various bits to my 300tdi 90 and at one point I only had a single silencer, that was a droning racket, I hated it. I cannot understand these little dweebs who go about with baseball caps and noisy exhausts, their cars must just be a nightmare on...

My advice, rip out the Ford engine and fit a 300tdi or better, V8 since diesels are evil apparently. Sounds like it is going into limp home mode of sorts, I don't know what remap you have, a clever well written one will put the engine into sort of standard tune or less if something isn't right...

You really don't need one, I will second, third, forth, where ever we are now the extension bar and socket method. I actually usually just use an extension bar in the centre and rattle it round in a conical/turning motion until I can see the plate is dead centred - there is actually some play on...

Brand new head?

You are welcome. What sort of mileage is on your engine?

I have re-read your original description of the problem just to help with this remote diagnoses and you made the following points. No issue starting and no smoke at start. Smoke only appears when the engine has warmed up. Smoke appears when you come off the throttle - puffing smoke at this...

Argh... How many times, I told you your ECU was never damaged. You had a bad connection somewhere. As you alluded to yourself, removing and replacing the relay may have cleaned up a dirty terminal.

I will suggest you are wrong yes. In early stages of seal deterioration it is the vacuum of the over run that pulls the oil down the valve stem - yet the seal will offer enough sealing properties to stop oil leakage under non-vacuum conditions.

OK, as said before, jump the relay socket now - basically manually energise the main relay circuit - your ECU will then turn on and you will probably be able to start it. You know which terminals were the coil so I assume you know which terminal is the NO (Normally Open) one, i.e. the one that...

Could be your valve stem seals. Contrary to what oil "should" look like, in this situation the oil can create a whiteish-light grey smoke which can be a bit James Bond smoke-screen stuff.

This is my suspicions as posted above, may not even be the relay but a connection to the coil side is poor and not energising it properly which creates the buzzing noise. I have suggested he looks into how to jump the relay if he doesn't already know how to. The OP needs to be getting a...

You have gone into catastrophe mode, looking for the worst case scenario rather than try and look and the simple things first. The advice given to you above was to leave your ECU alone, you could check the plug externally to see if it may have got oil into from the plugs. Have you looked into...

If a relay is buzzing then it has probably failed or is not getting enough current to energise the coil and keep it supplied with enough current to keep the relay "on". If there is oil in the loom a bad connection could cause a reduced feed to the relay which could have the impact you describe...