Have you got the heads back? I'd leave the valves alone if I were you. If the heads have been skimmed there's too much of a risk of scratching them messing around with the valves. Sit the heads on the bench combustion chamber up, put some spark plugs in and fill each combustion chamber with white spirit or diesel. If it pours out of the ports, the valve seats need doing, if it doesn't, leave them alone and bolt it back together.

But doesn't the XK8 engine have 4 small valves per cylinder not two bloody great big ones?

You really do need to get under it and have a good look. I'm still inclined to think it is a seized propshaft UJ (probably on the rear), anything else isn't going to be rotating fast enough to hit resonance at that low a speed, but you aren't going to find that without taking it off to check properly. You could always try driving it with the rear prop removed and see if the vibration goes away. If you do that make sure you put nuts on to hold the parking brake drum on or that will try and make a bid for freedom. Driving it like that permanently will bugger up the viscous coupling in the transfer case but just driving it for a short time to check won't do any harm.

I use one of these https://www.amazon.co.uk/Laser-0287-Valve-Spring-Compressor/dp/B0012M9G6O/ref=sr_1_14?ie=UTF8&qid=1539803138&sr=8-14&keywords=Engine+Valve+Spring+Compressors and that works fine on every engine I've tried it on. That one you've bought does say it is ideal for motorcycle and small bore engines......

RutlandRover wrote:

It quickly settled down and became lighter again though.

Or was that just that you got used to it?

There's only one part number for the bracket for the front harmonic balancer and using that one means the big lump of metal hits the sump on a diesel. I suppose it would be possible to make a bracket that held it in place that didn't foul the sump. I was thinking maybe you had one and it had dropped off which was the cause of the vibration rather than suggesting you fit one.

More than the estimate, it can only keep going up......

Bit like a mate of mine who's a pro musician. He did a backing track for a TV advert and was getting a royalties cheque in the post every month. When he got a cheque for 68p he figured the ad campaign had ended and that would be the end of it. 2 years later he started getting them again and found that the ad had been dubbed into a different language and was being run in some foreign country but using the same music.

At that price for something with the Britpart name on it, I'd be inclined to go for a secondhand one. If you can get one from a lowish mileage car you should be fine. Mines on the original and at 364k miles, it's only needed to be adjusted once in my ownership (and I doubt anyone did any maintenance on it between the police pensioning it off and me getting it from the state of everything else).

Not sure why, it holds the heatshield in place and is actually less likely to seize in like the tiny little bolts on the original set up. Takes a bit of fiddling to get the nut behind the shield in the right place but you can use the original brass studs as a guide for length.

It'll never get that bad, or at least not before you notice the oil level dropping at an alarming rate and the view from your mirrors obscured by a huge cloud of blue smoke. You'll notice you've got a bag of 16 rectangular section O rings in the head set. They are the token attempt at valve stem seals used on the same engine when fitted to a Classic so they aren't that important.

Yes, to remove the valves you'll need a valve spring compressor (much like the one in my garage had we known) but if you think that is the total amount of carbon build up in the however many miles the engine has done since new, just clean the piston crown and put it back together. You may decide to take that head off again in another 100,000 miles or so, so you can do the valve stem seals then. Mine were done for the first time when the engine came out to go to V8 Developments at 287,500 miles.....

Burnt oil. Suspect a slightly leaking valve stem oil seal allowing oil to get into the combustion chamber. Did that cylinder look dirtier than the others? I'd be inclined to just clean it off and leave it unless you intend taking the valves out anyway. You should have got valve stem seals in the head set so you'll have them if you do decide to replace them.

My SE has had the brass stand offs for the heatshields replaced with M8 threaded rod. One nut against the manifold to lock the rod in place and another threaded onto it to act as a stop for the heatshield to sit against. Heatshield holes enlarged so the M8 stud can pass through and another M8 nut with washer on the outside to hold it in place.

Changed mine for a Monroe and again, didn't make the steering feel any heavier.

I ran without the drivers side one for about 2 years with no ill effects. Mainly because once the manifold is bolted to the head you can't actually get them in place, you have to sit them in place before fitting the manifold. Passenger side can probably be fitted with the manifold in place. Mine only have about 4 of the original 150 or so tiny bolts holding them on and they don't rattle so maybe you can un-mangle yours and refit them?

Seems that they didn't fit one on the front axle of the diesel as it would foul on the sump, diesels only got them on the rear. Some very early cars didn't get them at all but there was a TSB about fitting one to the rear axle if a customer complained of vibration and they then became standard fit. That just seems to leave the propshaft UJs. You won't be able to feel any slack with them still attached, you'll need to undo at least one end to check them properly.

Of course the other way is to undo the manifold to downpipe studs (which should come off easily as you changed the exhaust recently) and take the head off with the manifold still attached. With the heatshield off you can get to all the head bolts easily enough..

Yes but you need something short on the socket, a ratchet is usually too fat. I ground the threaded bit of a 17mm headed bolt down to a square so effectively I had a 17mm hex on the back of the socket and could use a ratchet ring spanner on it.

I've never known one to burst, especially when the car is just sitting there, they usually just leak when they are perished.

RHD panhard rod is ANR3666 and is listed by some of the suppliers, not cheap though at just over 100 notes a go. Don't forget that for some reason the Lemforder drag link and track rods don't come with nuts so it might be worth ordering them too.

I'd be looking at a bad connection to the GPS antenna, which, according to RAVE, is under the plastic bit at the lower RH side of the windscreen.

Morat wrote:

Suspension arm pin or bush worn but not excessive movement (Front bushes in NS OS Axle mounts to tie bar) - WTF is that?

I suspect that is the panhard rod bushes which will allow the axle to move from side to side and result in some very weird steering. When you turn the steering instead of the wheel turning it pushes the axle from side to side.

If you've got a rear wheel bearing with slight play, it's well knackered. One of mine was rough as hell but there was no play because the half shaft kept it solid.

I had to replace my drag link a few weeks ago. Slight play in one ball joint was an advisory on my MoT too which I wasn't expecting as I'd fitted a new Lemforder one for the MoT 2 years ago. Admittedly it has done the best part of 40,000 miles between the two tests but even so I'd have expected it to last longer than that. Boots, some sort of vinyl rather than rubber, were split on both ends too.