Yes I'm still alive folks,

I've just been incapacitated by a house that needs rather a lot of renovating in certain areas (Kitchen and Bathroom mainly) so the only spanners I've needed recently were for re-levelling and re-sealing an improperly installed bath!

Bathroom tiling is ongoing but we are getting there...then there is the Kitchen to finish, then the garage roof to repair, then the outside brickwork, yard, and roof to tidy up...you get the idea...
I've also had no car crises to deal with, the old girl has plodded on valiantly despite a waiting list of jobs to be done, but last Sunday I decided it was time to put my foot down and get a couple of jobs done, constant house renovation be damned.
I decided to tackle both the spark plug leads/spark plugs, and replace the infamous V6 split coolant expansion bottle - on the basis that doing both jobs together is a lot easier than separately. I got there in the end, but not without a few "uh oh!" moments along the way...
The first problem I ran into is that the bolts holding the coil pack in are pretty corroded and one of them rounded off and initially I was stumped as to how to get it out...I eventually managed to hammer in a slightly different bit and get it to undo. Phew!
The second problem is I managed to drop one of the main large mounting bolts for the back of the inlet manifold down the back of the engine, and do you think I could find it ?

I spent I don't know how long searching from above and underneath with a torch and just could not find it, so I eventually gave up and proceeded to remove the inlet manifold on the basis that I would have a better view down the back with it out. As it turned out I WAS able to find it much later on before reassembly, but I could only barely see it and only just reach it with my magnet on a stick. Phew #2! (It landed down by the intermediate drive-shaft joint)
Problem number 3 was the condition of the inlet manifold gasket - I've never had any trouble getting these off before but this one was really baked on. I don't think it had any sealant or bonding agent, I think it has just be on there so long that it was baked in place. Some chunks wouldn't come off at all and once again I spent quite a while trying to figure out how the heck to get it off without damaging the surface. I'm not proud to say it but I ended up having to use a small wood chisel to chisel the remaining pieces off, it was that badly stuck on!

Nothing else I had including a window scraper would shift it. I did end up scratching the surface a bit, but thankfully only at the outer edges of the bolt holes where it doesn't matter too much.
Now with the inlet manifold off and the inlets plugged with kitchen roll I thought it would be a good time to tackle the coolant expansion chamber so I proceeded to try to syphon it empty, only to find that it was already almost empty. Whoops! That was after being topped up only a few weeks earlier, so clearly the leak at the split had got much worse in the last couple of months, so it is just as well I decided to replace it now. It also points up the fact that apparently the low coolant level sensor is not working...
Even though I had a small measuring jug and a large rag to catch spillage I managed to spill the remaining coolant from the expansion chamber all over the corner of the engine when disconnecting the bottom pipe...(curse words were heard)

Other than that changing the coolant expansion chamber was an easy job with the manifold out.
Once that was finished I returned to the spark plug lead job and removed the spark cassette at the back to find.... Spark plug well number 4 (closest to the coolant expansion bottle) flooded right up to the top with coolant! Ahhhhhhhhh!

Just as well I was changing the spark plugs as well as this one was now completely under water...
Obviously I couldn't remove the spark plug and let that amount of water go down into the cylinder so I spent a very boring 30 minutes or so soaking up all the water out of the well (including the inside of the tube) with bits of kitchen roll, then finally finishing it off with a hair drier to make sure it was completely dry before removing the spark plug...sigh.
On the up side there is absolutely NO sign of oil leaks from the cam box at all on this engine.

Apart from a bit of dirt the cam boxes look like they just came out of the factory...
I also discovered that not only has someone ham fisted snapped the spark plug lead guide at the back where it goes around the curve - they've also snapped the rear cassette in two as well!!

There was a clean break between plugs 5 and 6 on the left hand side - almost as if they'd grabbed it and tried to yank it off without removing the strip that bolts on the left hand side above it...
The spark plugs fitted were single electrode NGK (BKR6EZ I think) that look like they've been in there a very long time. Not fouled but certainly old and worn at the tips and needing a change - I just went with the safe choice of Bosch FR8KDC.
Reassembly was uneventful apart from the manifold gasket scraping and the search for the missing bolt that finally paid dividends..Everything went back together nicely and although the spark plug guide is still split at the back I managed to steal a bolt from somewhere else to at least bolt the front section of the guide in place (that bolt was missing before) so the lead guide and the plug wires now sit properly and securely.
After several hours work I started her up, only to discover a dead misfire on one cylinder that was so bad the engine was shaking and rocking back and forth. Disaster!

I've had the inlet manifold off and spark plug leads and spark plugs out of the old V6 I don't know how many times and never once had a misfire afterwards so naturally I was quite disappointed and a bit worried.
I let it idle for a couple of minutes while I contemplated how the hell I was going to figure out which cylinder was misfiring, (really difficult to do an ignition drop test on these engines because of the ignition design) and it was still misfiring. I wondered whether the spark plug well being drowned with coolant could have caused it, but I had been very thorough drying it out before removing the spark plug and the spark plug and spark plug leads were both replaced as well.
With nothing else to try really I decided to give it a little welly and held it at 2000 for a couple of minutes and the misfire seemed to mostly go away, and it was now idling smoothly. I took it for a test drive around the block and it seemed nice and smooth and quiet - certainly no dead misfire, but the performance was a bit on the lethargic side.

(A little bit like it was the first time I drove it home from Preston - smooth and quiet but lacking in zip and throttle response)
That evening I decided to take it for a bit of a blast to see if it would settle in. I probably drove for well over half an hour including a good hard blast on the motorway and performance progressively picked up and by the time I got home it was going like a little rocket again.
The next day I started it and watched for any signs of a misfire when cold - none at all, idling smoothly right away, and basically it has been absolutely fine since. All this week it has been driving like a little rocket and has been uniformly responsive and zippy, and now that I've had a week to judge it it's definitely running better than it was on the old spark plug leads and spark plugs.
So what caused the complete misfire for the first few minutes after running, and a somewhat lethargic performance that went away after a bit of driving ? I have no idea...