oiled up?

[painter]

Having not started my XK8 for several weeks, but in the knowledge that I had a new battery and everything seemed fine on the last run, I turned the ignition confidently expecting a quick roar then level revs. wrong A stutter and clouds of smoke, sounded as though running on heavy choke. This cleared after a few seconds, but the grey smoke was a real worry. Has anybody experienced this after a lay off of several weeks? My main worry is oil leaking past the rings, but this is a relatively new engine!

[Brakebuster]

might be a sticky TB ( throttle body ) they are known to gum up with black residue, it needs cleaning or it will stick, either not letting the engine start , or give very rough running ,

just a possibility

BB

[painter]

thanks brake buster,
I have seen some threads on throttle bodys, and I seem to remember this does not necessarily require a stealer visit. Are they fairly easy to remove/clean etc.?

[mike020150]

It may sound a little simplistic but did you move the car a short distance on a cold engine (e.g. from the drive into the garage) before leaving it for several weeks? If so, from the symptoms you describe it's quite possible that the engine remained flooded with fuel. Mike.

[painter]

Happened again, after a sleep of 3 days, but this time preceded by a worrying noise which is best described as a tray of bolts being moved over a concrete floor, (no rattles), about 1 second duration. Lots of smoke and stuttered for a few seconds then cleared.
The car has only just come back from Dealer with a 'battery drain' fault, ran down a new battery over 10 days. (traced to door wiring)
The engine has only done about 30k since Jag. replacement, but now even that gives little confidence.
Throttle body was checked whilst at Dealers and reported clean.
Now I am expecting something expensive!!! HELP

[D_Doran]

Whilst being no mechanic, and not knowing your car's age and history, the first mention of rattling noise on start-up makes me immediately worry about chains and tensioners. (Hopefully I am totally wrong)

[mike020150]

If you lack faith (or the funds) to use a main dealer again, have you tried one of the excellent specialists, like Dave Marks? It sounds like you need someone with the right skills to take a look at the car in case the problem is serious. Diagnosing noises via the written word is rather like sticking the tail on the donkey, a game of pure chance! Mike.

[painter]

thanks Doran and Mike,
there is no rattle, best I can describe the noise is as previous post. I did have the engine checked out on two occasions by main dealers, and my local one actually supplied the replacement engine to the previous owner so I know it is a genuine jag. replacement. Also they have confirmed that the tensioners are new generation and good order. (30k from new)
Having spent over £4500.00 in less than a year on 'gremlins', yes I think the costs are mounting even for such a stunning car, but if it is a serious problem Iwould have thought the dealerships most experienced to diagnosing engine problems? maybe not.
Sometimes these problems have been experienced by other owners and nice to know the scale of problem in advance. I have rebuilt engines in my youth, but have never heard anything like this and obviously a worry (on cost and reliability)
Will wait a while to hear if anybody has similar experience, but as I am near Land's End I think it will be a limp back to dealer

[Nik]

Hi Painter ,
Just a thought but the colour of the smoke may be a clue , very generally , blue smoke is oil being burnt , black smoke is fuel and grey/white smoke is brake fluid so............ is it possible that a seal has failed in the brake master cylinder or brake servo and is being sucked into the inlet manifold never heard of it on an XK before but ........

Hopefully I'm being helpful ,

Nik

[painter]

Hi Nik,
the smoke is not dark, but haven't really studied the colour as to grey or blue. I would like to think it could be something like a failed gasket, but the noise seems to come from 'down below' in the engine compartment. The engine starts/runs for a couple of seconds before the noise kicks in, and the noise is only for a second, (but a gut wrenching second). If it had a turbo I would tend to think that the problem lies there. (but it is an XK8).
I have tried to imagine all that is happening at start up and what could produce this, but short of a crankshaft bearing momentarily seizing up nothing comes to mind, although I am not familiar with these 4.0 engines.

[binghama]

hopefully you have got it sorted by now..just my thoughts..if you are using a heavier oil than spec it can delay the oil getting to the hydraulic tappets which would cause a CLATTER and of course the valves would not be opening properly until the oil pressure came upwhich would give erratic running and smoke from poorly burnt fuel

[painter]

Hi binghama,
this seems to be getting close to where I think the problem may lay. I have been told that it is not unusual for the VVT to cause a noise as described on start up after being left for several days. Even more so if the ECU has been damaged by water ingress, (which is a strong possibility here) and is not sending out the correct info. to release a valve required to oil up VVT gear. The noise is still there and I have not had time to pursue a remedy yet, but told by dealer that it is not unusual and nothing to worry about - ("even on medium wear and tear they can do this every day")
However I don't like the noise at all and will get around to the necessary fix, which may be a remapped ECU, followed by an ECG
thanks for the response