Re: New poster - and a bit of help...
Neil Williams wrote:
> Hi all,
> I've been lurking for a bit, but now it's time for my first post
> (though perhaps not in the best of circumstances)...
> About 2 months ago I bought a 1983 Series 3 SWB 2.25 diesel.
> Generally it has been a good runner, except for a bit of what I
> suspect to be timing chain noise which was down on my list to be dealt
> Yesterday I was going down a dual carriageway at about 50mph (with
> overdrive, so not stupidly high revs). Suddenly, I lost power and the
> Landy started kicking out a lot of thick black smoke from the exhaust
> (previously there was very little smoke except for a bit of unburnt
> diesel on a cold start). Lifting off the accelerator more or less got
> rid of the smoke, but to be safe I cut the engine and coasted into a
> lay by.
> Once in the layby I tried restarting the engine, which was successful
> except for that it misfired and smoked badly on the slightest use of
> the accelerator, and it revved itself slightly on startup but not
> after that, probably due to a quantity of unburnt diesel remaining in
> the cylinders. It seemed to idle more or less OK if slightly rough.
> In the end I got home care of the RAC rather than to risk doing any
> more damage.
> So, before I start ripping things to bits tomorrow and ordering parts,
> does anyone have any idea what could be the cause of this? Could the
> timing chain (already noisy) have stretched or jumped and put the
> timing slightly out, or is it more likely to be a head gasket
> failure, burnt/otherwise damaged valve(s) or cracked piston? (I
> didn't open the radiator, and the engine didn't seem unduly hot,
> also there was no loss of engine oil so it can't have been burning any
> quantity of that).
>  I'm aware that it is an interference design, but is one tooth
> enough to cause bent valves etc, given that the engine still runs
> (just about)? I would suspect not, but could of course be wrong...
>  I'm not convinced of the accuracy, or otherwise, of the
> temperature gauge.
It does sound like the timing has skipped a tooth - and I think it can run
without interference one tooth out. It is something that has happened
suddenly, so this makes it a likely answer. The only other likely thing I
can think of is damage to one or more injectors or the pump due to dirty
fuel or water in the fuel. Catastrophic damage to one cylinder is (dropped
valve, broken piston, serious compression leak etc), I suppose, a
possibility, but if this is the case I think you would commenting on
missing while idling.