I was thrilled to buy my 1098 Minor back a couple of months ago. In the last couple of weeks I have picked up on a subtle but unmissable knock; whether present or not beforehand I cannot say for sure, nor can I remember whether it made the same noise before I sold it 3 years ago!
It emerges when the car has warmed up after running for 10 mins, and only around or over 40mph. 4.22 diff and 155 x 14 tyres so I put that at around 2500rpm and up. It is most obvious when accelerating. Knocking the car out of gear and revving to about that produces the same result, so evidently an engine issue. I must say it does sound 'bottom endy' but I have never had a shell bearing go on any car I have owned so I don't necessarily speak from experience.
My first thought was that it was down to timing, as since I rebuilt the distributor in July after a break down I have been fine-tuning things (loss-of-power after a long slog down the A1, suspected dodgy condenser but all needed refreshing anyway). A check today shows that the points open to 15 thou not long before TDC, and close on / immediately before TDC. So I don't think it is too retarded. And having retarded the ignition beyond that in the past few days, the knocking remained, so probably not too advanced either?
Any advice on moving forwards would be much appreciated. I have decided not to use it in the meantime. I haven't checked or adjusted valve timing yet, nor done a compression test - any tips on such welcomed. And then there's the prospect of dropping the sump and observing the bearings. If I do this, what should I be looking for?
Annoyingly, I have just done a full oil & filter change - I suppose I should have dropped the sump then. But as a running project I decided that I hadn't the time. I was pained to discover that the filter housing was missing the necessary pieces to filter the oil sufficiently (if at all) but luckily pilfered the bits (spring, seating plate) from my spare engine and remaining washers from the bench. Coupling this with the fact that the oil was black and low when I bought the car, having covered 9/10k miles in the past 3 years - I shudder to think of the possibilities. The odo shows nearly 80k miles and knowing the car as well as I do, I believe that to be genuine and all done on its current engine (it did have an unleaded conversion but I don't think anything lower was touched). Having said that, she motors along as well as always, and hasn't consumed any oil in the last few hundred miles. The heater still produces heat, so I have avoided suspecting the head gasket - but is that test a misconception?
What would you do? Existing threads on this forum have been greatly helpful so far; I would appreciate further input after I've provided this context on my own Moggy woes. I shan't be parting with her again so won't be too upset if it is the worse case scenario; I am happy to tackle anything myself, even if it is a bottom end rebuild...a good friend has advised me that I may be able to get away with replacing the shell in an offending big end?
Many thanks in advance
Lexi