Bought it for £350 from a mate of mine around early August 2011, KNOWING FULL WELL that he hadn't changed the oil in it for the year or so that he'd been its keeper. I felt lucky, and carried on driving it for a few hundred miles to see what happened. :doh:
Noticed the engine made a slightly worrying shing-shing-shing sound at low revs, which I suspect in hindsight was noise from the cam chain about to wear out completely. I cheerfully put up with that minor sound effect, as well as the front brakes operating quite unevenly suggesting warped discs.
Ran it as my daily commuter, and went to a couple of local camping trips around north Wales. Seemed to be getting about 80 miles per £10, when driven in a saintly manner. Less when hurrying.
On returning from camping in Beddgelert, the engine began to sound like a diesel tractor. Inspection revealed that at least the upper cam chain was flapping around far too much. Found that the top tensioner bolts were loose, causing a hydraulic pressure drop. Tightening this, and performing a far-too-late oil change, made only a wee bit of difference. Clearly, there was far too much wear in the tensioner/s if not the chain/s themselves. £145 later, I had the chain and sprocket and tensioner kit from Rollings in Wrexham (great motor factors).
Well, the Haynes manual says you can do the cam chain with the engine in-car, but not how tricky it is if there's only one of you. Thanks to my ex-army mechanic neighbour, we removed everything down to the timing plate and quickly got our heads around the timing philosophy. He fitted the chain set while I was at work, then we both worked on rebuilding the engine with gusto on my next day off.
Restarting was a painfully disappointing experience. It ran immediately and stabilised, but sounded like a bag of spanners on a spin dryer. It was as if the valves were just clipping the piston crowns, although hand-cranking the engine never met with any resistance or clouting sounds.
Got plenty of timing chain advice from Frank via micra.org.uk (THANKS FRANK (Y)), and made sure that we'd timed it up correctly, which we clearly had. Checked the shim clearances and found a few of them to be just beyond Haynes manual limits, but nothing evil. Cranked the engine for ages without plugs in, looking for oil starvation around the cams, with no obvious conclusion.
So I decided to just cautiously run the beastie anyway, and to my delight and surprise the diesel impression ceased after about 30 miles. :laugh: I can only conclude that there was perhaps some sludge in a gallery somewhere, marginally starving the cams/shims of oil, until the fresh oil dissolved the deposits. Anyone else experienced this?
Next steps: take it to the seaside for a quick holiday, get some fresh front discs, and find someone who likes refurbishing Micra cylinder heads one day. Will also learn how all the emission control system works.
Noticed the engine made a slightly worrying shing-shing-shing sound at low revs, which I suspect in hindsight was noise from the cam chain about to wear out completely. I cheerfully put up with that minor sound effect, as well as the front brakes operating quite unevenly suggesting warped discs.
Ran it as my daily commuter, and went to a couple of local camping trips around north Wales. Seemed to be getting about 80 miles per £10, when driven in a saintly manner. Less when hurrying.
On returning from camping in Beddgelert, the engine began to sound like a diesel tractor. Inspection revealed that at least the upper cam chain was flapping around far too much. Found that the top tensioner bolts were loose, causing a hydraulic pressure drop. Tightening this, and performing a far-too-late oil change, made only a wee bit of difference. Clearly, there was far too much wear in the tensioner/s if not the chain/s themselves. £145 later, I had the chain and sprocket and tensioner kit from Rollings in Wrexham (great motor factors).
Well, the Haynes manual says you can do the cam chain with the engine in-car, but not how tricky it is if there's only one of you. Thanks to my ex-army mechanic neighbour, we removed everything down to the timing plate and quickly got our heads around the timing philosophy. He fitted the chain set while I was at work, then we both worked on rebuilding the engine with gusto on my next day off.
Restarting was a painfully disappointing experience. It ran immediately and stabilised, but sounded like a bag of spanners on a spin dryer. It was as if the valves were just clipping the piston crowns, although hand-cranking the engine never met with any resistance or clouting sounds.
Got plenty of timing chain advice from Frank via micra.org.uk (THANKS FRANK (Y)), and made sure that we'd timed it up correctly, which we clearly had. Checked the shim clearances and found a few of them to be just beyond Haynes manual limits, but nothing evil. Cranked the engine for ages without plugs in, looking for oil starvation around the cams, with no obvious conclusion.
So I decided to just cautiously run the beastie anyway, and to my delight and surprise the diesel impression ceased after about 30 miles. :laugh: I can only conclude that there was perhaps some sludge in a gallery somewhere, marginally starving the cams/shims of oil, until the fresh oil dissolved the deposits. Anyone else experienced this?
Next steps: take it to the seaside for a quick holiday, get some fresh front discs, and find someone who likes refurbishing Micra cylinder heads one day. Will also learn how all the emission control system works.
