Morris Minor Owners Club

On my way to a job interview today my car started making an unwanted noise (ended up parking the car on double yellows and running to my interview ). Ended up coming home on a breakdown wagon

The noise is similar to the noise I heard when the crankshaft cracked on the old engine, that time the noise was constant when the engine was running. This time it only occurs when the engine has warmed up and I rev the engine. Sounds more like a tapping than a banging from the bottom end though this time.

I have no luck

Did you get the job ?

How's the oil pressure - any blue smoke ?

The guy started asking hours I'd like to work so I think so

Five minutes before the noise started I was traveling down the by-pass at about 50 and the oil pressure was sitting around 50 as well. No smoke at all.

Compression test - to see if the head gasket has blown.........

That could cause the bottom end to rattle?

Hope you have better luck than my brother. He had the same symptoms in his Spitfire on Friday. Stange thing was, when we started it next morning, after an initial rattle, it ran sweet as a nut, no tapping. When we took the head off though, the no 1 bigend had about 2mm drop! Still can't understand how it ran so quiet immediately before the stripdown!

Thick cold oil!
No - head gasket won't cause bottom end rattle - it makes the whole engine rattle! If you really think it's bottom end - then off with it's sump for a look see. But if it had 50 psi oil.......

The car felt like it still wanted to go when it got going - although when the clutch was in it cut out - it sounded like there was something loose in the engine that rattled the more the car revved.

Same as the Spitfire

If the oil pressure & coolant levels are still OK (and oil & water haven't mixed) could you let the engine warm up then look for the noise. Try simple things first, loose bolts, radiator fan touching something, water pump. Obviously be very careful around a running engine don't get snagged in the fan or pulleys.

Unless you are really sure it is the bottom end I would take off the rocker cover and make sure nothing is loose or broken.

Worth a try?

While I was waiting for the recovery guy - in my best suit I might add - I took the rocker cover off and made sure the tappets were tight and hadn't worked loose as I adjusted them recently. They were fine. Will take a proper look on Friday or Saturday (got uni tomorrow and it will be dark by the time I get home )

Darkness is no excuse - use a flood lamp!

I had a very similar problem a few years ago, very loud rattling on acceleration. Thought it might have been a big end bearing gone, but as BM suggests, turned out to be a blown head gasket and a crack in the head between two of the chambers

MColes wrote:On my way to a job interview today my car started making an unwanted noise (ended up parking the car on double yellows and running to my interview )

Respect!

MColes wrote: This time it only occurs when the engine has warmed up and I rev the engine. Sounds more like a tapping than a banging from the bottom end though this time.

Are you sure it isn't the timing? If my moggie is too far advanced, it makes all sorts of unpleasant noises when I rev it.

John

Head gasket gone between 2 and 3 can sound uncannily like a shot big end.
Replaced one on the MOT that sounded like bottom end damage.
What a relief that was

Indeed - head gasket swop ~ £5 and an hour's work, big ends ~ £80+ and a few days' work!

Matt,
Try the manifold nuts too. If they're not tight its possible for an exhaust pulse to push the manifold just enough and "fire" thro' the gap and produce a noise just like a duff big end. As I found out after pulling the sump, findind all the BEs OK, etc. It clatters in time with the engine speed and, of course, is much worse the wider the throttle opening.

Either way, the best of luck, MikeN.

That's an interesting idea! Never had that one.

the exhaust hasnt dropped in its braket and touching the bulk head????
could be possible. happened to me. causes a vibration