Gnarly Rattle, Deep Within The Block. MA12

[porkpie700]

Just covered 220miles with my new MA12 and something has gone horribly wrong somewhere deep down in the block...

Engine starts and idles as usual, but it's when the engine is reved to a particular rev-range (i would estimate it at 2000rpm upwards) it gives off a very loud, dry gnarly grinding rattle from the bottom of the block in the cylinder no.1 area.
Any gear, even with the clutch dipped. It hasn't lost power or economy but it does have a tiny dead-spot on the throttle. My friend followed me home when it started to do it and noticed a small puff of blue from the pipe on gear changes.

Suspecting that it's the big-end bearings or worse i have already cleaned and painted my origional MA10 ready to go back in if needed (austin-morris green of all colours).
Someone suggested that mayby it's not as serious as it sounds and might be the oil pump, water pump or timing belt tentioner. My oil pressure is good, cooling system is doing a fine job, the tentioner i wouldn't expect to produce a rattle that can be felt right through the car like that...

It's worth mentioning that i have checked the rocker bar, cam and valves for any play but they're all tight... very tight. Yet a harsh click/knock is sometimes heard from the cam area when revved suddenly but that has been there long before this new noise.
Close-est sound i can give you is when a washing machine is emptying and then the pump runs dry and you get that rough gnarly growl from it.

Has anyone out there experienced this problem and if so what was it, any help as always is greatly appreciated.

 

[frank]

it may only be one bigend if the oil pressure is still ok, try removing one pluglead at a time to see if the rattle changes note :grinning:

 

[RTLkyuubi]

Could do with a video or sound clip, but im guessing that its a big end.

 

[porkpie700]

Nope it makes no difference im afraid Frank. It starts and tick's over beautifully, quiet as a mouse, only when it reaches about 1800 - 2000rpm the noise happens but dissapears again when it's back to tick-over speed.
I changed the timing belt 4 weeks (220miles) ago but didn't change the tentioner (it was fine) or touch the water pump (cause i know those things are flimsy on the 1.2).
That said i am wondering if the water pump is the problem as my uncle had a growl on his mini 400miles after a rebuild and that turned out to be his water pump, granted that's a mini and this is a micra.
I know these pumps are meant to be an issue on some of these engines but there are no leaks and it seems to be giving out good water pressure (heater is certainly hot), i noticed though when i did the cam belt that the water pulley was rusty, but i just cleaned it up and thought nothing of it... as you do. Has anybody known a water pump to be noisey/growly like this before?

 

[imp124]

the water pump might be it, the original water pump turbine is made from metal which would certainly produce a nice growl under the right circumstances

 

[porkpie700]

the water pump might be it, the original water pump turbine is made from metal which would certainly produce a nice growl under the right circumstances

That's what i've heard from a few other people, the engine itself doesn't seem to be directly affected by the fault, it definately hasn't lost any power and pulls along without making the noise if it's kept at low rpm. It definatly has had the pump changed or at least removed at some point in it's past as it has blue gasket sealer all the way around it.
Is there anyway to tell if it's the pump without having to go through the whole pain of removing it?

By the way; it ain't a nice growl, imagine a spinning chain catching against something...

 

[porkpie700]

Some pictures of the engine, for those of you on FB.

If that don't work here's the link;
http://www.facebook.com/album.php?aid=139293&id=839509871&saved#!/photo.php?pid=3501364&id=839509871

 

[superls]

how do you know the oil pressures fine you got a gauge? whats it reading, im having a bit of trouble with my cg, low oil pressure and deep growling/rumbling at a few krpm. but thats the big end bearings.

 

[porkpie700]

how do you know the oil pressures fine you got a gauge? whats it reading, im having a bit of trouble with my cg, low oil pressure and deep growling/rumbling at a few krpm. but thats the big end bearings.

Either that or you need new tentioners... I've checked it all out and the spray bar is giving out nice strong jets of oil, i ran the engine for a few secs while i had the rocker cover off to check this. There is no problem with the oil coz i'm pretty sure that it would have seized up or certainly at least overheated while driving. I'm going to take timing casing off tomorro and check the tentioner and that the belt isn't slapping around in there.

 

[superls]

its not the tensioners, as ive now swapped and shimmed the big end bearings and its sorted it out. did it at the weekend, what a messy job under the car with the bottom of the engine off, lol.

anyway,

like you say check all the easy stuff first, if you can get on the bottom pully, see if theres any end float on the crank.

 

[porkpie700]

I may have fixed the problem, or at least reduced it. The alternator adjusting bracket was loose on the engine side so i tightened it. Then the car decided to run home on 3cylinders, stall, then run normally... I hate this engine, as soon as i get the MA10 done it's going back in and i am personally going to chop that crappy 1.2 to bits with my grinder, then urinate on it!!! :glare:

 

[imp124]

give it me, lol i would strip it down and get it running sweet

 

[porkpie700]

I could put four different coloured lights in the cylinders and make an old-school disco lamp lol. Drill holes in the centre of the pistons, fit the mechanisms, stck on some numbers and turn them into piston clocks. Use the con-rods as door handles maybe, ah the possabilities...