any one used 20w50 MA2 ??

[roryjh]

Since there seems to be polarising opinions on using 10w40 MA2 and 20w50, has any one tried 20w50 MA2 spec oil? Or does this question just highlight my ignorance in mechanics? 

[69hcode]

I think it will be too thick and cause excessive slippage.

[jockduck]

I have used 20/50 in my Mini auto for twenty years now, originally I lived in the tropics and autos have a tendency to run hot so I felt for the engines sake it needed the thicker oil. Now I live in a cooler part of Australia I now feel that 20/50 is too thick during winter. I plan to change to a 10/40 at the next oil change. I believe that 10/40 is specified for later autos.
Jock

[richard1]

It is too thick to properly displace on discs unless it is really super hot, and I mean super hot. I put an oil temp sender in my transmission and even on 35ºC days on hard climbs through the mountains I haven't been able to get the oil temp over 74ºC.

It would also not be recommended for an engine in good shape. I rebuilt mine to standard specs, and with the engine totally hot the oil pressure runs around 42 psi using 10W-40.

[pepomat]

May 15, 2017 23:16:34 GMT richard1 said:

It is too thick to properly displace on discs unless it is really super hot, and I mean super hot. I put an oil temp sender in my transmission and even on 35ºC days on hard climbs through the mountains I haven't been able to get the oil temp over 74ºC.

It would also not be recommended for an engine in good shape. I rebuilt mine to standard specs, and with the engine totally hot the oil pressure runs around 42 psi using 10W-40.

[pepomat]

Hola Richard. Yo utilizo Motul 3000 mineral Ma2 es 20/50 vivo en Paraguay por lo que bastante calor.

[richard1]

I suggest you try the 10W-40. It may shift better. My transmission only runs about 75ºC. And if your engine is in goos shape, the 10W-40 gives plenty of oil pressure. Mine runs about 60 psi until it gets hot, then 40 psi

[hennasxi]

When you say 40 psi when hot, is that at idle in Neutral / Park or whilst driving along?  I am still trying to work out what the ideal oil pressures are supposed to be.   Mine running 10w40 MA2 starts up with 70psi on fast idle but once totally warmed up after a drive this is down to 10psi only at 850rpm idle.   Rev it up to 1100rpm its on 20 psi and at 2000rpm+ its wondering around between 30-40psi.   Is this normal or low ?

[notamini]

Just my own thoughts on that, it's low but possibly borderline too low. Mine runs like Richard's and, in neutral, will sit at 40-45 lbs with 850-1000 rpm.
At 45 - 55 mph, it runs around 65-75 lbs. I still need to check the box side as I am experiencing flaring and chudder once hot. I think I need to replace all rubber 'O' rings in the valve box. My car sat more than it ran for about 20 years before I got it in 2004.

Mark

[jockduck]

There are no rubber O rings in the valve block but there are plenty involved with the internal pipe work and clutches.
Jock

[richard1]

You should have at least 15 psi at idle on a good gauge. If it is lower, you may be approaching the worn bearing point, but might have some other issues. Going to 20W-50 will help the bearing issue, but at the expense of some performance and clutch grip.

O-rings won't affect engine oil pressure, and are located on the shaft from the front plate of the transmission and on the tubes in the converter and front clutch if I remember.

[hennasxi]

OK, I think I will give 20W50 a go, using the MA2 spec stuff rather than standard mineral I guess as MA2 seems to be correct for wet clutches.   If that doesn't improve the oil pressure, looks like its engine out time :-(

[hennasxi]

Update folks on this as it may be of interest.  I am now running 20W50 MA2 spec oil after a filter and oil change and have left two oil pressure gauges plumbed in, one on the gearbox test point and one on the engine oil pressure test point.

I have also forced the engine pressure relief valve shut as a test to ensure this is not sticking when hot to eliminate it from the investigation completely as although I have changed the bullet and spring with a new one, I have to say the new one looked more rough than the original, so I was suspicious of this.

Anyhow, tests have concluded that the gearbox pressure is good even when hot, around 90-95psi constant in forward gears and neutral / park.  This suggests the oil pump is good.

The engine pressure now when piping hot drops to around 15Psi on idle in Neutral, lower when left in D, 1, 2, 3 or R when stationary.

I still don't think this is great, but it is up a little on the readings I was getting with 10W40 in as you may expect.

Going along the car is achieving 35-40 Psi when hot, more when cold, so it appears pressure may not be fatally low at this point however its clearly not right.   Whether there is a blockage in the box somewhere on the engine oil feed side or its the engine itself I am not sure and its beyond my DIY skills to work out.  The engine is low mileage, around 25K on the clock and is dead quiet when hot, I'd have thought if the engine were suffering big end issues it would be clanking away and show other signs of distress, but its not.........yet anyhow !

[hennasxi]

So started the car up today to move it and all OK until I selected reverse, only about 40psi there (on gearbox) and it would not go in reverse.  Put it in neutral, still low, eventually pressure built up to 100psi, tried reverse again, but again it fell to 40 psi and wouldn't go in fully.   Found on tickover it would start reversing, but it wasn't fully in gear.   Moved it backwards enough for me to then try 1st gear.  Same issue, 40 Psi only at gearbox.  Put in Neutral and let it build up to 100psi, after 30 seconds, tried 1st again and it went in gear so I could move the car to where I wanted to park it.

Not sure what to make of that set of readings.  Does this suggest the pump is on the way out after all ?

Next trip for this car will be to a gearbox / engine specialist as I can't do any more on my drive with the facility I have.

[hennasxi]

So after a week or so it doesn't look like the 20W50 MA2 experiment has worked.  It may be co-incidence, but oil pressure is now low when trying to select gears when first started up, drops to about 40psi on gearbox when selecting 1 or R which is not enough for the gear to engage fully.   Gets a little better when it warms up and if you leave it in P or N it does eventually build back to 100Psi, which drops again when 1 or R is re-selected.

I will experiment a little more with warming the car up thoroughly and see what happens, but it would appear 10W40 is going back in shortly, but that will put me back to square one and I will be now looking at engine and gearbox out for refurb and engine rebuild as I can't see what other options I have.

[wimfournier]

Can't be the pump -I imagine- because the pressure goes up to 100 psi once in a while.
It's a question of spilling oil at any place (labirinth) and loosing pressure there.
Pressure build up is only possible against a restrain.