19 replies to this topic

[Austin mini 30]

Checked the relief valve wasn't sticking, changed the oil and filter and the pressure was much better but still not 100%. I am going to pull the engine out and sort it properly this week - I have a separate unrelated gearbox issue that developed over the weekend testing so going to pull it out and sort it everything in one go as I want it to be right.  

 

Will get back to you all on how it goes as Ill be checking the pump, bearings and the oil pickup when I'm in there.

 

Cheers 

[DeadSquare]

I once had a toothed lock washer fail and a bolt come loose from the blanking plate, through the gearbox to the oil pick up pipe, and it sucked air in from the gear box.

 

I didn't find it till I had stripped everything down, and found nothing wrong.  The blanking plate was firmly stuck in place, but the central unsupported pick up pipe probably moved under cornering and it came unstuck inside.

[Austin mini 30]

So I pulled the engine and gearbox out at the weekend and opened up the transfer gear housing and the gearbox and have found out that my 'unrelated gearbox issue' must be very related. During the test drives for the oil pressure I started getting a rattle sound from the transfer case so I was suspecting the idler gear bearing. So I thought to myself I'll take the engine out to sort this and then sort the oil pressure whilst I'm in.  

 

Opened it up and the main bearing on the shaft of the gearbox verge of collapsing (surprised at how little noise it was making before hand because it only started after the oil pressure issue!). Small metal filings from the bearing (Near to the oil pick-up) made its way up through the oil pump and has scored it badly giving me the low oil pressure when warm.

 

Upon inspection of the rest of the components all is well since I have only driven up to 5 miles since all this started - lucky! 

 

When I drained the oil the first time there was very little swarf on the sump plug but the second time there was a lot more which worried me however the issue has now been found. 

 

The oil pressure gauge was correct all along and was definitely worth installing to watch the oil pressure instead of the light it has saved a lot of potential damage

 

Moving forward, another thorough inspection of components will be carried out and replacement parts organised - possibly a gearbox rebuild and a new oil pump for a start.

 

Should I replace the big end bearings whilst I'm in here? They don't look worn. All components will be cleaned accordingly to get rid of any fine bits of swarf if there is any... 

 

Thanks for all your guidance  

[Cooperman]

If swarf has gone through the oil pump you would be wise to check the main and big-end bearings, the thrust bearings and the condition of the crankshaft journals. You may need to have the crankshaft re-ground or at least micro-polished. It is very easy to do whilst the engine is out and will mean you will have a completely refreshed engine.

Change the timing chain as well for the few pounds that will cost.

Also check the cam followers but if not renewing them, put them back in the same positions as they came out.

Remember that the big end caps are specific to the rods on which they are fitted.

Whilst doing this you might also check the bores and consider honing and re-ringing, again just because it is so easy whilst the engine is out.

Also clean up the combustion chambers and re-lap the valves.

 

Then you will really be 'good to go' and it will all last a long time.

[Austin mini 30]

Morning everyone - just a small update 

 

Rebuilt the gearbox after the bearing failure (New bearings, baulk rings etc) and inspected the rest of it after cleaning each part and the casing individually - all good. 

 

The engine had a fair amount of work put into it when It went in - after cleaning, a thorough check of the main and big end bearings, journals, cam followers and bores was carried out and there was no issues with any of it as a lot of this work was carried out not long beforehand. 

 

A real good cleanup of everything was carried out - including the oil pickup and oil ways. New oil pump (Kent one), new oil (Valvoline VR1) and filter, gaskets 

 

Got it all back together last night and went a good run - no leaks, gearbox is super smooth and good oil pressure cold and warm as it should be once again

 

Thanks for your help!