after taking off the sump from the block removing several dead mice and some very old engine oil i have discovered that my sump is quite badly corroded, it appears to have stood for many years with oil in it and this has been contaminated with water.can anyone tell me what material(s) the sump is made from and how best to clean away the corrosion and if it is holed how best to repair it . The sump is from a Magna and appears to be alloy or similar. thanks
You don't say if you have a steel or aluminium sump. If it is steel hot caustic will clean it and you can remove rust either with Bilt Hammers "Deox" (marvellous stuff !) or with bead blasting. Repairs can be made by normal welding. Caustic is dangerous with rubber gauntlets and face mask compulsary - you may wish to take it to one of the outfits that strips paint off domestic doors - they frequently use caustic. If its aluminium DO NOT USE CAUSTIC - the thing will literally dissolve ! I wouldn't use bed blasting either since the beads can stick in the metal and contaminate oil. I have cleaned my M Type sump with aluminium wheel cleaner which I bought from Halfords but "Cilit Bang" from our local Tesco has brought my gear box case up like new. If the aliminium needs reparing the only way is with TIG welding or perhaps a new one from Andy King at mgsparesandrestorations.com Finally if you have the house to yourself for a day you can put the sump in your domestic diswasher. This is also a good way of cleaning ball bearings - the parts will come out pristine !
Good luck - and the dishwasher tip didn't come from me
If you are a member of the VSCC there is a thread headed 'Lumiweld' which debates the relative merits of repairing an ali sump with JB Weld or Lumiweld, as alternatives to TIG welding. The first is an epoxy which is applied cold. The second is rather like brazing with aluminium ie a lower temperature than welding. An interesting thread. Both products are obtainable from Frosts.
I may be mistaken but I thought the sumps are Elektron (magnesium) castings - maybe it depends on which Triple-M model. Magnesium can be TIG welded using an appropriate filler rod, and you should consider heat treatment afterwards.
I take Talbot's point about bead blasting, but having thought long and hard I did lightly blast my sump using Honite (glass bead) from Guyson. This was followed by ultrasonic cleaning and then vapour cleaning, and all seems well. I also coat the outside of the sump with a magnesium preservative made by Croda, rather like a very thin Waxoyl - but if in fact it is aluminium this is clearly a waste of time!