Thread: Repair cracked sump without removal

Originally Posted by 123rover50

Maybe if I heat it with the oxy and burn the oil off inside the crack then the JB might stick. Might be worth a try first then the Sikaflex if it fails.

Maybe risky don't want to set off an explosion in the sump . It's a tricky one.

Maybe a heat gun not oxy?

That might work too.
I have an engine wash gun thing works off air. If I put a hose on the end of that I can get it in the drain hole and wash out the inside. That will get the oil out. Then maybe petrol to get the diesel out then heat gun to evaporate the petrol.

Keith

Originally Posted by 123rover50

That might work too.
I have an engine wash gun thing works off air. If I put a hose on the end of that I can get it in the drain hole and wash out the inside. That will get the oil out. Then maybe petrol to get the diesel out then heat gun to evaporate the petrol.

Keith

What could possibly go wrong?

When I tig old oily aluminium I cook it slowly with the oxy until it stops smoking. I then wire brush it, rinse, lather and repeat until it stops grunging up. At that point I'd flux and 45% silver solder, or let it cool, clean with clear PVC priming fluid (a 50/50 mix of acetone and MEK) then JB weld.

As long as you don't get it too hot, the oil will slowly cook off. Chlorinated brake cleaner would also be a good cleaner. Just don't heat it until you are dead sure it's all gone or it'll turn into phosgene and you'll wind up dead.

drain the oil
clean it
drill the ends of the crack
cut a plate thats nicely oversize
wire brush it.

mig weld the plate on.

fill it with oil.

done (if you got it right)

I would do that Dave if I could get the sump off but I cant without taking the engine out which at this stage of my life I dont want to do. And welding upside down is not my forte.
I cant work out why a right angled crack like that would appear anyway. It looks like a stress fracture but nothing outside could do it. I am wondering if there is something on the inside causing it. I will put my borescope up the bunghole and have a look today.
Keith

If nothing has hit it, I would guess it is ultimately the result of a defect in the steel used to make the sump, probably a slag inclusion or similar.