can this be done?

I need to weld a small crack in the block of my 3.6. Right now I have puddy cement and it is working ok. The Real way to fix it I think is to weld it but can you do this without a complete breakdown? The motor is strong and only has 73K on it.

help

[DustinTarditi]

I'm not a welder, but I wouldn't want to weld any part of my engine with it in place... too many things to get slag on, catch fire, etc.

You're best (optimal) bet is to drop & open the engine and have the crack looked at inside and out... The crack could be asymetrical, meaning that there is a larger broken area on the inside of the block.

If the case half is FUBAR you'll want to replace the block, but there's no way of telling until it's out or in the rearview mirror.

I don't want to sound alarmist, but you need to get a pro to evaluate it regardless.

[HardDrive]

As above. A catastrophic failure of the case at speed would almost certainly lead to complete replacement, and it could be quite dangerous as well.

As a side note, I think it is unbelievably cool that you have a Unimog

[raceman]

leave it as is but keep a close eye on it.lf it isn`t leaking why mess with it?

[Wayne 962]

The procedure for correctly welding aluminum is not straightforward. The shops that I take my heads to pre-heat the aluminum in an oven until it's quite hot. Before they do this, the drill out the crack to give them a good surface to weld on. It all seems complicated to me, but they do it all day long on VW heads. They also recently welded a crack in a BMW 325is head that I was working on.

It's not like tack-welding - you can't do it correctly without removing and tearing down the engine.

-Wayne