Just want to get a bit of a poll here on who does what when they pressure wash their engine. With an aluminum head on the OM60X series engines, do you wait for the engine to cool down before hitting it at the car wash so as not to induce any cracks in the head prematurely or do you just let 'er rip?

Also, anyone happen to have a Becker 1492 head unit laying around and don't want an arm and a leg for it?

Thanks, for the comments about pressure washing, I'd like to take care of mine soon but I know that having the engine at operating temp helps to loosen things up too.