cracked head ?

Need technical Q/A then you're in the right place

Moderator: martauto

Martinaston
E30 Zone Addict
E30 Zone Addict
Posts: 3749
Joined: Mon Mar 14, 2005 11:00 pm
Location: London

Post Tue Apr 04, 2006 10:30 pm

i've spent all afternoon stripping a 325 head in the assumption that it was cracked or the gasket had gone, but after pulling it all apart the gasket is in great shape and i can't see a thing wrong with the head :?

So i need some help if you guys can list all the places you know the head crack's so i'm sure i'm not missing anything and waist £45 for a pressure test.

Cheers
There is NO nucleus.
Widge
E30 Zone Addict
E30 Zone Addict
Posts: 3661
Joined: Tue Jan 11, 2005 11:00 pm
Location: Leeds

Post Tue Apr 04, 2006 10:33 pm

They can crack between the water jacket and the combustion chamber which is usually spottable by the excess corrosion in the water jacket. Or they can crack in the camshaft bearing journals. That's all I know.
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Tue Apr 04, 2006 11:29 pm

Right at the bottom of the rearmost two cam bearings is the most common place I've found. Looks like a thin grey line that won't rub or polish off.
User avatar
6inline
E30 Zone Newbie
E30 Zone Newbie
Posts: 66
Joined: Thu Sep 29, 2005 11:00 pm
Location: Europe

Post Wed Apr 05, 2006 7:40 am

Mine was cracked exactly under the cam 15 to 20 cms. The factorygasket was in perfect condition. "Waste" the extra 35 quid (price @ my machine shop) 45 sounds a bit excessive winkeye
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Wed Apr 05, 2006 8:59 am

Note for anyone suspecting a cracked head - If you take the rocker cover of with the engine running and the cooling system up to pressure, you can actually see beads of water emerging from the cam bearings if that is where the problem is.