Hoping somebody can help me with a problem I've got. Had to strip the inlet manifold off to replace the diesel leak off pipes. Figured since I had it all apart I might as well chance the rocker cover gaskets both upper and lower because there was an oil leak. As I was pulling it apart I found a lot of what I think was mastik or sealant around the joins but didn't think too much of it. After putting the thing back together it blew that lower gasket out which I took to mean I had tightened it down too much. As some of you will know it's a tall gasket that you "squash" into place between the two flat faces of the head and the valve cover. Having then stripped it all down again today and been very careful tightening it down it seems to have pushed the gasket out again and you can SEE the oil leak and hear it.
Seems to me there is excess pressure building up in the rocker cover but I don't know what would cause that? Anybody shed any light on it for me? And does anybody know if there is a torque setting or technique I should have used for tightening down those 3 valve cover retaining bolts?

I have a Citroen Dispatch (same a Scudo) and am currently having a problem with the 'tall' lower gasket. When I removed the lower cover there was no gasket only black sealant. The upper and lower rocker cover gaskets I had ordered form Eurocarparts are correct for my DW8 engine, but I am now thinking the 'tall' lower gasket is not the correct part as there is no groove in the lower cover for the gasket to fit into, (like the upper cover gasket has) it just has a 'lip', and an instant gasket silicone is the right thing to use!?!
If anyone can help it'd be much appreciated

I used instant gasket, a high temperature one that is used to 'replace' rubber or cork gaskets.
I scrapped all the old silicone off with a stanley knife blade, rubbed both surfaces down with emery cloth, degreased it all before applying a bead all the way aound and assembling. I left it to cure overnight before running the van. A week later no problems!
I later found there was no gasket on my 1.9d DW8 engine.