head gasket on a 523 25 6s 4 engine

Hi

I am trying to replace the head gasket on a 98 523 with the 25 6s 4 engine. I have got as far as removing the manifolds and fron water system components. The cams are locked up and the flywheel pinned with 1 and 6 on tdc. my question is, why can i not remove the vanos unit?! It is the one that requires an air tool to release it I believe. I retro fitted a vacuum pump that fits on an airline and run approx 8 bar of air pressure through it, it still wont release. I even attached the vacuum and then did 2 rounds of the engine and re pinned it, still it wont come off. It slides back and forth but just wont come off?!

can anyone shed some light on this for me?

thanks in advance, J

Im not the expert on here about the vanos and dual vanos systems. But you will almost certainly need a big breaker bar on it mate and a quality socket. The bolt is loctited and fairly sure it is left hand thread. The Vanos will have to be retimed when you remove it, because if it isnt in the exact same place as when you removed it, the engine will never run properly at all.

slinky.

Thanks for the quick reply.

the unit itself doesnt have a centre bold, there are 6 bolds which are located engine side of the unit, not really wanting to remove them incase it falls apart down the case! bit wary on just leavering it off aswell as it dont look cheap. I have done the other type of vanos that bolts thru the front case and is on a spline, that just came off by rotating it.

The vanos is an expensive unit indeed! Usually they prove to be faulty when they rattle at low revs and start up, power is lost etc etc.... I will draw this thread to the attention of the other guys, which are more knowledgable with the vanos system.

slinky

Hi guys, seems the conversation has dried up, does anyone have any ideas.