OMEGA 2.5 Coolant Leak - IanR
I have a coolant leak at the rear of the engine on my 1999 2.5 V6 Omega although it is only minor and doesn\'t necesitate frequently topping up the reservoir.

The leak runs down the back of the block on the offside, adjacent to the gearbox leaving a very small drip on the garage floor but is only apparent once the engine has cooled down.

My local Vauxhall dealer has had the car in three times now and charged me over £550 to replace the coolant bridge seals at the back of the engine, a thermostat housing and a heater valve. On each occasion the system as been pressure tested. Within a couple of weeks the leak reappears.

Does anyone have any ideas as to what the cause could be? If so any advice would be much appreciated.

OMEGA 2.5 Coolant Leak - lauriew
Ian, Is there a core plug at the back of cyl head?
Can you use a mirror to check.
OMEGA 2.5 Coolant Leak - Dynamic Dave
On my old Cavalier I had a re-occuring leak every couple of weeks or so. I found it was leaking where one of the rubber houses was fixed to a metal pipe. I would tighten the jubilee clip to stop it leaking, only for it to start weeping a couple of weeks later again. The metal pipe was corroded and kept the rust that formed kept crumbling between the rubber and metal surface. It was right around the back of the engine and *very* difficult to get to without removing the inlet manifold. I eventually got around to doing the job by undoing the rubber pipe, cleaning up the metal pipe with some emery paper and then re-assembling. I know the Cavalier engine is different to your Omega engine, but I would check the security of your hoses. You should be able to see where the leak is coming from as the Antifreeze will have stained the engine block. Rinse the old stain off and keep an eye out for any fresh staining.
OMEGA 2.5 Coolant Leak - Bob Chen
IanR,

I had experience of having a leaking hose (parts no. 90 501 210)which comes from coolant bridge to throttle body. Leaking gap was just at the connection to coolant bridge quite similar to what you mention.

I didn't buy an Opel replacement, a 60cm ordinary rubber hose cost me less than 1 pound!

Regards