Hi i have a 2.5 and when i switch it off and sit in it i can hear it boiling and bubbling also even though the cap is on tight it looks like ater is leaking out the top through pressure, Is that what is causing it to boil or is there something else to look for,

Your help is always apprieciated as I am joining the world of omega's.

Spooky..TODAY I had the same thing happen to me.

Would also be interested in the answer here..

May be worth trying another cap if you can.  Had an issue on my old car where the pressure release valve in the cap was buggered so wouldn't hold pressure causing symptoms like you say you can hear.

Also what temp does the dash sit at while driving it?  Does it fluctuate much or does it stay a constant temp of around 90 to 95??

while driving stays just under 100 but when stationary goes just over 100 .

could it be worth emptying the water and putting a fresh load in?

mine never really gets above 95, and on a gentle cruising run can stay at a steady 83ish

Don9247 wrote on 01. Oct 2007 at 00:14:

while driving stays just under 100 but when stationary goes just over 100 .

That is too hot - it should be just under midpoint when cruising, rising to just over midpoint in traffic (when fans should drag it back down)

might be worth giving it a flush through until the water is clear, adding a new mix of antifree/water and seeing how it goes from there.

Mine sits at 85 on the m/way and round town occasionally creeping up to 95 and then coming back down once the fans have kicked in.

have a search on the forum for flushing, there is a lot of advice on how to do the job properly  :y

As already stated i would recommend a system flush and replace the coolant.
Does your heater still get hot???

worth checking your HBV is not leaking - this can let air in which then can cause odd symptoms.

Also worth checking that the expansion tank has not cracked around the filler cap thread.

Kevin

Kevin Wood wrote on 01. Oct 2007 at 12:21:

Also worth checking that the expansion tank has not cracked around the filler cap thread. Kevin

yep, its a resonably common failure...seena few like this

I would also check that the auxiliary coolant pump is running after shutdown. Top Left of radiator, small electric pump.

Mike Collins wrote on 01. Oct 2007 at 16:23:

I would also check that the auxiliary coolant pump is running after shutdown. Top Left of radiator, small electric pump.

This is a good point. IIRC, if you get it hot enough for the engine fan to run (best turn air con off), then shut down, the pump should run until the fan stops.

However, it is running a little hot during normal operation so I doubt it's just this.

Kevin

all sorted flushed the system replaced cap for ecxpansion chamber now all is running fine gets heaters get hot and blow strong hot hair air con is icy cold no more boiling or losing water out the cap all is gooooood ! fixed exhaust leak all sounds lovely.