Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: elite col on 21 July 2010, 19:43:34

Title: coolant leak on 3.0l
Post by: elite col on 21 July 2010, 19:43:34
ive found that every couple of weeks my water level appears to go down slightly ie 500ml top up required

there is no visable leaking

could it just be a pin hole in a hose and loosing it through steam when hot?

any known faults?
Title: Re: coolant leak on 3.0l
Post by: djdaveyp85 on 21 July 2010, 19:47:36
Probably Heater Bypass Valve. Best doing a pressure test on water system and should gush out of your leak.
Title: Re: coolant leak on 3.0l
Post by: elite col on 21 July 2010, 19:49:59
is that an easy replacement?
Title: Re: coolant leak on 3.0l
Post by: Lizzie_Zoom on 21 July 2010, 19:55:59
Quote
is that an easy replacement?


Awkward, but straightforward.  Guaranteed to scratch your hands and arms, even after taking off the wipers and scuttle.  In fact it is probably worth taking off the plenum for real ease of access! ::) ::) ;)

It will cost you around £40 all in without TC for part no. 090566947 :) :)
Title: Re: coolant leak on 3.0l
Post by: Lazydocker on 21 July 2010, 19:57:37
Yes it's quite easy, quite cheap too... But, it's in a location which makes it a PITA to do. There's a good guide in the Maintenance section :y
Title: Re: coolant leak on 3.0l
Post by: Darth Loo-knee on 21 July 2010, 19:57:59
Quote
Quote
is that an easy replacement?


Awkward, but straightforward.  Guaranteed to scratch your hands and arms, even after taking off the wipers and scuttle.  In fact it is probably worth taking off the plenum for real ease of access! ::) ::) ;)


I remove the plenum and inlet manifold, leave the scuttle panel etc on  :y :y
Title: Re: coolant leak on 3.0l
Post by: Marks DTM Calib on 21 July 2010, 19:58:07
Sounds like a slower leak, could by HBV but given the loss rate its less likely.

More likely to be stat to block seal or oil cooler plate to block seal
Title: Re: coolant leak on 3.0l
Post by: Lizzie_Zoom on 21 July 2010, 20:00:35
Quote
Quote
Quote
is that an easy replacement?


Awkward, but straightforward.  Guaranteed to scratch your hands and arms, even after taking off the wipers and scuttle.  In fact it is probably worth taking off the plenum for real ease of access! ::) ::) ;)


I remove the plenum and inlet manifold, leave the scuttle panel etc on  :y :y

Good point Daz, that would save time and effort :y :y  I'll try that when I next have to replace the HBV which must be due again on my 'new' car! ::) ::) :D :D ;)
Title: Re: coolant leak on 3.0l
Post by: Entwood on 21 July 2010, 20:02:14
As you are not losing much .. it might be something easier .. :)

Check the header tank neck, where the cap screws on, not unheard of for these to crack, they will then not hold full pressure and there will be a steady but small loss.

It is also possible for the pressure relief valve in the header tank cap to fail, this has a similar effect.

When my 2.5 was losing a small amount of coolant and no signs of leaks anywhere, it was found this way .... run the engine up to full working temperature, to the point that the high range fan cuts in ... (max temp and therefore max pressure) ... then "paint" the header cap/neck area with a soap solution ... in my case the cap itself started to "bubble" .. showing that it was leaking vapour.

New cap and all was well  :y :y :y

Cheaper and easier than an HBV..  :)
Title: Re: coolant leak on 3.0l
Post by: elite col on 21 July 2010, 20:08:37
some good advice guys,thanks i will look into it