Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: GPar on 19 March 2010, 09:52:28

Title: Yet another water leak.....
Post by: GPar on 19 March 2010, 09:52:28
....only this one could be terminal.

I've had a very small amount of water loss for at least a year and a faint smell of hot coolant. About six months ago I replaced the HBV (with new GM one), really as a precaution because there was no evidence that the leak was from that area. Car has not been used for a few weeks and on starting up recently I noticed that there is now a more pronounced leak with a steady drip running down the passenger side rear of the engine. It's falling on the exhaust at some point as steam is being produced. I have stripped the top of the engine down to expose the valley between the 'V' but there is no real evidence of a major leak other than possibly a very small bit of weeping from the coolant bridge. It's not wet or even damp in that area. Can feel no wetness around any of the pipes. The leak appears to be lower down on the rear of the engine but I just cannot see exactly where it's coming from. I am virtually convinced that I have the dreaded leaking head gasket that one or two others have reported previously. If it is that, it will probably mean the end for the car unfortunately as advancing years and associated aches and pains mean I wouldn't be able to tackle that job. As a last check I'd like to do a pressure test. I have a spare expansion tank cap, could somebody explain how I convert that to enable me to 'pump' up the system and what pressure should I go to? Can this be done with a bicycle pump or can I use my electric tyre pump?

Any advice and comments welcome.

Thanks

Geoff 
Title: Re: Yet another water leak.....
Post by: Jimbob on 19 March 2010, 09:58:32
could be HG, could be core plug.

im sure we have a miant guide on pressure testing the cooling system...
Title: Re: Yet another water leak.....
Post by: Jimbob on 19 March 2010, 09:59:09
yup

http://www.omegaowners.com/forum/YaBB.pl?num=1225142864

easy to find in the index (see my sig)
Title: Re: Yet another water leak.....
Post by: GPar on 19 March 2010, 10:10:10
Thanks Jimbob
Title: Re: Yet another water leak.....
Post by: Marks DTM Calib on 19 March 2010, 11:01:08
Headgasket much less likely on 2.5 as the bores are smaller.

Oil cooler plate, stat.....possibly even coolant bridge seals....all possibles for minor coolant loss
Title: Re: Yet another water leak.....
Post by: GPar on 19 March 2010, 14:13:52
As I said, no real sign of a leak around any of those areas Mark but I hope you're right about the head gasket. I'll let you know when I've done a pressure test. Incidentally, where exactly is the core plug that might be the culprit?

Geoff
Title: Re: Yet another water leak.....
Post by: Andy H on 19 March 2010, 20:27:00
Quote
Headgasket much less likely on 2.5 as the bores are smaller.

Oil cooler plate, stat.....possibly even coolant bridge seals....all possibles for minor coolant loss
I don't want to be the bearer of bad news but the symptoms are identical to those I had with my 2.5.

In my case the coil/DIS pack had rusted and split the case (but hadn't caused a missfire).

Don't give up on the car too easily. Send DarthLooKnee a PM and establish how much it might cost to get him to fix it first. :y

Also- I can't see why the bore size would make any difference to the tendency of the back edge of the head gasket to fail & leak coolant.
Title: Re: Yet another water leak.....
Post by: Andy H on 19 March 2010, 20:28:53
Quote
As I said, no real sign of a leak around any of those areas Mark but I hope you're right about the head gasket. I'll let you know when I've done a pressure test. Incidentally, where exactly is the core plug that might be the culprit?

Geoff
Behind the bracket that the coil/DIS pack bolts onto.
Title: Re: Yet another water leak.....
Post by: Darth Loo-knee on 19 March 2010, 20:37:57
Andy it is true that 2.5's head gaskets are far less problematic than the 3.0's....

When the Core Plugs pop out the water will pour out of the engine certain not a small trickle.

If your Dis Pack plate is rusty I would first think the HBV as water runs down not up.

Pressurize your system that will show you your leak where ever it is.

Head Gaskets are a big job but once done and then serviced properly will last years. ;)
Drop me a PM I will then send you my phone number if you prefer to talk instead of type :y
Title: Re: Yet another water leak.....
Post by: Jimbob on 19 March 2010, 20:40:17
I had a weeping core plug for over a year....
Title: Re: Yet another water leak.....
Post by: Darth Loo-knee on 19 March 2010, 20:43:34
Quote
I had a weeping core plug for over a year....


Never said they done weep, what I said was
"When the Core Plugs pop out the water will pour out of the engine certainly not a small trickle."

People all jump to conclusions straight away thinking it is the Head Gasket.... when most of the time, not always it is not.
Title: Re: Yet another water leak.....
Post by: Andy H on 19 March 2010, 20:46:05
Quote
Quote
I had a weeping core plug for over a year....


Never said they done weep, what I said was
"When the Core Plugs pop out the water will pour out of the engine certainly not a small trickle."

People all jump to conclusions straight away thinking it is the Head Gasket.... when most of the time, not always it is not.
That particular core plug can't pop right out because of the (possibly rusty) DIS bracket screwed over the top of it ;)
Title: Re: Yet another water leak.....
Post by: Darth Loo-knee on 19 March 2010, 20:50:33
Quote
Quote
Quote
I had a weeping core plug for over a year....


Never said they done weep, what I said was
"When the Core Plugs pop out the water will pour out of the engine certainly not a small trickle."

People all jump to conclusions straight away thinking it is the Head Gasket.... when most of the time, not always it is not.
That particular core plug can't pop right out because of the (possibly rusty) DIS bracket screwed over the top of it ;)


I must be imagining that I have seen popped out core plugs then...... that as soon as you pour water into the reservoir it poured out  ::)
What I am trying to say but seems to be missunderstood is that I would not be pointing my finger at the Head Gasket just yet..
Title: Re: Yet another water leak.....
Post by: Andy H on 19 March 2010, 20:57:29
Quote
Quote
Quote
Quote
I had a weeping core plug for over a year....


Never said they done weep, what I said was
"When the Core Plugs pop out the water will pour out of the engine certainly not a small trickle."

People all jump to conclusions straight away thinking it is the Head Gasket.... when most of the time, not always it is not.
That particular core plug can't pop right out because of the (possibly rusty) DIS bracket screwed over the top of it ;)


I must be imagining that I have seen popped out core plugs then...... that as soon as you pour water into the reservoir it poured out  ::)
What I am trying to say but seems to be missunderstood is that I would not be pointing my finger at the Head Gasket just yet..
Sorry, not trying to spread misinformation :(
I was thinking that the bracket is in the way. If that core plug moves out enough to touch the bracket then I suppose that the coolant will flood out. :(
Title: Re: Yet another water leak.....
Post by: Darth Loo-knee on 19 March 2010, 21:03:59
No problem Andy just the poor bugger who posted the original question may get confused.
For what its worth I would be starting with pressurizing the system which will find a leak, also you can do this with the inlet manifold off, just need to clamp the two water hoses that go to the throttle body then have a bloody good look.... may even see water squirting :y
Title: Re: Yet another water leak.....
Post by: GPar on 20 March 2010, 01:08:25
Poor bugger understands completely! Just getting bits together to make pressure test cap. If it is the core plug, and that's about the area where the water seems to be coming from, is it replaceable with the engine in situ? The way my luck is going probably not.

Geoff
Title: Re: Yet another water leak.....
Post by: Andy H on 20 March 2010, 08:22:18
It is round the back of the engine so all the usual suspects conspire to make it difficult to get to.

[the usual suspects:
Scuttle
Windscreen wiper motor & arms
Inlet manifold
Cable tray]

The DIS bracket is held on with countersunk Torx/star screws.

I haven't changed that core plug myself. I imagine the worst part is getting the old one out  :-/

HTH
Title: Re: Yet another water leak.....
Post by: GPar on 20 March 2010, 09:02:02
Thanks Andy. All of the first four are already removed. Recently replaced the DIS pack, and still have the scars to prove it, but getting the actual bracket off may be a different matter. Anyone done that core plug? Best do the pressure test I guess before jumping to any conclusions though.

Geoff
Title: Re: Yet another water leak.....
Post by: Andy H on 20 March 2010, 09:21:17
I can highly recommend the pressure test.

The cap I made came off a Carlton & I managed to retain the pressure relief valve. I tend to pressurise the system until the relief valve starts to lift which I think happens at about 12-13 psi.

A big leak is obvious straight away. More insiduous ones give you time to have another mug of tea before the drips are apparent (Sherlock Holmes would have called it a 'two pipe problem').

Good Luck. :y
Title: Re: Yet another water leak.....
Post by: Ianb on 21 March 2010, 17:35:24
Evening All
After a major oil cooler leak, and spending hours flushing the system, seems I have a core plug prob. Water (steady trickle) coming from rear passenger side. Drops down onto exhaust to manifold bracket. Anyone know the procedure to replace core plug?
Certainly not HG as car drives fine, and no oil in sump, no smoke from exhaust.

rgds
Title: Re: Yet another water leak.....
Post by: dbug on 21 March 2010, 18:47:01
Quote
Evening All
After a major oil cooler leak, and spending hours flushing the system, seems I have a core plug prob. Water (steady trickle) coming from rear passenger side. Drops down onto exhaust to manifold bracket. Anyone know the procedure to replace core plug?
Certainly not HG as car drives fine, and no oil in sump, no smoke from exhaust.

rgds

You sure - could be HBV or coolant bridge.
Title: Re: Yet another water leak.....
Post by: Andy B on 21 March 2010, 18:59:23
Quote
..... I imagine the worst part is getting the old one out  :-/

HTH

A screwdriver hammered through the middle & levered out usually does the trick!  :y  :y  :y
Title: Re: Yet another water leak.....
Post by: Andy H on 21 March 2010, 19:33:54
Quote
Quote
..... I imagine the worst part is getting the old one out  :-/

HTH

A screwdriver hammered through the middle & levered out usually does the trick!  :y  :y  :y
I did all the core plugs that way on my Range Rovers V8 a few years back but it was bolted to an engine stand at the time :y

I don't imagine there is a lot of space to swing a hammer behind bank 2 when it is in the car :-/