Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: MG on 15 September 2020, 10:41:07

Title: Coolant pouring out from rear of engine
Post by: MG on 15 September 2020, 10:41:07
Hi

I have a 1999 V6 Omega Estate which has developed a coolant leak with the engine running and fully warmed up.

As far as I can see the coolant is pouring out like an open tap from the rear of the engine dropping on the floor from the bell housing area.

Can't see any split hoses.

Any ideas?

Any help or advice fully appreciated.

MG
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 15 September 2020, 10:46:44
Probably the HBV.

Change the temperature settings on the climate panel to the opposite* and see if the leak stops.

Presumably it's set to LO or just above, so whack it upto HI and report back  :y
Title: Re: Coolant pouring out from rear of engine
Post by: Migv6 le Frog Fan on 15 September 2020, 11:26:13
Yep, almost certainly HBV (heater bypass valve).  :y
Title: Re: Coolant pouring out from rear of engine
Post by: Enceladus on 15 September 2020, 12:39:38
It might also be the pigtail hose that connects the inlet spigot of the HBV to the spigot at the centre rear of the engine. GM part #90466222. Splits under the clip at the engine spigot end due to old age and heat and nicely showers the bell housing and maybe the coil pack. Very hard to see.

The HBV is more usual but if yours is all right it's probably the hose.
Title: Re: Coolant pouring out from rear of engine
Post by: Alnico Blue on 15 September 2020, 13:02:24
Removing wipers and scuttle will enable you to get a much better look.   ;)

Wipers/scuttle removal process is covered in the Maintenance Guide - external trim  - wipers/scuttle removal .
Title: Re: Coolant pouring out from rear of engine
Post by: Nick W on 15 September 2020, 13:27:50
Removing wipers and scuttle will enable you to get a much better look.  ;)

Wipers/scuttle removal process is covered in the Maintenance Guide - external trim  - wipers/scuttle removal .


£2 inspection mirror and a torch which should be in any toolbox :y
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 15 September 2020, 13:54:13
Hi thanks everyone!

The leak started after the air conditioning was turned on and set to LO. So that concurs with the Doctor's diagnosis!! On closer inspection the top of the HBV where there is a small oblong opening near the mushroom top of the device, looks a little wet as if coolant may have leaked out. Is this how they fail (normally)?

I have already started dismantling the car - the plenum and the inlet manifolds are off and I have fully inspected all of the heater hoses at the rear. I have identified the HBV and have ordered a replacement from autodoc (which I hope is an OK firm to use).

I can't therefore try Doctor Gollum's test as the car is a bit in pieces at the moment - guess I was a little enthusiastic to try and find a split hose or similar ::)

I have also removed the elbow at the rear of the valley area to try and get a better view of the transfer coolant pipe which I also suspected earlier in my investigation. I can't see any signs of leakage and the way the coolant was pouring out, it could not be a small leak. It was running like a tap, so to speak.

Is there any way of testing the HBV now that I have it removed from the car? Would be very satisfying to 100% identify a failed HBV before I set about re-assembly.

Cheers and best regards to all.

MG
Title: Re: Coolant pouring out from rear of engine
Post by: Nick W on 15 September 2020, 14:23:22
I have already started dismantling the car - the plenum and the inlet manifolds are off and I have fully inspected all of the heater hoses at the rear. I have identified the HBV and have ordered a replacement from autodoc (which I hope is an OK firm to use).

I can't therefore try Doctor Gollum's test as the car is a bit in pieces at the moment - guess I was a little enthusiastic to try and find a split hose or similar ::)

Is there any way of testing the HBV now that I have it removed from the car? Would be very satisfying to 100% identify a failed HBV before I set about re-assembly.



it's such a common failure, that if you've got it off putting it back isn't worth the £15(or less) saving
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 15 September 2020, 14:32:19
I have already started dismantling the car - the plenum and the inlet manifolds are off and I have fully inspected all of the heater hoses at the rear. I have identified the HBV and have ordered a replacement from autodoc (which I hope is an OK firm to use).

I can't therefore try Doctor Gollum's test as the car is a bit in pieces at the moment - guess I was a little enthusiastic to try and find a split hose or similar ::)

Is there any way of testing the HBV now that I have it removed from the car? Would be very satisfying to 100% identify a failed HBV before I set about re-assembly.



it's such a common failure, that if you've got it off putting it back isn't worth the £15(or less) saving
This :y

If it's almost out, throw a new one in  ;)
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 15 September 2020, 15:25:20
OK many thanks for your encouragement :y

BTW I mean't to ask is there a part number for the elbow seals and where may I obtain them?

Regards,

MG
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 15 September 2020, 15:32:13
Dowty washers, from VX with new banjo bolts :y
Title: Re: Coolant pouring out from rear of engine
Post by: woolley11 on 15 September 2020, 20:50:31
Could be the coolant transfer pipe at rear which is over the bell housing.

There’s a little seal on that that goes brittle/breaks up. A bit of a pig to get to but if you’ve removed plenum etc should be visible. 2 hex bolts and 1 near exhaust O/S heat shield.


Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 15 September 2020, 22:48:38
Never touchedthe coolant bridge on my 285k 3.2... Did have at least 2 hbvs in the six or so years I had it for ;)
Title: Re: Coolant pouring out from rear of engine
Post by: Migv6 le Frog Fan on 16 September 2020, 00:00:38
Im tempting fate here, but mine has been fine in the four + years Ive has it. I have one or two spare HBV,s in the shed, so ni biggy of it lets go.
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 16 September 2020, 00:06:44
Im tempting fate here, but mine has been fine in the four + years Ive has it. I have one or two spare HBV,s in the shed, so ni biggy of it lets go.
The do about 80k, so you should be ok for another four :D
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 17 September 2020, 09:14:20
Thanks for that - I will order the Dowty's - hopefully can source them OK.


HBV en route from Germany at the moment!

Cheers,

MG
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 17 September 2020, 09:27:48
Hi

I have had a look around for  Vauxhall spares to source these dowty washers and banjo bolts. I can't seem to find any...am I looking in the wrong place!!

MG
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 17 September 2020, 09:53:53
Dowty washers, from VX with new banjo bolts :y
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 17 September 2020, 09:59:57
Thanks Doctor.

I can't seem to source these....maybe I am looking in the wrong place. Can you give me a website please?

The bolts themselves look OK, however on one bolt the top rubber seal is split and may have been leaking. Is it possible to get rubber washers and the metal washers and re-use the old bolts?

Thanks for all your help.

Regards.

Mel.
Title: Re: Coolant pouring out from rear of engine
Post by: henryd on 17 September 2020, 10:07:32
Thanks Doctor.

I can't seem to source these....maybe I am looking in the wrong place. Can you give me a website please?

The bolts themselves look OK, however on one bolt the top rubber seal is split and may have been leaking. Is it possible to get rubber washers and the metal washers and re-use the old bolts?

Thanks for all your help.

Regards.

Mel.
https://uk.rs-online.com/web/c/pneumatics-hydraulics-power-transmission/power-transmission-gaskets-seals-packings/seals-o-rings/?applied-dimensions=4294532979
In bags of 50 but not a fortune   
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 17 September 2020, 10:16:40
Thanks Doctor.

I can't seem to source these....maybe I am looking in the wrong place. Can you give me a website please?

The bolts themselves look OK, however on one bolt the top rubber seal is split and may have been leaking. Is it possible to get rubber washers and the metal washers and re-use the old bolts?

Thanks for all your help.

Regards.

Mel.
Obviously wasn't clear enough... Go to Vauxhall and buy some...

Or buy the bag full that Henry suggested  :D
Title: Re: Coolant pouring out from rear of engine
Post by: Nick W on 17 September 2020, 10:54:27
Or take one of them to a hydraulic/pneumatic/fastening/bearing supplier and get them for a few pence each. If you don't bore the counterman with what you want them for, he might not bother charging you at all. This will give you fewer spares than a bag of 50 ;D
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 17 September 2020, 12:04:55
Thanks again!

@Henry: have ordered the RS ones (16.7 x 24 mm) are the perfect match to mine. Guess I will have 46 spares!!

@Doctor Gollum: Did try Vauxhall and it is a real pain to get parts - didn't get anywhere. The nearest Vauxhall dealer really only wants to sell new cars not old ladies like the Omega!! Do you use a particular tame dealer that has a decent parts person that is willing to spend time looking up parts for future reference.

Hopefully get the old girl up and running soon  :)

Cheers,

Mel.
Title: Re: Coolant pouring out from rear of engine
Post by: Doctor Gollum on 17 September 2020, 12:48:38
I used to have a tame dealer, but long since gone :'(

Now Vauxhall in Weybridge were always pretty helpful, but equally I have never been afraid to obtain genuine parts from overseas. Obviously it helps to have a part number...

May be worth having a sit down chat with the dealer principle/Aftersales manager, but don't expect much :-\
Title: Re: Coolant pouring out from rear of engine
Post by: MG on 18 September 2020, 10:03:13
Thanks for all your help. Much obliged.

Hopefully get the Dowty washers today. The HBV seems to still be in Germany....I guess Covid will slow it's delivery. Was hoping to get it buttoned up over the weekend but more likely next weekend now.

Will let you know how I get on.

All the best.

Regards,

Mel.