Omega Owners Forum

Chat Area => General Discussion Area => Topic started by: cdx25 on 23 May 2007, 14:03:01

Title: HBV failing - early warning
Post by: cdx25 on 23 May 2007, 14:03:01
Just thought Id post what may have been an early warning sign that I had on my cdx just before it coughed out all that new antifreeze over the road... >:(

The A/C was recharged as soon as I got the car about 6 weeks ago... and it was great, until about 2 weeks ago when it seemed to lose its ability to cool.  It *was* working, but it wasnt great.  Then it went a bt intermittent - sometimes it would blow cold, sometimes only cool.

Then last night the 'low coolant' warning came on... this morning I discovered a drip drip drip from the back of the engine.  So today, HBV out and changed - which seems to have cured leak and AC back to ice cold.   8-)  

Kevin W posted in another thread about HBVs being implicated in poor AC performance - so I thought I'd add this experience in too.

Cheers

Jon
Title: Re: HBV failing - early warning
Post by: STMO123 on 23 May 2007, 14:06:05
No doubt Mark can explain exactly why :)
Title: Re: HBV failing - early warning
Post by: Kevin Wood on 23 May 2007, 14:07:53
I suspect part of the failure mode is that it fails to cut off the flow to the heater matrix, meaning the climate can't cut off the heater completely.

Useful information to know.

Kevin
Title: Re: HBV failing - early warning
Post by: TheBoy on 23 May 2007, 15:03:29
Quote
I suspect part of the failure mode is that it fails to cut off the flow to the heater matrix, meaning the climate can't cut off the heater completely.

Useful information to know.

Kevin
They fail in different ways, but that would be one of them - ie heating the chilled air, hence only coolish air...
Title: Re: HBV failing - early warning
Post by: cdx25 on 23 May 2007, 16:08:34
Quote
I suspect part of the failure mode is that it fails to cut off the flow to the heater matrix, meaning the climate can't cut off the heater completely.

Useful information to know.

Kevin

Yeah - all sounds very plausible doesnt it.  The inside of the valve was a bit crappy and it may well have been sticking...  presumably it cant stick in the 'no flow' position (as there doesnt seem to be one) and then cause damage by overpressurisation.  But odd that mine then starting piddling out coolant shortly afterwards.  Could be unconnected of course...