Vauxhall Owners Network Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
245 Posts
Discussion Starter #1
Can anyone tell me the symptoms of this being cracked, am i right in saying

heating blowing cold then the water in the expansion tank will rise and overflow,

heating blowing hot then water will fall

Cheers
 

·
Registered
Joined
·
76 Posts
mine was leaking and besides that i didnt have any other symptoms.... noticed the coolant trail on the side of the transmission whilst under the car...figured then that the bypass valve was the likely culprit for the coolant loss....the valve is cheap so dont worry about the money if your old valve is/was ok. sooner or later they all fail...:D
 

·
Registered
Joined
·
45 Posts
Can anyone tell me the symptoms of this being cracked, am i right in saying

heating blowing cold then the water in the expansion tank will rise and overflow,

heating blowing hot then water will fall

Cheers

Just for my own benefit could you tell me what engine is in ur car And if it has aircon?

I'm having similar problems but I read that only omegas with aircon have the heater bypass valve.

Could someone please say for sure?

Thanks
 

·
Registered
Joined
·
159 Posts
I've done this too, but don't recommend it as a
- the part is cheap from Vx
- its a pain to fit, and the scrappy one may fail imminently.

To confirm ONLY AC cars have HBV.
 

·
Registered
Joined
·
60 Posts
I changed mine too not so long ago, but the major amount of coolant on my drive was the only indicator. If you reach round to the HBV you should feel it wet, when really it shouldn't be. When I took it off I couldn't see any obvious damage or signs of wear, but I replaced it with a new one from Vx and (touch wood) it has been fine since. The leak only occured two days before I was due to take the family on holiday to France ...in the car!
If you're suspicious at all, then just change it. It's a bit fiddly, and you may want to use jubilee/hose clips on reassembly to make it a bit easier.
Good luck!
 

·
Registered
Joined
·
71 Posts
After a run in mine (2.5v6), when i pull up and open the bonnet , i can see the water boiling in the tank , if i go to open the cap it bubbles like it wants to overflow.

Would this be the hbv?

Matt
 

·
Registered
Joined
·
45 Posts
After a run in mine (2.5v6), when i pull up and open the bonnet , i can see the water boiling in the tank , if i go to open the cap it bubbles like it wants to overflow.

Would this be the hbv?

Matt
No that sounds normal to me because when the coolant gets hot it expand creating pressure,

so when you open the cap coolant should overflow due to expansion.

If you have no leak from under the filler cap or any other external leak then you have nothing to worry about.
 
1 - 9 of 9 Posts
Top