Vauxhall vectra pressure build up

[Kelgrim]

I have a Vauxhall vectra 1.8 Petrie 2006, the thermostat has been changed and the hose from thermostat to rad and been change due to it having blown. Now my husband is saying it is building pressure in the coolent tank, it is kicking out really hot air consistently so heating is good, it’s not over heating on the gage (its 90-93) but my husband is saying it is building pressure?? There is no milky stuff so don’t thinks it’s the head gasket but we are stuck on what it could be. Any help please

• *update***

Temperature got to 97 and thermostat opened for the first time since it been replaced, water level has gone down and the hose we replace that he was worried about ha gone hard. So fingers crossed it is ok
Thank you for all your comments

Edited by Kelgrim on Wednesday 14th March 22:09

[Quavers]

Faulty pressure cap?

[HustleRussell]

The system is supposed to pressurise. The expansion cap is a relief valve which will vent if the pressure exceeds a specified maximum.

[GreenV8S]

Kelgrim said:

it is building pressure in the coolent tank

Could you explain what this means? For example, perhaps you mean there is water/steam coming out past the pressure cap when the vehicle gets up to temperature.

[Kelgrim]

Kelgrim said:

I have a Vauxhall vectra 1.8 Petrie 2006, the thermostat has been changed and the hose from thermostat to rad and been change due to it having blown. Now my husband is saying it is building pressure in the coolent tank, it is kicking out really hot air consistently so heating is good, it’s not over heating on the gage (its 90-93) but my husband is saying it is building pressure?? There is no milky stuff so don’t thinks it’s the head gasket but we are stuck on what it could be. Any help please

Bubbling in the tank but the coolant not going down in its place.?? So he is saying if it was air bubbles the coolant won’t go down to take its place

[Mignon]

If it isn't overheating on the gauge and it isn't losing coolant then it's probably fine. Chances are your husband is noticing something in the coolant tank he'd never spotted before and doesn't realise is normal. It isn't uncommon to get localised hot spots inside an engine which boil small amounts of coolant so you get bubbles in the expansion tank as this steam condenses back to fluid.

[Kelgrim]

Kelgrim said:

Bubbling in the tank but the coolant not going down in its place.?? So he is saying if it was air bubbles the coolant won’t go down to take its place

Yes that is what he is saying

[Kelgrim]

Kelgrim said:

Kelgrim said:

Bubbling in the tank but the coolant not going down in its place.?? So he is saying if it was air bubbles the coolant won’t go down to take its place

Yes that is what he is saying

Sorry no he is saying if it was air bubbles the coolant would go down to take it place

[Kelgrim]

GreenV8S said:

Could you explain what this means? For example, perhaps you mean there is water/steam coming out past the pressure cap when the vehicle gets up to temperature.

Ok so now he is saying that it’s builder pressure but there there is bubbles in the tank but the water isn’t going down.

[stevieturbo]

Tell him to ensure system is filled correctly when cold.....screw the lid on correctly and stop trying to look at it with the cap removed when hot.

And all cooling systems operate with pressure in the system when warm.

[Kelgrim]

• *update***

Water level as gone down, he also put a new thermostat in it and didn’t get it up to temperature so the thermostat opened now he has got it up and the thermostat has opened the water level has gone down the new hose we replaced it hard and the water is running ok so fingers crossed it just needed to have the thermostat opened at 97%. Thank you all for your comments xx