header tank

[biglamb]

hi all, im new to pugs and this forum. so a big hello.
Right i have just bought a 406 est executive, 2.0 hdi. I have noe user manual for it and i need to know how much water to put in the header tank because the low coolant llight has come on. There does not appear to be a min and max level that i can see and the tank is black. making seeing the leve hard. please can somebody help me. thanks.

[mjb]

You've got a round bit by the cap, and going a bit deeper a rectangular bit. I tend to call half way up the round bit 'good'.

Don't worry about over-filling though, the cap is a pressure valve and will spit out coolant when the pressure gets too great.

[biglamb]

thanks, that helps. when i got the car i did about 200 miles or so then it came on (the coolant light that is). I put about a litre or so in the header ( with the engine cold) but it was not filled the the mark you stated. i just didnt want to over fill it. The light was gone then but now after another 100 miles or so it has come back on but its not pemenant. mainly when traveling at low speed. (prob just a co insidence). So i will now try put some more in. Do you know if there is a common problem with the water works on these things? Thanks again.

[teamster1975]

Do you know if there is a common problem with the water works on these things?

The rads tend to rot on the older cars; yours is an hdi so it must be a D9; how old is it?
Have a look around the hoses and check for any coolant spray; the bottom hose is a weak point; the conrad (poncy word for push-fit ) unions rust away to nothing!

[biglamb]

mines a dec 2001 model ive had a look around and no obvious signs of leaks. but it has had a bit of from end damage in a previous life. but not bad enough to damage the rad. although it has no top fastening points now. so ill keep an eye on the water level now i have topped it up to the correct level. thank for the replies. much appriciated. lots more questions to ask later. as i have no manual for it yet and the executive is full of toys and trickery that i need to tame.

[teamster1975]

Enjoy you car and welcome to the club biglamb!

[Welly]

The biggest problem with HDi's is that they are so reliable no-one bothers to check under the bonnet. If your water level drops naturally over time it's not allways picked up by the sensor and warning light. The trouble here is that the water level is critical to the cooling system on these and overheating of the head can occur and take the head gasket out.

I'm not trying to scare you fella but have a feel of the radiator hoses with the engine hot - if they feel rock hard like they want to burst then the coolant is being pressurised via the head gasket. You should be able to easily squeeze them.

If you are loosing water then hopefuly it's something simple like a leak but also bear in mind the water pump can leak and be difficult to trace - and that thing lives in cambelt land

Welcome by the way