bleed screws for coolant system'? - HDI DW10

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eurotrotter
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bleed screws for coolant system'? - HDI DW10

Post by eurotrotter »

hey gang

i have changed the coolantin my hdi xsara and I can only locate 1 bleed screw - the one on the bulk head,

i have read everywhere that there is a 2nd bleed screw, but cannot locate it.

the one ont he bulkhead is like a dust cap on a bicycle tube, what does teh 2nd screw look like, and where is it located?

thanks very much, really killing me this one!

here is a pic of my engine bay:

https://picasaweb.google.com/1096236004 ... 8778922802

ed
Last edited by eurotrotter on 27 Mar 2011, 09:25, edited 1 time in total.
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VertVega
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Post by VertVega »

I don't know about diesel models but if any help from a petrol Xantia :)

In mine there are two bleed screws:
1. On the bulk head (plastic cap like in a tyre which you have already found)
2. Thermostat housing (allen key hex) as shown in below pic with green arrow.

Image
Xantia MK2 petrol thermostat housing
C5 II 2.0i 16V - 2005 - Estate - 103KW - EW10A - Petrol - Manual
eurotrotter
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Post by eurotrotter »

hi verta, i think mine is different, i heard that the 2nd bleed screw is another dust cap or a like a bottle cap, so i think its different on the diesels, thanks very much for the pic though
KevMayer
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Post by KevMayer »

The two bleed screws should be:-

Heater Matrix outlet - which is the one you found on the bulk head.

Coolant outlet housing - This one should be on the thermostat housing. If you follow your radiator top hoze back to the engine then the bleed screw should be on top of the housing where this top hoze fits.
Cheers, Kev

02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).

Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
eurotrotter
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Post by eurotrotter »

thanks kev im going down now to test it

il let you knw
eurotrotter
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Post by eurotrotter »

hi kev

i think i found the thermostat:

here are the pics:

https://picasaweb.google.com/1096236004 ... 9764607618

is it the 'gold' colored allen nut that i need to loosen?
eurotrotter
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Post by eurotrotter »

iv just done it there now, and i removed teh dust cap off the bulkhead completely and it pissed out and stopped flowing then so i just screwed it back up, and the gold allen screw on the thermostat pissed a bit out at the start,

is it enough for it to just spurt out about 10ml and stop flowing then

once this is done is the job done or do i need to kick her at 1800rpm until she has a constant flow of coolant?
KevMayer
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Post by KevMayer »

The gold screw looks like the right one.

You need to bleed until you get a constant stream without air bubbles and you usually get this straight away when the coolant starts to come out.

Tighten the bleed screws and then run the engine until the thermostat opens. Usually manuals say run the engine until the cooling fans come on and off twice.

You can tell when the thermostat opens because this is when your top hoze suddenly becomes hot.

What you need to watch for is the height of your expansion tank relative to your highest bleed point.

On my C5 I undo the fixings for my expansion tank and lift it as high as possible. Try to lift your expansion tank. If it's not high enough you'll still have air in the system.

When the fans have run twice let it cool down then top up the level to the mark.
Cheers, Kev

02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).

Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
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VertVega
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Post by VertVega »

I have checked the pic in your link and it is clear that your's also have an allen nut like mine :)
eurotrotter wrote:... , i heard that the 2nd bleed screw is another dust cap or a like a bottle cap, ...
... but also I found a pic of a diesel xsara where the '2nd bleed screw' is like a dust cap 8-)

Image

Edit: I have added both types in above pic, lower one is from your car.
C5 II 2.0i 16V - 2005 - Estate - 103KW - EW10A - Petrol - Manual
eurotrotter
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Post by eurotrotter »

thanks for the help!

the problem is resolved, no more air and temperature has stabilised at 80, BUT nowi have a new problem, u will not believe this but i managed to snap the head off the gold allen screw :(

im freaked now at myself for being so stupid

iis there a tool i can get to drill out the screw or should i just get a new piece?

thanks for your help so far
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Clogzz
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Post by Clogzz »

The Allen screw seizes even if it’s never been overtightened, so it’s not your fault.
On the petrol Xantia, the Allen screw (item 2) is mounted on a tube that turned slightly last time that I tried loosening it.
I turned it back to where it was and it never leaked.
It’s never affected the cooling because hardly any air ever came out of there.

If it doesn’t leak, leave it alone because the seized thread holds the coolant in.
You may slap goo to seal the break, and drive with the header tank cap loose, as I do, to prevent pressurisation.
Proper coolant doesn’t simmer and the HDI is efficient and doesn’t put out much heat, providing that it hasn’t got too much air in the cooling system.
It’s 30 degrees every day here in summer, and I don’t lose any coolant through the loose cap.

Image
2002 C5 2.0i AL4 230,000 km 76372389
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