thermostat change xantia 1.8 16v 1996

_kid_ · Post by **_kid_** » 10 Apr 2006, 23:18

I am looking at changing the stat soon, however the picture in Haynes are for the 2.0 8v engine (great!) so im unsure of a few (a lot) of specific queries.

1)where is the thermostat? - is it on the left hand side of the head, near the blue, brown and green switches, where the top hose leads into the engine

2) I cant see any lower hoses, in the Haynes manual it states press down the clips at the top of the radiator and push the radiator forward there will be some lower hoses on the other side of the radiator, is this correct?

3) Where is the drain screw at the bottom of the radiator, i can’t see it?

4) Bleed screws, again the pictures are totally different, anyone gives any ideas where they are on this engine.

AndersDK · Post by **AndersDK** » 11 Apr 2006, 01:38

1) exactly there. Under the elbow piece which connects to the top hose. The stat would be retained by a circlip. Remember a new gasket for the stat, as this also is the gasket seal for the elbow.

2) It is there - hidden. My advice is to leave it - as it is a pig to re-connect

3) Haynes usually shows som very nice drain taps on radiators. I've only ever seen it on one of my old Austin Maxi's - and is was stuck solid by rust. Try if there is a plug-like device with a fin which can be twisted ccw. This will have sort of a bajonet coupling with a seal and drains the fluid.

4) a similar plug may be found on top of radiator either end. Depending on exact production run there are various bleed screws. Just above the elbow - and between the 2 sensors. These are usually hex insert screws. Never torque, just tighten them again.

jeremy · Post by **jeremy** » 11 Apr 2006, 08:36

To change a thermostat you don't need to drain the cooling system - just undo the thermostat housing and it'll do the job for you. You can wash any spillages off your spotless engine afterwards and refill the cooling system with antifreeze solution. DO remember to bleed it carefully before driving avay.

_kid_ · Post by **_kid_** » 12 Apr 2006, 19:14

Thanks for the replies, unfortunately I have some more questions

Ive taken the stat off and lots of water (as expected) come out of the top hose and block side. Later I saw what was a screw type device on the radiator i started turning and sure enough dirty coolant started flowing through.! A little belatedly i found the drain plug!

So the situation is I’ll go to gsf replace the stat and put it all back together, then flush the system with some water. As it was very murky, despite me paying someone only two years ago to have it flushed and changed, by a so-called Citroen specialist

Back to the bleed screws, ive found one near the bulkhead. The only other item i can find is best described as a T shaped bar (with Allen key ends) above the thermostat housing in two ends, is this the other bleed screw(s)?

Also do i need to take the whole screw off until air free coolant flows through, or do i just need to loosen it?

Finally when i pull the radiator from its two clips at the top, there appears to be another radiator, is this the air con rad or something else?

_kid_ · Post by **_kid_** » 18 Apr 2006, 14:05

More problems

Ok ive changed the stat, put a 50; 50 mixture of bluecol ethylene glycol and water, now looks and smells and tastes much better

however im not 100% happy with the heater, its not as good as before.

When i put the heater on 26c it's pumping out lots of hot, and cool on 18c.
Previously on 22c there was warmth coming through the vents, now its much cooler at this temp.

I have followed the advice from previous posts on other threads. Ive opened up 3 bleed screws (two on a t-bar device above the stat) and one on a thick hose (heater hose i think) on the bulkhead.

The two bleed screws on the stat come clear of air quickly. The screw on the hose does flow coolant but only in drops. Ive used the header tank, tried doing it with the car on a slope with the header tank at the highest point and giving some revs. The heater hoses are both hot.

So where do i go? is there air in system despite coolant following out of the bleed screws? if yes, how do i get it out?

oscarloco · Post by **oscarloco** » 18 Apr 2006, 17:53

_kid_ wrote:More problems

Ok ive changed the stat, put a 50; 50 mixture of bluecol ethylene glycol and water, now looks and smells and tastes much better however im not 100% happy with the heater, its not as good as before.

When i put the heater on 26c it's pumping out lots of hot, and cool on 18c.
Previously on 22c there was warmth coming through the vents, now its much cooler at this temp.

I have followed the advice from previous posts on other threads. Ive opened up 3 bleed screws (two on a t-bar device above the stat) and one on a thick hose (heater hose i think) on the bulkhead.

The two bleed screws on the stat come clear of air quickly. The screw on the hose does flow coolant but only in drops. Ive used the header tank, tried doing it with the car on a slope with the header tank at the highest point and giving some revs. The heater hoses are both hot.

So where do i go? is there air in system despite coolant following out of the bleed screws? if yes, how do i get it out?

One question, are you having overheating problems? This would be a sure sign of an air pocket.

Also, did you opened the air bleed on the heater matrix? One way I found that get's the air out of the heater matrix is opening the bleed and blowing inside the rad with your mouth. The pressure is enough to expel all the air from the matrix.

_kid_ · Post by **_kid_** » 18 Apr 2006, 18:00

One question, are you having overheating problems? This would be a sure sign of an air pocket.

no problems re. overheating etc, fans come on as they should.

Also, did you opened the air bleed on the heater matrix? One way I found that get's the air out of the heater matrix is opening the bleed and blowing inside the rad with your mouth. The pressure is enough to expel all the air from the matrix.

where is this air bleed?

oscarloco · Post by **oscarloco** » 18 Apr 2006, 19:11

_kid_ wrote:
One question, are you having overheating problems? This would be a sure sign of an air pocket.
no problems re. overheating etc, fans come on as they should.

Also, did you opened the air bleed on the heater matrix? One way I found that get's the air out of the heater matrix is opening the bleed and blowing inside the rad with your mouth. The pressure is enough to expel all the air from the matrix.
where is this air bleed?

This is usually located in the bulkhead. There should be 2 hoses going into the cabin. You open this bleed screw and also the rad cap. Blow into the rad with your mouth. Water should come out, along with any air stuck in the system.

Good luck!

and remember to wash your mouth afterwards and avoid swallowing, it can be dangerous.

_kid_ · Post by **_kid_** » 19 Apr 2006, 14:02

This is usually located in the bulkhead. There should be 2 hoses going into the cabin. You open this bleed screw and also the rad cap. Blow into the rad with your mouth. Water should come out, along with any air stuck in the system.

Good luck! and remember to wash your mouth afterwards and avoid swallowing, it can be dangerous.

i believe the screw i have opened is this one you are talking about, two pipes next to each other, one with the bleed screw (like a tyre valve), but i still can't get the air out and my rad has no cap, only the expansion tank.

oscarloco · Post by **oscarloco** » 19 Apr 2006, 15:05

_kid_ wrote:
This is usually located in the bulkhead. There should be 2 hoses going into the cabin. You open this bleed screw and also the rad cap. Blow into the rad with your mouth. Water should come out, along with any air stuck in the system.

Good luck! and remember to wash your mouth afterwards and avoid swallowing, it can be dangerous.
i believe the screw i have opened is this one you are talking about, two pipes next to each other, one with the bleed screw (like a tyre valve), but i still can't get the air out and my rad has no cap, only the expansion tank.

That's the one. You could try blowing into the expasion tank. It may work.