Where is the bleed valve for the Saxo heater matrix

MULTIMENTAL · Unread post by **MULTIMENTAL** » 15 Dec 2010, 11:10

My first post so drinks are on me.

I've recently bought a 99 1.5d Saxo.

Had to drain the coolant as there was no antifreeze in the system.

Now I've refilled it complete with antifreeze but there is no hot air coming out of the heater.

I'm assuming that there is a valve somewhere to release the air from the matrix.

Thanks in advance.

Unread post by **CitroJim** » 15 Dec 2010, 11:29

Welcome to the forum

I can't say specifically for the Diesel Saxo but on the petrol ones there is a bleed valve right on the elbow by the matrix connector.

petrol Saxos are a bit of a trial to bleed as the expansion tank is lower than the topmost parts of the cooling system. There are three bleed valves, one on top of the rad, one on the thermostat housing and one on the matrix elbow.

Fill with them all open and observe that coolant flows out of them all, especially the rad and thermostat housing.

MULTIMENTAL · Unread post by **MULTIMENTAL** » 15 Dec 2010, 11:42

Cheers Jim.

I couldn't see an elbow as such, just a straight pipe dissapearing into the bulkhead.

Is the valve visable without removing anything?

spider · Unread post by **spider** » 15 Dec 2010, 12:40

Again from memory as its been a few years, there is usually one on the radiator (passenger side, right on the top) and one on the hose near the back of the cambelt, it pokes up into almost a U bend shape has a tyre valve type cap on that one. You cannot miss it.

Unread post by **CitroJim** » 15 Dec 2010, 12:40

MULTIMENTAL wrote: Is the valve visable without removing anything?

It should be. I would expect to see two pipes running together through the bulkhead to the matrix.

One of the pipes should have the valve on it, either looking like a small wheel or more possibly like a tyre valve cap. If the latter, take care as they can pop off if unscrewed too far and be lost. Although they look like a tyre valve cap, they are in fact a bit different.

MULTIMENTAL · Unread post by **MULTIMENTAL** » 15 Dec 2010, 13:09

Thanks again Jim and Andy Will have a look by candle light tonight when I get home. Which incidently is an advantage of not having a petrol engine.

Unread post by **CitroJim** » 15 Dec 2010, 13:43

Thinking a bit more about this, if you refilled without cracking open any bleed valves then you may well have a very significant airlock in the cooling system.

This air lock may be stopping coolant flowing around the radiator as well as the matrix. In this current cool weather and the generally cool running of a diesel, this may not be immediately obvious.

So, bleed the system fully and bring the engine up to full operating temperature whilst checking that the top hose gets hot when the thermostat opens and that the radiator is warm all over.

As the expansion tank is lower than the top of the system, bleeding is assisted greatly by using an old 2L coke bottle with the bottom cut out to act as a secondary header tank. The neck of the coke bottle can be sealed into the expansion tank filler neck with blu tak or plasticine.

Ensure the bleed valves on the top of the radiator and thermostat housing expels plenty of coolant. You then know both the engine and rad are full of coolant.

Run the engine, with header tank in place until the cooling fans cut in and out again.

Do not replace the cap on the expansion tank until the engine has cooled down.

MULTIMENTAL · Unread post by **MULTIMENTAL** » 15 Dec 2010, 16:07

The rad and the top hose are getting hot no probs it's only the heater that isn't getting hot so hopefully a good bleed will sort it out.