306 V6 Will Not Bleed!

[dave205 19]

As above really, 306 with a v6 up front, a standard 406 rad has been used, ive used a 205 header tank with one hose connection on the bottom, fill the bottle, open the rad bleed till water shows then close it, then open the 2 small bleeds on the stat housing and pipework until they show water then close them. Refill the header tank put the cap amd let it run. Temp reached 95-100 degrees with no sign of stopping climbing so i turned it off. Opened the header tank and it emptied itself in seconds and then opened the bleeds n they spewed steam for a minute or so.

 

So after that long explanation, few questions, will it have caused damaged? Also where am i going wrong?

 

Heaters blew cold continually aswell.

 

So frustrated its the last thing on my list of jobs! :/

[welshpug 1,657]

did you not bleed the heater pipe?

[Slo 283 1 Cars]

If your heaters are cold its possibly 3 things, blocked heater matrix, stuck shut thermostat, waterpump knackered internally.

[dave205 19]

did you not bleed the heater pipe?

No theres no bleed on it

[Paul_13 212 1 Cars]

Thermostats probably opened and the system has basically filled up

[Alastairh 47]

Try leaving the cap off for longer. With a 8 valve you can get away with leaving the cap off, taking it for a quick spin and once upto thermostat temperature then put the cap on with no further issues.

 

Al

[dave205 19]

No theres no bleed on it

Ignore that, the little hose and bleed on the matrix hoses was tucked up out of view and it was getting dark so couldnt see it :/

If your heaters are cold its possibly 3 things, blocked heater matrix, stuck shut thermostat, waterpump knackered internally.

Ive had the stat out and tested it with a ketlle of boiling water

Thermostats probably opened and the system has basically filled up

What do you mean?

[dave205 19]

Try leaving the cap off for longer. With a 8 valve you can get away with leaving the cap off, taking it for a quick spin and once upto thermostat temperature then put the cap on with no further issues.

 

Al

I tried that the first time i bled it, but it just spewed water after a few minutes

[Slo 283 1 Cars]

If your heater is cold when the lump is hot are the pipes warm under the dash? Have you tried disconnecting both in the engine bay and blow down one to see if anything comes out the other side? It will rule out the matrix being blocked but not your over heating issue. I suspect your waterpump personally especially if your thermostat is known good.

[Paul_13 212 1 Cars]

When I've filled the coolant in the past, firstly I filled the header tank til full.

Then bled all the bleed points in the engine bay and fill the header tank again.

Started the engine and waited for the thermostat to open. At this point the coolant will fill the block fully.

I then turn the engine off, refill the header tank (when it's cooled down a bit) and rebleed the system and topping it up as necessary.

Edited September 25, 2013 by Paul_13

[Henry Yorke 269 3 Cars]

What I think is being said is that when the thermostat is shut the water cannot get from the headertank to the rad. Once the thermostat opens, the water runs from the main cooling system into the radiator to fill it, leaving your header tank empty.

 

As Al & Paul say, I would fill the header tank, run up to temp, wait til the water level drops when the stat opens & rad fills, turn off and let it cool, then top up again, then bleed.

 

Pipes to the top of the rad should get warm, as should the heater matrix ones. Squeezing pipes should make the level in the header tank raise too.

[Goliath 94]

How do you have the pipes routed?

You need a bleed pipe from the top of the rad to the top of the header tank.

[Slo 283 1 Cars]

The heater matrix is plumbed in a way that bypass's the thermostat altogether so there should always be water passing through it (unless the controls are set to cold obviously), this is to demist the windscreen before the engine warms up enough to open the thermostat. This is why i suggested the pump maybe suspect especially since its boiling hot in the header tank.

Edited September 25, 2013 by Slo

[welshpug 1,657]

Settings of heater knobs has no bearing whatsoever on the flow of coolant.

[dave205 19]

Settings of heater knobs has no bearing whatsoever on the flow of coolant.

Correct

[dave205 19]

The heater matrix is plumbed in a way that bypass's the thermostat altogether so there should always be water passing through it (unless the controls are set to cold obviously), this is to demist the windscreen before the engine warms up enough to open the thermostat. This is why i suggested the pump maybe suspect especially since its boiling hot in the header tank.

The heater matrix hoses come off the thermostat housing on the side of the head, and the header tank is plumber straight into the side of the engine/head. How can i test if water is actually moving round the system?

[dave205 19]

When I've filled the coolant in the past, firstly I filled the header tank til full.

Then bled all the bleed points in the engine bay and fill the header tank again.

Started the engine and waited for the thermostat to open. At this point the coolant will fill the block fully.

I then turn the engine off, refill the header tank (when it's cooled down a bit) and rebleed the system and topping it up as necessary.

Thats the method i tried but the problem is it just blows all the water out the header, rather than the level dropping, but im not sure why though

[dave205 19]

What I think is being said is that when the thermostat is shut the water cannot get from the headertank to the rad. Once the thermostat opens, the water runs from the main cooling system into the radiator to fill it, leaving your header tank empty.

 

As Al & Paul say, I would fill the header tank, run up to temp, wait til the water level drops when the stat opens & rad fills, turn off and let it cool, then top up again, then bleed.

 

Pipes to the top of the rad should get warm, as should the heater matrix ones. Squeezing pipes should make the level in the header tank raise too.

The level in the header tank doesnt drop, it rises more and more until it overflows and spews itself empty.

 

Pipes to the rad seem to get hot pretty quick so would that mean water is moving into the rad or not?

 

Im also unsure which pipe comes from the waterpump.

[TooMany2cvs 65]

How do you have everything routed? Are there bleeds on EVERY high point? Is the header tank the highest high point?

[Slo 283 1 Cars]

The heater matrix hoses come off the thermostat housing on the side of the head, and the header tank is plumber straight into the side of the engine/head. How can i test if water is actually moving round the system?

 

Pull off a matrix pipe, hold it up high and start the engine if it flows out you have a matrix problem. As said the matrix pipe are or should be plumbed before the thermostat so coolant will flow through it permanently (as pointed out by welshy ) regardless of thermostat being open or shut.

[dave205 19]

How do you have everything routed? Are there bleeds on EVERY high point? Is the header tank the highest high point?

Matrix hoses to thermostat outlets, the rad hoses to the standard place on the pipes on the side of the engine and the black metal pipe that goes round the back of the engine to the original header Has been shortened and joined to my header on the passenger side.

 

There are 2 bleeds on the therstat housing, one on the top of the rad and one on the matrix hoses.

 

The header tank isnt the highest point.

[welshpug 1,657]

Std header tank? Should be the highest point.

[Slo 283 1 Cars]

You have both matrix hoses to the thermostat housing?

[TooMany2cvs 65]

The header tank isnt the highest point.

Then you're probably going to need to build some kind of a bleed/fill tower to raise the effective water level in the header so it is the highest point.

[dave205 19]

Std header tank? Should be the highest point.

No a base model 205 one, single outlet on the bottom.

You have both matrix hoses to the thermostat housing?

I think so :/