Running Cold

[Griffinr]

My S3 just does not get warm this weather, did 100 motorway miles yesterday and the gauge sat just on top of the white band at the bottom of the scale. It does come up a bit more at slow speed or if you tick over stationary but at speed stays cold. Thermostat has been changed twice and tests out OK. Now thinking of partially blanking the rad or the front grill for the winter, has anybody found a satisfactory way of doing this.

Rob.

ps. It was fine all last summer.

[Barkychoc]

Presumably heater is hot?
Could be temp gauge sender quite a common fault on the fords the engine came from.

[Griffinr]

Barkychoc said:

Presumably heater is hot?
Could be temp gauge sender quite a common fault on the fords the engine came from.

Heater is barely warm, temperature does come up if you allow it to tick over for a while so the gauge and sender are OK and both the stats I have had fitted tested ok. There seems to be quite a lot of circulation into the rad even with the stat shut, this is through the smaller hoses that go into the swirl pot.

Rob.

[ketvrin]

If you bring it up to temperature when stationary does it get to the point where the fan cuts in or not? If it does, take it for a drive and see if the temparatue plummets, in which case partially blank your vents, a bit at a time intil you are happy...

you might find that once it has been brought up to temperature it will stay reasonably normal thereafter...

K

[Jed-S]

Griffinr said:

There seems to be quite a lot of circulation into the rad even with the stat shut, this is through the smaller hoses that go into the swirl pot.

Rob.

So it isn't just mine doing this then. I was looking at it the other weekend trying to determine why there is a lot of water going through the rad when the stat is shut. To make matters worse for me I have an alloy rad that seems better at cooling than the original one.

I'm begining to think that the design of the cooling system is flawed but haven't had a chance to look at the coolant flow on the donor vehicles.

[tozerman]

Jed-S said:

So it isn't just mine doing this then. I was looking at it the other weekend trying to determine why there is a lot of water going through the rad when the stat is shut.

I have always wondered about this,what I think is causing it is the pipe that goes from the water pump straight to the swirl pot and obviously then to the radiator thereby missing the stat altogether and causing longer warm up times !!!
Cheers.....Tony..

[Griffinr]

Jed-S said:

I'm begining to think that the design of the cooling system is flawed but haven't had a chance to look at the coolant flow on the donor vehicles.

I think there is a flow diagram in Steve Heaths book, I'll have a look tonight and see if I can work it out.

[Griffinr]

tozerman said:

I have always wondered about this,what I think is causing it is the pipe that goes from the water pump straight to the swirl pot and obviously then to the radiator thereby missing the stat altogether and causing longer warm up times !!!
Cheers.....Tony..

My thoughts also, I wonder where this pipe went to on the granada? I'll have a look in that manual too.

[Jed-S]

Griffinr said:

I think there is a flow diagram in Steve Heaths book, I'll have a look tonight and see if I can work it out.

I wouldn't bother looking - it isn't worth the paper it is printed on. It doesn't even have a swirl pot on the diagram.


Maybe it is time to re-plumb the car and get rid of the swirlpot and fit a header tank in its place. If the pipe from the thermostat housing goes straight to the upper rad pipe and the small 10mm (?) pipe from the pump goes to the lower rad pipe and also has a T that goes to the header tank. That's my initial thought from the warmth of my living room but it might have to change when I get my head under the bonnet again.

[Griffinr]

Jed-S said:

I wouldn't bother looking - it isn't worth the paper it is printed on. It doesn't even have a swirl pot on the diagram.


Maybe it is time to re-plumb the car and get rid of the swirlpot and fit a header tank in its place. If the pipe from the thermostat housing goes straight to the upper rad pipe and the small 10mm (?) pipe from the pump goes to the lower rad pipe and also has a T that goes to the header tank. That's my initial thought from the warmth of my living room but it might have to change when I get my head under the bonnet again.

I think your right, reading the Granada manual it appears that the water pump bypass pipe goes to the header tank. The feed from the header is them connected to the bottom of the rad. My thinking is to put a tee into the bottom hose to take the bypass and then blank off the spare connection on the swirl pot. Bit of a tortuous pipe route though.

Rob.

[tozerman]

tozerman said:

I have always wondered about this,what I think is causing it is the pipe that goes from the water pump straight to the swirl pot and obviously then to the radiator thereby missing the stat altogether and causing longer warm up times !!!
Cheers.....Tony..

Trying to think about it logically, the only way this hose can be justified is if on a granada it goes straight to the radiator, the only way to be sure is to try it without that hose connected and the two 16mm unions blanked off and see what happens although I'm not brave enough to try it

Cheers.....Tony..

[Griffinr]

tozerman said:

Trying to think about it logically, the only way this hose can be justified is if on a granada it goes straight to the radiator, the only way to be sure is to try it without that hose connected and the two 16mm unions blanked off and see what happens although I'm not brave enough to try it

Cheers.....Tony..

I think it is required to take the load off the pump when the thermostat is closed.

Rob.

[GreenV8S]

I haven't look at that circuit, but from the sound of it that hose you refer to is used to vent the pump. I'd view it as a design fault to have this connected from the pump outlet to the top hose since that effectively bypasses the stat. Is it actually required - does the pump have any other way of venting? If you do need it, it would be better to feed into the hearer circuit rather than the top hose. If you decide to keep it connected into the top hose, you could afford it to be quite restrictive since it's only really needed when filling the system, and would be flowing air rather than water. I'd try clamping that hose off and see if the cool running problems stop.

[ketvrin]

It feeds the heater circuit at High pressure when the Stat is closed and low pressure when the stat is open according to the diagram, but what if the stat is closed and the heater valve is off too ?

K

[GreenV8S]

On the V8S, there's an H joint between the two heater pipes so that the heater circuit still flows even when the control valve is 'off'. Is it the same on the V6 ones?

[tubbystu]

GreenV8S said:

On the V8S, there's an H joint between the two heater pipes so that the heater circuit still flows even when the control valve is 'off'. Is it the same on the V6 ones?

C'mon Peter, its probably not the same on any two V8S's, let alone to expect it on the V6's too

[Gerald-TVR]

GreenV8S said:

On the V8S, there's an H joint between the two heater pipes so that the heater circuit still flows even when the control valve is 'off'. Is it the same on the V6 ones?

Nope

[KEVINTHEGERBIL]

My V6 stays very cold also, even after some fruity B road driving, has a new rad, I remember be done an update to the heater pipes on my mk2 golf years ago to stop the pressure build up in the heater matrix.
What is the purpose of the swirl pot? What pros n cons when people remove them?

[jimed]

My old S3C was well behaved in the summer but in the cold weather it did tend to sit towards the bottom of the temp gauge unless in traffic. I tried a couple of thermostats in case that was the problem but no change - I suspect that as the rad had been recored and I'd given it a good flush at that time it was cooling quite well. It didn't get too much use in the winter and from memory the heater did manage to pop the odd calory out so no huge issue there - that is apart from the fuel consumption - in the summer it would be about 30 on a run but I went to the IoMan in it in April a few years ago and it was quite cold with the temp guage not getting very high for most of it and the fuel comsumption was awful - around 19/20mpg from what I remember so if you are planning on using the car much in the winter some sort of radiator baffle could be useful; not sure how you would do that easily though unless something hung over the rad which could be easily removed?
Jim

[Griffinr]

Thanks for the replies, I think we have established that all the V6 cars run too cold in the winter if the rad and water system are in good condition. I’m also pretty sure that this is due to the bypass hose being connected to the swirl pot. I will have a closer look at the weekend (weather permitting) and maybe try a bit of re-plumbing. Will keep you posted.

Rob.