Another cooling thread!

[wedgewood]

Can anybody offer me some advice. I have just had the radiator refurbed/upgraded, changed swan neck, large pipes, and filled with new coolant. Started up and the temp comes up, fans cut in. All good but the pressure in the top hose seems excessive, to the point that the cap in the swan neck starts bubbling and dripping coolant.All hoses are getting warm so I can't figure what the problem is. I changed both caps, no difference. I am wondering if there is an airlock in the heater. How do I sort this? Thanks in advance for your help.(350i V8, 1984)

Ian

[Chauffeurdude]

Did you move the heater controls to hot setting? Is it blowing hot air from dash vents etc? If you don't have hot air from vents then could be airlock in system.

[wedgewood]

I have moved the heater controls, heat is at best lukewarm (likewise the return heater pipe) i am wondering if it might be the new swan neck, maybe the facing is not flat. I am just worried that i am going to over heat the engine and end up having to do head gaskets etc.

[chedder]

Just a thought, have you vented the radiator? (5/8 nut on the top corner drivers side of the rad)

Chedder

[wedgewood]

Thanks Cheddar.

I'll give that a try.

regards

Ian

[adam quantrill]

The swan neck cap should never leak. It might not be seated properly. I seal mine with blue hylomar (make sure none gets into the watter) and never touch it ever again. If no joy, other people have braised in a plumbing fitting with a screw-fit seal, which is totally reliable.

[jmorgan]

Not sure if the same heater matrix issues with the 350 but on mine (400) the heater pipes go quite high through the bulk head so I fitted a bleed valve to the highest point and this helps to clear airlocks a treat.

[wedgewood]

Thanks guys for your advice, I can't do anything for a couple of days but I will try venting the rad. then seal off the swan neck cap. Never had a problem with coolant changes before, just squeezed the bottom hose and all the air burped out. I think it's just got the hump cos i'm not using it!

[Campbell]

When i have problems cooling problems i drain the system from the lowest point then start to refill from the swan neck pumping the feed pipe to the water pump then when that is full refit the cap start the car and watch for air comimg out of the header.
That should do the trick

[ferlin]

Run car with heater controls on hot and with rad and swan neck caps off then and fill it up from swan neck until it washes over the top. Then fit swan neck cap while its running.
Thats how i have always done mine

[Transmitter Man]

Are you running the correct, high flow thermostat?

Phil
420 SEAC

[ed_crouch]

I heard that there was this High Flow thermostat, but I bought a boggo one, and it was identical to the one I took out. I took the calipers to them, and they were identical...

So I use the boggo one, and it never overheats.

Edited by ed_crouch on Wednesday 15th July 22:42

[wedgewood]

I've had the thermostat in for a couple of years now and it has always been fine, I did take it out and checked it in a saucepan of hot water...all ok (other half not too impressed though!)The stat. is not drilled so there may be some air behind it. I am going to try venting the rad. first as this seems a likely problem area for air locks..it's just finding the time to get on with it!

[Transmitter Man]

In an efficient cooling system one needs as few restrictions as possible - and that includes the thermostat.

If you're works then of course no need to change anything.

I intend replacing everything on my colling system for same or better spec parts, rad, fan, hoses, 'all' stainless clips plus the above thermostat.

Phil
420 SEAC