Air locks in cooling system

[jenny]

Hi,

Can anyone help me - I am a bit stuck

Last week I noticed the water temp in the sumo getting a bit high - its a Rover 3.5v8, usually runs between 80 and 90 - it was up at 110.

The fan wasn't cutting in so I initially replaced the sensor, still nothing The replaced the water pump as I thought maybe that wasn't pushing the water round, still the same problem

£100 worth of spare parts I didn't need later and I decided to start the engine with the top off the header tank. Ran it for a while and a load of air started appearing and forcing itself out of the header tank. Kept topping it up and eventually bled all the air out - lo and behold, the fan now works and the water temp back down to 80.

Drove for a week with temp ok and stable at 80, this lasted until last night when we decided to go for a spin, temp back up to 110 and the fan not working, air in the cooling system again stopping the water from circulating :angry:

I have checked all the connections, there are no leaks and I am really baffled as to why this air keeps getting in, anyone got any suggestions?

Thank you

[neil still building it]

hi

could be a few things first: YOU ARE USING ANTIFREEZE ALWAYS!!!
yes? if not very naughty ....!these engines being ALL alloy mixed with steel ,copper etc in the water system components must ALWAYS have antifreeze in ....ALWAYS ...
was that clear enough for everyone reading this..?if you don't HEAD gaskets etc,etc much trouble ...
back to the plot: you 'll be needing to check for any minute leaks on the block ,rad water pump ..these can let in air and not leak out but there could be a tell tale weep? fix it ..(common fault on golfs -the thermostat housing weeps a little you don't notice (much if at all?) then it draws air in you need to top up and its overflowing (even a relatively cool engine)like mount vesuvious...so look for weeping around the pump /thermostat area especially.
do you have an expansion bottle mounted nice and high up fed oof the top of the inlet manifold -if not add one (the old su's type have this normally can't seem to remember a bout holleys and offe types )without this you've nowhere for the air to collect /dissipate to
try this and do let us know the outcome...
good luck
NEIL

[jenny]

Hi Neil.

Just been home at lunch and bled out the remaining air. There were only a couple of little bubbles and once they were out the fan started working again. I have a feeling that when we brought the car it didn't have anti freeze in it and I didn't really get round to putting any in (new toy, just went out and drove the thing ) Well and truly topped up with Anti freeze now

Will give it a good going over at the weekend - I think it's due for a 'Jenny's special' service

Will let you know what happens

[maxGD059]

Heaters are excellent places for hiding air pockets that reappear at odd times. I have put 2 additional bleed valves (from central heating piping) in the heater inlet & outlet hoses to get those pesky air bubbles out when filling the system. Just put the header tank up high, open the bleed valves & it's all bled in a few minutes.

BTW what's 'a Jenny's special' service

[jenny]

A 'Jenny special' service is where I attempt to fix anything that might be going wrong usually using a combination of quick steel and superglue

It definately needs a bit of tinkering this weekend, I am sure I have got all the air out of the water system - will go for a nice slow drive tonight to make sure

P.S does anyone who lives in the Camberley area fill up at the Tesco Meadows petrol station? If so, have you spoken to that absolute nutter of a security guard there who stands by the pump "I used to have one of those you know, a real shelby cobra... how fast does it go?" Oh yeah, thats why you are now working as a security guard at a filling station :finger:

[gwak76]

Originally Posted by jenny

P.S does anyone who lives in the Camberley area fill up at the Tesco Meadows petrol station? If so, have you spoken to that absolute nutter of a security guard there who stands by the pump "I used to have one of those you know, a real shelby cobra... how fast does it go?" Oh yeah, thats why you are now working as a security guard at a filling station :finger:

FYI, he has brothers who work at McDonalds, Safeway and Tesco, they also had the real thing, so few cars made, so many who owned them

[dave.n]

Jenny

Did you not know that "back in the day" everyones Uncle or Dad owned a real one.


I always answer that some modern day replicas are faster, handle better and also have the capability to stop. Once more this car is mine and it makes me very happy. :finger:

[Alaska Gray]

Ask em about the merits of the 427 engine they normally tie them selves up in knotts then

Graham

[jenny]

Hello,

Just to let you all know that the air lock problem is now fixed. Just bled it out (took about an hour) then filled with antifreeze and some of this 'special stuff' from the local dodgy car spares place. Went for a 'slow' drive on Saturday night about 2am and didn't have any problems

Thanks for the help and advice :thumb:

[tony c]

That's the good thing about being a girl. If we went for a slow drive around Camberley at 2am on a Saturday night we would be arrested for kerb crawling.