Hi there,

 

Having had quite a scare at the weekend (see previous threads) I'm still trying to piece together how things came to be. Not in the 'why are we here, do we really exist sense', but more to do with the water level in my cooling system.

 

As i mentioned befor, when i bought the car - early may - there was nothing to suggest any issues. The car didn't run hot, the heater worked and everything seemed fine. Now I must point out I was foolishly checking the level in the expansion bottle and had not checked the rad level (:clown: I know, I know). So its possible the fluid level could have been a little low to start with.

 

I guess this because now, with rad full, the average operating temp is 5 degrees lower than befor (75-80 degrees) - despite the warmer weather at the mo.. That said, I've only just got the suspension gremlins sorted so I hadn't driven the car hard other than a quick blat up through the gears every now and then. I've probably done less than a 1000 miles to date.

 

At the weekend though I was giving it some stick and things quickly got hot under the collar. One minute everything appeared normal - the next temps were getting very erratic.

 

My theory is that as there was insufficient water in the system from the off; the air in the rad got super heated and therefor released the pressure valve in the rad cap, slowly pushing out what little water there was until the level became critical.

 

Since I filled the system I've noted the cooler water temp but also that there does not seem to be any leaks. I've driven about 200 miles since doing so, 30 of which I was really giving it some. I checked the level in the rad again tonight and its almost full to the brim. I think some fluid must have been pushed out, but then I did over-fill it. The level now is just at the bottom of the rad cap neck..

 

So I think I know how the water got out, but I'm still tryin to figure out why it was low in the first place. When you fill the cooling system and the engine is cold, does the thermostat prevent you getting a substantial amount of fluid in? I.E: did the last person who did this unwittingly think they had filled it, but infact had just filled the rad and not the entire sytem?

 

If this isn't the case then I'm stumped - and in trouble, largely because it is using water and I've no idea where its going (unless it is the rad cap at fault).. I will continue to check the level now, but its a little early to be 100% sure about anything (I'm still waiting for the reprecussions from seeing the wrong side of 150 degrees).

 

Your thoughts would be appreciated - Cheers

A couple of other points I forgot in earlier posts

 

If you still have air con then switch to max in econ mode .... this opens the valves fully to the heater matrix and allows that to fill.

 

And finally, when it's all sorted DON'T forget to drain some and put the antifreeze back in.....

 

Tony

unlikley but maybe the water pump fins are worn and not operating properly, or a sticky thermostat?? which would cause it to over heat and push water out?

 

Just idea's and opinions.

A couple of other points I forgot in earlier posts

 

If you still have air con then switch to max in econ mode .... this opens the valves fully to the heater matrix and allows that to fill.

 

And finally, when it's all sorted DON'T forget to drain some and put the antifreeze back in.....

 

Tony

 

As you may have guessed its well worth stating the obvious here!

 

My air con does work, but has the later analogue controls, so no econ mode. All I have is a dial for the temp and a button for air con on/off. Does work though! but i am getting warm air on demand, which didnt happen for a bit..

 

The car is due its MOT early Sep so taking it to Zed World for some TLC at the end of Aug. Is my intention to replace most of, if not all, the fluids then (diff, 'box, engine oil and rad flush). But thanks for the reminder

 

Just been for another run tonight, everything seems ok, will check levels again tomorrow. I hope it is gonna be OK, cos now the suspension is healthy the car feels awesome, I'm very impressed with the Zed - great car and seemingly, tough as old boots.

unlikley but maybe the water pump fins are worn and not operating properly, or a sticky thermostat?? which would cause it to over heat and push water out?

 

Just idea's and opinions.

 

Judging by the amount of water it threw out when I turned it over with the rad cap off (the only way I could think to check the pump) it seems to be in rude health. Had my doubts about the thermostat, but it gets the benefit of the doubt for the time being.. Seems it was just the fact it had no water and therefor nothing mechanical.

 

Thanks though

Could you simplify the above fault, is it the lack of coolant or the temp changing? air con wont effect the coolant different system.

Could you simplify the above fault, is it the lack of coolant or the temp changing? air con wont effect the coolant different system.

 

Well, foooked if I know. The reason I got onto the air-con topic was because of one of the above replies. Personally i'm ignorant to the inner workings of the Zed, although I am trying to learn..

 

Definitely not short on coolant since I topped it up on the weekend. The erratic temp readings were presumably caused by the, as then, lack of coolant and the sensor was measuring the air temp of the air circulating the engine, then occaisionally getting wet - hence the up, down, up, down.

 

Been and checked the coolant again today after last night's run and would you believe it, the water was right up underneath the rad cap. It has actually gone up since I checked it yesterday.. I can only assume this is because of ambient temperature and/or a change it atmospheric pressure?

 

Looking at the positives - it doesn't seem to be using water - yet.

 

Still can't believe I didnt cook something at the weekend though:mellow:

Econ mode on the aircon and turning up the temp to max opens all the valves to the heater matrix so you can fill it/flush it

 

I know the Aircon system itself is independent of the cooling system but it can call for heat and opens the valve to the heater matrix

 

Thats why I said it above

Econ mode on the aircon and turning up the temp to max opens all the valves to the heater matrix so you can fill it/flush it

 

I know the Aircon system itself is independent of the cooling system but it can call for heat and opens the valve to the heater matrix

 

Thats why I said it above

 

There we go, hope that clarifies the air con topic..

 

Just a shame I don't have econ mode..

There we go, hope that clarifies the air con topic..

 

Just a shame I don't have econ mode..

 

Econ mode is simply ECONOMY mode (air con off) hence better fuel economy, less engine load.

 

You do have econ mode in a sense. That is your air con OFF button. All econ mode does is keep the compressor off-line and the cold air is basically only as cold as the outside air.

 

If you were to change your coolant, all you would do when filling is make sure you air con is off (ECONomy) and turn you heat dial to max. This allows the whole system to fill properly.

Thats why the air con topic was raised.