Help Please

hawkeysr

Dedicated Member
Joined
Nov 2, 2020
Points
28
Hi all

I have been having a strange issue for a while where on a long drive the temp gauge will drop from the middle down to cool and then slowly back up again and repeat, doesn’t do it all the time just occasionally. So with this in mind I decided todrain the coolant and replace the thermostat (eurocar parts jobbie). I never have any loss of heater function in the car when this happens?!?

So new thermostat fitted, coolant filled and then more problems started. I filled the coolant with the heat on hot and setting 1 as advised and the car heated up to the middle and had not hot heat inside the car.. took it for a long drive came home and pulled up in the drive stopped the engine and I could hear water splashing 😳.

Opened the bonnet and coolant was blowing out of the cap, well the underside of it. I unscrewed the valve and let the air out ... well steam and the coolant leak stopped.

let the car cool down and topped it back up, ran the engine to get any air out and took it in a drive.

came home and same thing, coolant leaking?

Any ideas... I’m starting to think the thermostat is faulty as when you to temp with the bleed valve removed nothing came out? I ran it for about 45 mins and all that came out was steam?

your wise advice much appreciated!?!
 

t-tony

The Legend
Deceased
Supporter
#ZedShed
Joined
Dec 31, 2013
Points
226
Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
Sounds as though you still have some air in the system. It can be a real pain to bleed these cars sometimes. Have you tried raising the front of the car?

Tony.
 

hawkeysr

Dedicated Member
Joined
Nov 2, 2020
Points
28
Sounds as though you still have some air in the system. It can be a real pain to bleed these cars sometimes. Have you tried raising the front of the car?

Tony.
Hi Tony

I haven’t my drive in on a bit of a slope so I was thinking that might be enough.. perhaps not.

I have given up for the day... but next time I will jack the front of the car right up.

what’s the best way to get the air out? Run it with the cap / bleed screw out ? Should the coolant be level with the top of the expansion tank?

many thanks
 

Fender2004

Zorg Guru (II)
Supporter
British Zeds
Joined
Sep 23, 2014
Points
105
Location
Durham
Model of Z
Z3 2.8
When I do mine I disconnect the top hose from the radiator then turn it 90 degrees, and slowly pour fluid in the hose till full. Then I top up the radiator where the top hose was connected to until full. Then reconnect the top hose to the radiator, and you should be good to go.
This has worked every time I’ve changed the anti-freeze or changed the water pump etc.
 

t-tony

The Legend
Deceased
Supporter
#ZedShed
Joined
Dec 31, 2013
Points
226
Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
I always run the engine with the filler cap off till the t/stat opens (when the level should fall) top up and replace cap. Run till radiator gets hot. Heater on hot and fan on.

Tony.
 
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