Hey there,
Posting again :-( Long post.....
Have a weird problem where the coolant comes out of the expansion tank when the car gets really hot (not overheated, just say maintaining 100mph+ (runway) or sat in traffic for ages). I don't understand why it is doing it when it isn't getting hot enough to boil.
One thing - when I got a new expansion cap from renault it was white with a kind of brown centre bit. Looking at engine bay pics on here, everyone has a black one. Is the white one rated to a lower pressure? Also, if I pop the bonnet after driving for a while it is making a hissing noise, only very quietly.
Also, the system somehow gets air in it. So I bled it properly as stated in the guide, and it is fine for a few weeks, then I get the thing where the thermostat isn't opening because there is too much air by the thermostat. I open the cap when it is hot (i.e. when I notice the temp gauge is too high) and it gurgles and bubbles, loads of air goes up the top pipe to the expansion tank, the coolant goes down to replace the air and then it is fine again for weeks.
I have also noticed I have the tiniest coolant leak (only seen coolant there once) down by the bottom right (from front of car) of the radiator. I wonder whether this is letting the coolant out slowly, and then sucking air back in when the car cools down? Still doesn't explain why it gets forced out the expansion tank - it is that which most worries me.
Thanks in advance for your help! And for reading such a long post! I have springs, brake discs and pads and a throttle body sat in the corner of the living room waiting for me to fit! Do I need to add a load of other stuff to the pile???
Posting again :-( Long post.....
Have a weird problem where the coolant comes out of the expansion tank when the car gets really hot (not overheated, just say maintaining 100mph+ (runway) or sat in traffic for ages). I don't understand why it is doing it when it isn't getting hot enough to boil.
One thing - when I got a new expansion cap from renault it was white with a kind of brown centre bit. Looking at engine bay pics on here, everyone has a black one. Is the white one rated to a lower pressure? Also, if I pop the bonnet after driving for a while it is making a hissing noise, only very quietly.
Also, the system somehow gets air in it. So I bled it properly as stated in the guide, and it is fine for a few weeks, then I get the thing where the thermostat isn't opening because there is too much air by the thermostat. I open the cap when it is hot (i.e. when I notice the temp gauge is too high) and it gurgles and bubbles, loads of air goes up the top pipe to the expansion tank, the coolant goes down to replace the air and then it is fine again for weeks.
I have also noticed I have the tiniest coolant leak (only seen coolant there once) down by the bottom right (from front of car) of the radiator. I wonder whether this is letting the coolant out slowly, and then sucking air back in when the car cools down? Still doesn't explain why it gets forced out the expansion tank - it is that which most worries me.
Thanks in advance for your help! And for reading such a long post! I have springs, brake discs and pads and a throttle body sat in the corner of the living room waiting for me to fit! Do I need to add a load of other stuff to the pile???
