Morning all. Not sure if anyone can help but I have a strange cooling fault after fitting a low temp thermostat to my 2003 C4S.
The car will get up to the new slightly lower temp OK (just under the 80c mark) and when driven gently at slow or motorway speeds the needle will remain fairly steady, even at 70 mph for a long period.
The problem I have is when the car is driven hard and RPM is above 4k and beyond the coolant temp will rapidly drop. When you bring the RPM back down but still maintain the same speed it will quickly climb back to normal temp.
So I'm thinking faulty thermostat or more likely an air lock in the system. I've done around 400 miles since fitting it and the coolant level has not moved since originally bleeding the system.
For info the LT thermostat is a design 911 one and I fitted a new -4 expansion tank cap at the same time. Car was running perfectly before fitting the new thermostat.
If I have got an air lock. Best advice to remove it?
Thanks in advance,
Phil.
The car will get up to the new slightly lower temp OK (just under the 80c mark) and when driven gently at slow or motorway speeds the needle will remain fairly steady, even at 70 mph for a long period.
The problem I have is when the car is driven hard and RPM is above 4k and beyond the coolant temp will rapidly drop. When you bring the RPM back down but still maintain the same speed it will quickly climb back to normal temp.
So I'm thinking faulty thermostat or more likely an air lock in the system. I've done around 400 miles since fitting it and the coolant level has not moved since originally bleeding the system.
For info the LT thermostat is a design 911 one and I fitted a new -4 expansion tank cap at the same time. Car was running perfectly before fitting the new thermostat.
If I have got an air lock. Best advice to remove it?
Thanks in advance,
Phil.