Since I've fitted the fmic I've had to fit the small supplied expansion tank. I've found that it keeps pressurising the tank and popping the top off. The car is running fine and doesn't over heat. Any ideas what's going on? The cap fits firmly so slightly unsure what to make of it all.

 

Is it sealed air tight when the top is on? The OE one can vent to atmosphere. So if for some reason this aftermarket one is sealed that will be why. Not sure why they wouldn't have catered for that tho...

 

maybe too much fluid in it? mines is usually 1/4 full when cold

 

Is it the Japspeed one? If so, it needs a small hole drilled in the top to relieve pressure.

JohnD

 

Yes it is johnd. Thanks for that. I'll give it a try.

Thanks for your help all.