B4 still losing coolant

What would cause my car to push coolant out of the expansion tank reservoir? I have a new water pump. Would a bad thermostat cause this?

Would a coolant overfill cause this?

No. I put a towel under the reservoir. The towel was soaked with antifreeze. When it pushes it out The dash light flashes showing me it is low on fluid again. I fill it back up. It does the same thing. I though I had a line kinked but that didnt fix it. It has a new timing belt and water pump. It was doing this before the new pump also. It doesnt overheat. Its not a head gasket. I cant figure it out

When was the coolant last replaced?

Not a tstat issue. Possibly head gasket if nothing else.

Coolant was replaced when water pump and tbelt was done about 2 weeks ago. The car doesnt run hot and has never overheated but I also noticed that some of the heater lines dont get hot even after a 30min drive on the interstate. Seems like the coolant isnt circulating

Are you able to squeeze the rad hoses when it's doing this? If your getting compression in the cooling system they'll be hard. Could your EGR cooler have a leak which would allow exhaust gas to push coolant out?

The lines are firm. How would I check for a EGR cooler leak?

Air pockets, is the bottom of the radiator getting hot?

If not then fill the radiator separately while squeezing the bottom hose so all of the air will get pushed out. I like to take the hose off the head and use it as a filler tube. I typically fill the engine with coolant and the first part of the radiator with coolant with the last bit being water so if I loose any it will be water. If you continue to have problems you could drill a tiny weep hole (smaller the better) in the thermostat, this will allow air to escape.

jcrad said:

The lines are firm. How would I check for a EGR cooler leak?

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Pressure test, or maybe try to bypass it for diagnosis. You're not getting any steam/ White smoke from the tailpipe right? If WP, T-Stat, pressure cap ar all good and you're not overheating (yet) , prob headgasket. Clogged rad or air pockets would make it run hot before boiling over.

Just a follow up. Wasn't showing white smoke from exhaust, wasn't overheating. Car was running fine. It had no milky oil, and no oil in coolant, it was just pushing coolant out of the reservoir. Pressure test showed too much pressure. Ended up being a blown head gasket

That happens sometimes. It doesn't always suck into the combustion chamber (white smoke) but blowing stuff out the reservoir always makes me worry about head gaskets.