moloveshisaudi1254

My coolant expansion tank releases coolant from the pressure release valve on the bottom of the expansion tank towards the rear of the car when the car is at operating temperature. The coolant level then falls significantly below minimum line. Is it just a faulty cap or something big?

My only other thought is that the return hose going from the oil cooler to the lines near the radiator might be having flow issues because it makes a sharp turn and looks a bit kinked. That might cause excessive pressure in the system. I did recently replace the oil cooler and flush the system.

By the way what is the capacity of the cooling system I only poured in 4L of 50/50 G11 + distilled water to get it up to min line. Seems like it should take more.

4Driver4

How does the temp gauge look? Bad t-stat?

moloveshisaudi1254

Temp gauge looks fine after a short drive, the needle sits right on the middle hash mark. The oil temp runs just a tiny bit higher than it used to. The oil temp needle sits right on the third hash mark after the 60, before it used to sit on the second mark after the 60. I haven't really taken the car for a spirited drive yet for fear of getting stranded with an overheated engine. 2-3 mile sprints down to the local stores and back, haven't caused the temp gauge needle to go over the center mark, but the coolant tank was nearly empty on the way back and steam was coming from under the hood.

Yesterday when I opened the cap to add more coolant the rubber stop in the center was stuck inside the coolant tank had to pry it out with a screw driver. The broken cap could cause a loss of pressure but that would make coolant flow out from the top of the bottle where the cap is not the bottom?

Any ideas?

Kris Hansen

Without the cap, the pressure from the system would push the coolant out. Replace the cap, I bet you'll be fine.

600whpA4

Cap since its just a pressure valve and is no longer sealing.

moloveshisaudi1254

Picked up a new cap from the stealership this evening for $20. Had no other option since I was in a hurry. So far no overflowing but coolant is still dripping slowly from the bottom. It might have to do with a really small pin-sized hole on the top of the coolant tank. It makes a whistling noise after the engine is warmed up. Tonight I will put the bumper back on since the under body work is done and take the car for a spirited drive and report back. Thanks for all the help so far guys.

P.S. Why is there a ad for DePaul University in Chicago at the bottom of the page? What does that have anything to do with anything on this website? They don't even have Mech. Engineering or any related major.

600whpA4

If the tank pressure got too high causing the cap seal to pop then the tank most likely cracked at the same time.

jimrobertson

I had same problem on same car. The expansion tank has aa pressure release on the botttom.When it is old it will **** out fluid after a good drive at normal operating temp. I started with the cap but it did not change. I replaced the tank and that fixed it.
There are lots of aftermarket tanks around.