Jkat

Hey all! New to the forum but I picked up a 03 a4 Quattro with 1.8t and 5 speed manual. Anyway, it was having an issue where it would spit coolant out of the reservoir until I got low on coolant warning. Well, I changed the thermostat, j plug, reservoir cap, and bled the system and it’s still not totally fixed. Now it spit coolant out until it’s below minimum in the reservoir and no more is coming out. The thing is it’s still rising all the way up to above max then sinking back down. Using an OBDeleven I saw that it happens as “engine outlet temp (actual)” peaks at 102 C then it drains back and the temp drops to 98 C. I don’t know if that means anything, just offering all the info I have. Here’s a video of it happening:


does anyone have any idea why it could be doing this? I know it’s not supposed to be... I’ve block tested it and pressure tested it and found nothing. I’m really at a loss... any help would be appreciated! Thanks!

W261w261

Let it get cool, then remove the reservoir cap, turn on the engine and let it come up to temperature. Do you see bubbles in the coolant? If so, you have a blown head gasket.

Jkat

turbo510

How's the heater working? If not hot when the reservoir is acting like this, then I would suspect the coolant pump.