Ryan'sAudiA4

I don't have that pan under my engine anymore. And where is this coolant pipe on top of the engine that you speak of? And I guess if it leaks when engine is warm and hoses can split when its warm I guess that makes sense that there could be a leak when stopped and idling. And how do I tell if the coolant out of the heater core is warm? Do I have to move the hose to reveal the small bleeder hole?

jseklund

Here is a video on the coolant temperature sensor replacement - it is located between the head and the firewall and down a little.


It sits in a hole on the top of the pipe...look carefully for white crud around it - there is an O-Ring seal that goes in there that fails over time and you will see coolant puddle on the top of the sensor in the hole it presses into, or white crud on the pipe.

If you pull the plastic piece near your windshield you will see the two hoses that go to your heater core - it sounds like you already have an idea about these. One has the bleeder hole - both of the hoses should be warm once the engine is up to temperature and the heat is on - you can just touch them but be careful! Once the car is up to temp, the coolant is red hot and so are all of the coolant pipes.

Also, if you have to replace the green sensor - do it when the engine is cool to avoid fluid shooting out at you in geyser fashion.

Ryan'sAudiA4

Your talking about the coolant flange right? And when I get home ill check to see if the pipes are warm. If there warm, what does that mean?

Ryan'sAudiA4

what do you mean by steam jets?

jseklund

If they are both warm, it is an indicator that coolant is traveling through the engine, to the heater core, and then back out of the heater core....which indicates the system has fluid throughout and is working properly....but the boiling suggests the system is not pressurized....so if it is working properly otherwise (hot coming out of the heater core), I would assume you have a leak that keeps it from pressurizing.

Ryan'sAudiA4

Well drove it, got it to half. Got out, both hoses were hot, but I noticed pink coolant on the other side of my battery and I started to dig. And then over by my right strut, I also a black wire cover with pink coolant on it. So I removed the black thing that covers the heater wires and the inside of it was covered in coolant, and when I looked down it was wet looking so I think my heater core hose is leaking. Here's a picture.

Ryan'sAudiA4

Say something about this photo

jseklund

It's been a while since I looked at the A4 heater hoses - make sure the hoses are pushed on all the way, that the hose clamps are secured, etc.

If you get it up to temp and then put it in park and have someone throttle the engine to about 2-3K RPM, you may notice it starts spraying out. Hopefully it is one of the hoses and not the core, which is labor intensive to replace.