So I decided to replace my thermostat because my car wouldn't get up to operating temperature. It drove fine and everything but I felt like for a $10 oem part it was worth it to replace. I had read all over the place that the thermostat is common to go. The job was easy. I got everything all bolted back up and I started to add the coolant.

It dripped a little from the thermostat which that's fine easy fix just needs to be tightened most likely. The part that I can't figure out is when I started to fill up the coolant it started leaking from some connector that goes into a metal pan like thing under the car. It's near the thermostat just lower and more in the center. I'm not sure what the sensor or pan is but it's really the only silver pan thing with a connector going into it. It was coming out in a constant stream not very fast but it wasn't a drip drip. I didn't even touch this part so I'm not sure what is causing this. All the bolts around it are very tight.

What is this part and what can I do. Right now I have no coolant in the car as it all drained out.

 

This is what I'm talking about. That's the oil pan correct? Maybe it just looked like it was coming from that connection. Had to because it wouldnt be possible for coolant to come out Of that. I will have to look tomorrow to see where it was coming from. Didn't look like it was really coming from the housing though.

 

More details about which engine you're dealing with are needed.

Yes, the aluminum part in the picture is the oil pan. No coolant from there. A leak above is dripping down the block to the oil pan.

 

He's got an ATW.

OP, there are only so many places coolant can come from. Check the tank for cracks, check the two coolant hoses that connect to the oil cooler beneath the reservoir, and check the coolant flange at the back of the head.

 

Oil pan and that's the oil pressure sending unit attached to it. You have the 1.8 engine it looks like. I'm going to say it's probably your rear coolant flange leaking down and around your oil pan (where the t-stat goes)....on a second thought, did you REMOVE the OLD O RING and put a NEW O RING in with the NEW thermostat? It should have come with one.

 

How the F&%# can you tell that from a crappy pic of the oil pan? You must be some sort of Jedi...

 

Good point. When replacing the t-stat the gasket and t-stat housing should also be replaced. It is not uncommon for the housing to warp and not seal again once removed.

Haha, I wish. In his other thread he was asking questions about 1.8Ts, plus below his name he has his year listed as 2000 = ATW.

 

Okay. Less Jedi and more Sherlock Holmes...

Haven't heard from you in a while. How's it going?

 

Your use of double spaces disturbs me.

Things are better than the last time we talked. Still looking for work, but at least my car is running. Got a cracked SMIC that is hopefully the cause of my lost boost, picked up a full set of cloth sport seats for $75 at the PnP. Gotta get it smogged in a few months so I'll be putting the stock cat back in.

Sorry for the thread jack OP.

 

I don't think it would be any of those as it was perfectly fine today and just started when I changed the thermostat. I only touched the thermostat today so my guess is that it is leaking from there, it has to be I would be surprised if it wasn't. I'm just very shocked that I didn't notice that it was coming from there because it sure looked like it was coming from the oil pan, when of course thats not the case. It was just one of those moments I guess.

Yes 1.8. Does the thermostat housing sit on the rear coolant flange? I'm not sure why all of a sudden something I didn't touch would just start leaking.

Yes I did remove the old O Ring and put in a brand new one that came with the OEM thermostat. I could be possible that the O Ring didn't line up well enough. The first thing Im going to do it remove the thermostat and make sure the O Ring is seated correctly.

Now when I put the new thermostat into the housing it didn't stay in place. However to get the old tstat out it took me about 5-10 minutes of pulling and twisting. Is this just because it was it there for a long time?