1997 TJ TDI swap mystery fitting puking coolant

[ozark]

Got my TDI swap running today but it started dumping coolant when it warmed up enough to open the thermostat. I took this build over so didn't install the engine. Thought all of the coolant hoses were connected. No leaks until it warmed up. There's a 3/4" fitting in the block/head under the exhaust manifold toward the rear. Looks like something should be connected to it. It has a slot for some type of clip ? Don't know how to add a pic to post. Don't want to plug it not knowing what it's for.

Thanks for any help.

 

[Chris]

Use the "attach files" and upload a photo.

 

[ozark]

Use the "attach files" and upload a photo.

 

[Chris]

View attachment 655242

View attachment 655243

Okay, well clearly you've got something important missing there, likely an accessory or a secondary coolant line. On TDI swaps, sometimes there are additional lines for turbo coolers or heater cores, depending on the setup.

If coolant is leaking from it now that the engine is warming up, it likely means it's not capped off properly or there's supposed to be a line connected there. You're going to need to talk to the guys on the TDI forums and figure out what exactly goes there that you're missing. I don't think many people here are going to be able to help you since none of us (with the exception of maybe @RustyAutoholicGuy) know TDI engines.

You might want to check the service manual for your specific TDI engine model to see what typically connects there. I wish I could be of more help, but unfortunately this is a TJ forum and you've got a VW engine in yours!