What is this piece that has been welded and blocked off on my car?
What did it attach to?
It's below the coolant temp sensor on the drivers side of the motor.

It was only fingertight and was probably what was leaking... but the housing next to it was rubbed by it and thats what the plastic shown in the other pic is.

 

Looks like hack secondary air injection blockoff plate??? Probably had exhaust gasses leaking (looks sooty), which could have melted the temp sensor housing.

You have a combivalve and/or air pump on your car?

combi = shiny thing just below the DV in this pic

 

Here's mine...

 

and these:

 

Sai block off plate



Plate installed

 

Correct sir, it was a bootleg SAI delete
( don't blame whoever did it... the plate is $35!!! )

Problem is it worked loose and the gas coming out melted through the coolant T that holds the coolant temp sensor... I couldn't believe how it ate through it.

 

i had one of the screws holding the temp sensor housing fall completely out. somehow, i didnt leak any coolant even though it was only held by one screw and it was warped way out. funny stuff you find under the hood sometimes

 

was it stripped, or just fell out?

Weird because one of mine just fell out while i was fighting to get the hoses off.

I forogot to check to make sure its not stripped... kinda worried now that im thinking about it.

 

i was under the hood one day, and just noticed i was one screw short. threads were fine, it just backed out I'd assume. Replaced it with a new screw and it was fine.

Hard part is, once those orings get a chance to grow, its real hard to fit it back in place. I ended up cutting out a 1/4 inch and supergluing the oring back together.

 

My REAL block off plate just showed up today

Its going to be a nice week, plate today, turbo tomarrow, and bushings either thur or fri