i'm working on putting a S4 engine into my S3 and was wondering where the small coolant nipple coming off the back of the water pump goes to? can i block it off? if so, what should i use to block off the unnecessary coolant passages?

thanks for the help.

 

block it off....Help section in AutoZone or Pepboys has rubber caps you can use...Attach a small clamp too..

 

In stock form it goes up to the TB. There is a coolant nipple on the rear iron that goes up to the TB, then another line comes down to return it to the water pump. Personally, I looped the rear iron nipple and water pump nipple together to keep the flow.

 

What dDuB said. There's another coolant nipple on the rear iron. Get a standard 90 degree coolant hose from your local parts store, and cut it to fit so the nipple on the rear iron connects to the nipple on the back of the water pump.

-=Russ=-

 

doesn't it go to the BAC on the intake manifold?

 

what diameter line should i be using? thanks fellas.

 

With the stock setup, yes.

As for the coolant line size, measure the nipple? I just went to a parts store, found a 90 degree bend of the smallest size they had, and it fit.

-=Russ=-

 

well that would be easy wouldn't it? if i can determine the size by asking here, i save myself a trip to my car before i hit the parts store

 

3/8" maybe? I can't remember precisely, but that should be close and a hose clamp will be able to tighten it down fully.

 

right on. thanks.

how much should i expect to pay for the cap that goes on the water pump neck?

 

Is your overflow on the neck or radiator, cuz that will determine if you need a pressure cap or just normal flat one.

 

i'm using the radiator from the '84, so it's on the radiator.

 

Alright, then you just need a flat one, no pressure, those are fairly cheap I think, but can't remember the price.

Wow, from mazdatrix it's like 18 bucks, weird. Mazda prices suck.

 

is there a special name for the part? i want to price-shop autozone, schucks, and napa.

 

Radiator cap (flat cap).

This is the info from Mazdatrix.

RADIATOR CAP 86-95 FLAT 15-2050-KF01 $18.67