Missing Hose?

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Yesterday | 01:51 PM

CasperVette

Thread Starter

5th Gear

Joined: Jun 2025

Posts: 5

Likes: 0

Missing Hose?

Was replacing my IAC today and found a missing hose/line? Was wondering which hose this is, what it’s for, and how to replace it. pictures attached for location. Any help is appreciated.

Yesterday | 02:29 PM

2011KLR

Drifting

Joined: Sep 2022

Posts: 1,475

Likes: 393

From: Liberty, SC

2023 C4 of the Year Finalist - Unmodified

It is a common bypass of coolant through the TB. Unless you're trying to go back to 100% stock, just leave it as it is.

Yesterday | 02:36 PM

Steve Swan

1994 LT1 1996 LT4

Joined: Sep 2024

Posts: 771

Likes: 729

From: East Front Range Colorado

i believe that is the throttle body coolant pipe on passenger side of the throttle body. you should also be able to see a same pipe on driver side, i just did this bypass on my '94 auto a couple weeks ago. if you want to learn more, type in "throttle body coolant bypass."

Last edited by Steve Swan; Yesterday at 02:42 PM.

Yesterday | 02:40 PM

CasperVette

Thread Starter

5th Gear

Joined: Jun 2025

Posts: 5

Likes: 0

Thanks a lot. good to know that it’s intentional from previous owner.

Yesterday | 09:52 PM

81c3

Le Mans Master

Joined: Dec 2005

Posts: 8,575

Likes: 961

From: Communist Colorado

Quote:

Originally Posted by CasperVette

Thanks a lot. good to know that it’s intentional from previous owner.

The bypass was made with that section of copper tubing.

Today | 03:48 AM

Gary TCB

Heel & Toe

Joined: Apr 2026

Posts: 18

Likes: 3

You can tidy up and finish the throttle body coolant bypass, presumably done by a previous owner, by fitting an appropriately sized plug or blanking cap.

Last edited by Gary TCB; Today at 03:51 AM. Reason: more info