Hose. Porsche 944 1985–91 › 95111051100

Hose.
The Porsche Hose is a replacement air hose for the turbocharger bypass and intake air control system fitted to selected Porsche 944 Turbo (951) models.

Fits:

• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988

The Porsche 944 Turbo uses a forced-induction system in which the turbocharger compresses intake air to improve engine performance.

To maintain stable operation, the intake system incorporates a bypass valve that helps manage pressure when the throttle is closed, particularly after acceleration.

The 95111051100 hose forms part of the plumbing associated with this valve.

Its flexible construction accommodates the connection between adjoining components while helping maintain the intended air seal.

A secure connection is important because leaks within the turbocharger intake and recirculation system can interfere with pressure management and engine operation.

Over time, the original hose may become hard, brittle or cracked due to age, heat, oil vapour and repeated thermal cycling.

The hose ends may also deteriorate around their clamps, allowing air to escape or enter through an unintended path.

Damage can be difficult to identify because small cracks may form on the underside of the hose or become more apparent only when it is flexed.

A defective hose may contribute to unstable idle, reduced boost response, inconsistent engine performance or unusual air-leak noises, depending on the location and severity of the leak.

Replacing a worn hose helps restore a properly sealed connection within the turbocharger bypass system.

This component is particularly relevant to maintenance and restoration of the Porsche 944 Turbo, where original rubber intake hoses may have deteriorated after several decades of use.

Suitable for repairs to the turbocharger bypass valve plumbing, diagnosis of intake air leaks and refurbishment of the original engine intake arrangement.

What This Product Does:
The hose connects the turbocharger bypass/shut-off valve to its associated rigid intake pipework.

The bypass valve is used to manage pressure within the turbocharged intake system when operating conditions change.

During acceleration, the turbocharger supplies compressed air to the engine.

When the driver releases the accelerator and the throttle closes, pressure conditions within the intake system change rapidly.

The bypass valve provides a controlled route for air recirculation, helping reduce compressor surge and maintain stable turbocharger operation.

The 95111051100 hose provides one of the sealed connections required for this arrangement.

Its main functions include:

• Connecting the bypass valve: Links the turbocharger cut-off valve to the corresponding rigid pipework.
• Maintaining an airtight connection: Helps prevent unintended air leakage within the intake system.
• Supporting pressure recirculation: Allows the bypass valve plumbing to operate as designed.
• Supporting turbocharger response: Helps maintain proper pressure management when the throttle position changes.
• Accommodating movement: Provides a flexible connection between adjoining intake components.
• Maintaining intake integrity: Helps preserve the original arrangement of hoses, valves and connecting pipes.
• Reducing unwanted air leaks: Maintains the intended sealed path when correctly installed.
• Supporting stable engine operation: Helps avoid symptoms associated with defective intake plumbing.
• Maintaining original vehicle configuration: Provides a replacement for the relevant Porsche 944 Turbo connection.

Ageing rubber can harden, lose flexibility or develop cracks.

Common symptoms of a worn or damaged hose include:

• Visible cracking: Small splits may develop along the hose body or around its ends.
• Hardened rubber: The original material may become stiff and less able to seal.
• Brittle hose ends: The hose may crack when disturbed during servicing.
• Loose connections: Deteriorated material may no longer seal securely beneath the clamps.
• Air leakage: Cracks or loose joints can allow unintended airflow.
• Hissing noises: A leak may produce an audible air sound during operation.
• Inconsistent boost response: Leakage within the intake control system may affect pressure behaviour.
• Reduced engine performance: A significant leak may contribute to poor engine response.
• Unstable idle: Certain intake air leaks can disturb idle quality.
• Hesitation during acceleration: Incorrect airflow or pressure management may contribute to hesitation.
• Rough engine running: Air leaks may affect the intended air and fuel mixture.
• Poor throttle response: A compromised intake seal may contribute to delayed or inconsistent response.
• Oil contamination: Oil vapour deposits may accelerate rubber deterioration.
• Swollen or softened rubber: Exposure to oil and heat may affect the hose material.
• Damaged retaining clamps: Loose or corroded clamps can prevent secure attachment.
• Hose displacement: An incorrectly secured hose may move away from its connection.
• Previous temporary repairs: Tape or unsuitable substitute tubing may indicate a deteriorated original hose.

1. Restore an Airtight Connection

A cracked or hardened hose may allow air leakage at the bypass valve connection.

A correctly fitted replacement restores the required seal.

2. Support Proper Turbocharger Pressure Management

The bypass valve relies on intact connecting hoses to operate as intended.

Replacing a damaged hose helps maintain the proper recirculation arrangement.

3. Address Intake Air Leaks

Unintended air movement within the intake system can affect engine operation.

A replacement hose helps eliminate one possible source of leakage.

4. Improve Consistency of Engine Operation

Where a defective hose is responsible for an air leak, replacement may help restore smoother running and more consistent response.

It will not correct unrelated engine-management or turbocharger faults.

5. Replace Ageing Rubber

The original Porsche 944 Turbo hose may have been exposed to decades of high temperatures and engine vibration.

Even if no major leak is visible, rubber that has become brittle or cracked should be renewed.

6. Reduce the Risk of Hose Disconnection

Damaged hose ends can lose their grip on adjoining pipework.

Replacing the hose and ensuring correct clamp tension helps maintain secure attachment.

7. Support Classic Porsche Restoration

A correctly specified hose helps restore the original intake plumbing during engine-bay refurbishment.

8. Complement Bypass Valve Servicing

When repairing or replacing the turbocharger shut-off valve, it is sensible to inspect the adjoining hose and clamps.

Replacing a deteriorated hose during the same repair may reduce the need for further dismantling.

9. Prevent Further Deterioration

Small cracks can increase as the hose is exposed to additional heat and movement.

Replacement before complete failure helps maintain the integrity of the system.