Oil Thermostat

Oil pipe rubber oil tank to thermostat.

Fits:
Porsche 964 1989-94

*For cars with Thermostat Part Number:
96420704705
96420704307
96420704308

Diagram ref no 22

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420725103

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Oil pipe rubber oil tank to thermostat.

Fits:
Porsche 964 1989-94

*For cars with Thermostat Part Number:
96420704705
96420704707
96420704708

Diagram ref no 22

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420725103

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Oil pipe supply front cooler to thermostat.
These are long pipes running down the side of the car

Fits:
Porsche 964 1989-94 3.6L
Porsche 964 Turbo

Diagram Ref No 2

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420713304

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Oil pipe supply front cooler to thermostat.
These are long pipes running down the side of the car

Fits:
Porsche 964 1989-94 3.6L
Porsche 964 Turbo

Diagram Ref No 2

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420713304

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Oil pipe thermostat to oil filter.

Fits:
Porsche 964 C2 / C4 / RS 1989-94

This product supersedes Porsche's old part numbers:
- 96420725404
- 96420725405
- 96420725406
- 96420725407

Diagram Ref No 46

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Related, superseded, cross reference or alternative numbers for comparison.

96420725414

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Oil Pipe – Thermostat to Oil Filter 

The Porsche 964 Oil Pipe from the thermostat to the oil filter is a critical component within the engine's lubrication and oil cooling system. Designed specifically for Porsche 964 models produced between 1989 and 1994, this oil line transfers engine oil between the thermostat assembly and the oil filter housing, ensuring continuous oil circulation and filtration before oil is distributed throughout the engine.

Fits:

• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Diagram Ref No 46

The Porsche 964 relies on a sophisticated dry-sump lubrication system that not only lubricates critical engine components but also assists in engine cooling. This oil pipe plays an important role in maintaining correct oil flow, pressure, and filtration efficiency, helping to protect the engine under both normal driving and high-performance conditions.

Whether you are restoring a Porsche 964, rebuilding an engine, or repairing a leaking oil system, replacing ageing oil pipes is essential for maintaining reliability and preventing costly engine damage.

What Does This Oil Pipe Do?

The thermostat-to-oil-filter pipe forms part of the engine's oil circulation circuit.

Its primary functions include:

• Transporting oil between the thermostat and oil filter housing
• Maintaining uninterrupted oil flow through the lubrication system
• Ensuring oil passes through filtration before recirculation
• Supporting stable oil pressure throughout the engine
• Assisting the operation of the Porsche dry-sump oil system
• Helping maintain proper engine cooling and lubrication

Without a properly functioning oil pipe, oil flow can be compromised, placing the engine at risk of lubrication issues and overheating.

Why Does This Oil Pipe Fail?

The oil pipe operates in a demanding environment where it is constantly exposed to heat cycles, oil pressure, vibration, road contamination, and age-related deterioration.

Common causes of failure include:

• Corrosion of metal pipe sections
• External damage from road debris
• Fatigue from vibration and engine movement
• Deterioration of sealing surfaces
• Cracked or weakened pipe connections
• Oil contamination and sludge build-up
• Damage during previous repairs or engine removal work
• Age-related wear on original factory-installed lines

As the vehicle ages, corrosion and fatigue become increasingly common, particularly on original oil system components.

Common Symptoms of a Failing Oil Pipe

Signs that the thermostat-to-oil-filter pipe may require replacement include:

• Visible oil leaks
• Oil residue around the pipe or fittings
• Corrosion on exposed metal sections
• Reduced oil pressure
• Oil smells from the engine bay
• Damaged or crushed pipework
• Difficulty removing seized fittings during servicing

Because the oil system is vital to engine protection, even small leaks should be addressed promptly.

When Should You Replace It?

Replacement is recommended when:

• Oil leaks are present
• Corrosion becomes visible
• Pipe fittings become damaged or seized
• During engine rebuilds
• During oil thermostat replacement
• During major oil system refurbishment
• As part of preventative maintenance on ageing vehicles
• During restoration projects where long-term reliability is a priority

Replacing ageing oil lines before failure helps prevent oil loss, lubrication issues, and expensive engine repairs.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420725414

The product you are viewing cross references to these numbers

Oil Thermoptat Cap Cover.


Fits: 964 Carrera 2 / Carrera 4 1989-94

Click 'Zoom in' for large parts diagram.
Diagram Ref No 14.

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Related, superseded, cross reference or alternative numbers for comparison.

96420735101

The product you are viewing cross references to these numbers

Oil Thermostat Insert.

 


Fits:
Porsche 964 1989-94

Click 'Zoom in' for large parts diagram.
Diagram Ref No 13.

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96420734902

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Oil Thermostat O-Ring on Engine Case - 39.2 x 3mm
OE Match oil thermostat O-ring on engine case, 39.2 x 3mm, for Porsche 911, 914-6, 964, and 993 models. This replacement sealing O-ring helps prevent oil leaks at the engine-mounted thermostat area and supports correct engine oil system sealing.

Fits:
Porsche 911 - 1970 to 1989
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1997
Porsche 914-6 - 1970 to 1976

Diagram ref no 34

The O-ring seals the joint between the oil thermostat and engine case. A correctly fitted seal helps prevent oil seepage, maintain oil system integrity, and keep the engine area clean and leak-free.

Functions
• Replaces the oil thermostat O-ring
•  Seals the thermostat connection on the engine case
•  Helps prevent engine oil leaks
•  Supports correct oil system sealing
•  Suitable for oil thermostat, engine case, or oil leak repair
•  Replaces hardened, flattened, cracked, swollen, or damaged O-rings
•  OE Match replacement for Porsche engine oil system service.

Why Replace This Part?
Oil thermostat O-rings can harden, flatten, crack, swell, or lose sealing ability due to heat, age, oil exposure, and pressure cycles. A worn or damaged O-ring may allow oil seepage around the thermostat area, causing oil residue, low oil level concerns, engine bay contamination, or failed inspection. Replacement is recommended whenever the thermostat is removed or oil leakage is present.

When to Replace This Part
•  Oil is leaking around the engine-mounted thermostat area
•  The oil thermostat has been removed or serviced
•  The O-ring is hard, flattened, cracked, swollen, or damaged
•  Engine case sealing work is being carried out
•  Oil seepage or oil residue is visible around the thermostat connection
•  Preventative replacement is required during engine service

Where it fits on the car
This O-ring fits at the oil thermostat connection on the engine case. It forms part of the engine oil sealing system on Porsche 911, 914, 964, and 993 models.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99970731440

The product you are viewing cross references to these numbers

Oil thermostat. Fits to oil lines.



Fits:
Porsche 964 1989-94

Please note: For early models with the early type thermostat you will also need:
96420724107 - Oil hose for thermostat
96420725103 - Oil pipe rubber (oil tank to thermostat)


Click 'Zoom in' for large parts diagram.
Diagram Ref No 11.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420704708

The product you are viewing cross references to these numbers

Oil thermostat. Fits to oil lines.



Fits:
Porsche 964 1989-94

Please note: For early models with the early type thermostat you will also need:
96420724107 - Oil hose for thermostat
96420725103 - Oil pipe rubber (oil tank to thermostat)

Click 'Zoom in' for large parts diagram.
Diagram Ref No 11.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

96420704708

The product you are viewing cross references to these numbers

Regulator Insert O-Ring.



Fits:
Porsche 964 1990-94
Porsche 993 1994-97

Click picture for large parts diagram.
Diagram Ref No 9.