OVERVIEW
Original pressure-relief valve for the specified cylinder head
078-103-363-P is the Genuine VW/Audi pressure-relief valve listed in the original cylinder-head assembly for the confirmed application below. Its threaded body and valve configuration must match the assigned engine position.
Pressure-control components must be selected by their original specification. Replacing this valve is appropriate when the engine repair procedure and diagnosis identify it as defective or when its body is damaged; it should not be chosen solely by thread size or external appearance.
Technical details
- Complete factory number: 078-103-363-P.
- Factory specification: factory cylinder-head pressure-relief valve, revision P.
- Design: threaded metal valve body with external drive and central passage, as pictured.
- Quantity supplied: one individual pressure-relief valve.
One individual valve is supplied. Cylinder head, sealing components, engine oil and other valves are separate. This listing does not supply a complete cylinder-head repair kit or a general-purpose plug.
Common reasons to replace
- The engine-specific test procedure identifies a valve fault.
- The original valve body, threads or drive are damaged.
- The valve is missing from its assigned original position.
- The applicable cylinder-head repair procedure requires replacement.
Follow the engine-specific diagnostic procedure and inspect the valve bore and adjoining oil passages as required. Pressure symptoms can have several causes; a new valve cannot repair worn bearings, blocked passages or damaged engine castings.
Vehicle fitment
Use only at the original cylinder-head valve position specifying this complete number. Confirm the engine, original valve and serviced assembly before ordering.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi 100 quattro | 1993 | 2.8L gasoline V6 | C4 quattro sedan or Avant; matching original cylinder head | Assigned cylinder-head pressure-relief valve position; match original complete valve number and engine assembly. |
Installation guidance
Follow the cylinder-head repair procedure, maintain cleanliness around open oil passages and use the specified sealing and tightening method. Do not apply an arbitrary sealant or substitute a plain threaded plug.
Complete the prescribed engine checks and inspect the serviced joint for leakage. Verify any required pressure readings using the engine-specific test procedure.
Ordering information
One individual Genuine VW/Audi pressure-relief valve. Cylinder head, oil and separately required sealing parts are separate. Confirm original number and installation position.