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MAHLE Piston Ring Set - 503 99 N0
MAHLE Piston Ring Set - 503 99 N0
MAHLE Piston Ring Set - 503 99 N0
MAHLE Piston Ring Set - 503 99 N0
MAHLE Piston Ring Set - 503 99 N0
MAHLE Piston Ring Set - 503 99 N0

Mahle Piston Ring Set 503 99 N0

MAHLE
Availability:
Out of stock
SKU 503 99 N0
Sold out
$28.78 - $28.78
$28.78
$28.78 - $28.78
$28.78
CALIFORNIA WARNING

Handling passenger or off-highway motor vehicle parts can expose you to chemicals such as phthalates and lead, which can cause cancer and reproductive harm. To minimize exposure, service the vehicle in a well-ventilated area, wear gloves, and wash your hands. For more information see www.P65Warnings.ca.gov/motor-vehicle-parts.

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MAHLE

Piston Ring Set

This product also goes by these part numbers: 50399N0, 503 99 N0, 964 103 925 00, 96410392500, PCG 503 99N 0, PCG50399N0

This part also goes by the following cross reference.

Cross Reference Part Number: 50399N0, 96410392500, PCG50399N0

Fits These Vehicles 9 applications
911
Make Model Engine Years
PORSCHE 911 (964) 3.6 Carrera 4 1988–1993
PORSCHE 911 (964) 3.6 Carrera 1989–1993
PORSCHE 911 (964) 3.6 Carrera RS 1991–1993
PORSCHE 911 (964) 3.6 Turbo 1993–1993
PORSCHE 911 Convertible (964) 3.6 Carrera 4 1989–1994
PORSCHE 911 Convertible (964) 3.6 Carrera 1989–1994
PORSCHE 911 Speedster (964) 3.6 Carrera 1992–1994
PORSCHE 911 Targa (964) 3.6 Carrera 1988–1993
PORSCHE 911 Targa (964) 3.6 Carrera 4 1988–1993

Fitment data last updated: 2026-05-15

Fits 9 vehicle applications Check vehicle fitment before ordering View fitment

About these Piston Rings

The MAHLE 503 99 N0 piston rings seal the gap between the piston and the cylinder wall, holding combustion pressure and controlling oil. Worn rings lead to low compression, oil consumption and blow-by.

Frequently asked questions

What do piston rings do?

The top rings seal combustion pressure, and the oil control ring scrapes excess oil from the cylinder wall back into the crankcase. Together they keep compression up and oil out of the combustion chamber.

What are the signs of worn piston rings?

High oil consumption, blue smoke especially under acceleration, low compression or failed leak-down test, loss of power, and excessive crankcase pressure.

What should I check before fitting new rings?

Measure the cylinder bore for wear and taper, and hone or machine it as required so the new rings can seat. Check the ring end gap in the bore and the fit in the piston grooves against specification.

Can I install piston rings myself?

It is a precision job that requires engine disassembly, careful measurement, correct ring orientation and a ring compressor for installation. It is best done by an experienced engine builder.

How do I make sure this piston ring set fits my car?

Compare the part numbers listed on this page with the number on your old part or in your vehicle's parts catalog, and check the fitment information. If you are unsure, contact us with your VIN before ordering.

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