MLS head gasket PSA 1.6 16V TU5J4 TU5JP4

The Peugeot and Citroën engines covered

The TU5J4 and TU5JP4 are the 1.6 litre (1587 cc) 16-valve petrol inline fours of the PSA group. They power the Peugeot 106 S16, 206, 207, 307, 308, 1007, Partner and Hoggar and the Citroën Saxo, C2, C3, C4, Xsara and Berlingo in the table below. One cylinder head covers all four cylinders: the gasket is sold individually, one per engine.

The original gasket carries part numbers 0209.W8 and 0209.F7. The manufacturer publishes neither its bore, nor its thickness, nor its construction. It is calculated for standard combustion pressure: as the pressure climbs, the clamping load weakens, the head lifts and coolant reaches a cylinder.

Reinforced cylinder head gaskets

The seal does not depend on the gasket alone: the fasteners that clamp the head to the block count just as much. A composite gasket settles permanently beyond 100 N/mm², whereas the 301 stainless steel of the MLS withstands 517 N/mm², five times more, and regains its shape at every combustion. With the O-Ring, the stainless ring isolates the combustion chamber by itself and the gasket body closes the water and oil circuits, with no machining of the block.

This page collects the part numbers of two racing manufacturers, Athena and Cometic, in three constructions: the stainless-ring O-Ring and the multi-layer MLS from Athena, the multi-layer MLS from Cometic. The gasket bores are 76 to 81 mm and the thicknesses run from 0.69 to 3.56 mm, enough to set the compression ratio without touching pistons or head. As a rule, the gasket bore chosen is at least 0.5 mm larger than the actual cylinder bore. Each part number is sold individually, one gasket per engine.

Technical specifications

A gasket's volume is the space it leaves free above each cylinder: it adds to the combustion chamber and lowers the compression ratio by the same amount. Use it only to compare gaskets of the same bore.

Preparation and fitting

Before assembly, run a straight edge over the head and the block to check their flatness, and have whichever needs it machined flat. No sealant: Athena and Cometic supply their gaskets already coated.

Technical guide

The three constructions offered

	O-Ring / Cut Ring Athena A steel body lined with asbestos-free aramid, with a stainless steel compression ring crimped around each cylinder. The ring concentrates the clamping force on a narrow band, where the seal is made, while a silicone bead closes the water and oil passages. It is the construction that best withstands high combustion pressures in the range.
	Athena MLS Two to five AISI 301 stainless steel sheets, laser cut, stamped, then riveted. A folded sheet, the Gas Stopper, surrounds each cylinder and carries the clamping force toward the combustion chamber; embossed beads isolate the water and oil circuits. The outer faces are coated: one coat withstands heat and fills small flaws in the block and head, a silicone coat stops the gasket sticking at removal. It is Athena's all-steel solution, from the tuned naturally aspirated engine to moderate boost; beyond that, the O-Ring remains the construction that takes the highest pressures.
	Cometic MLS Stamped stainless steel sheets, stacked and joined by rivets. The outer sheets carry active beads around each cylinder and each fluid passage, and the seal is achieved with a measured clamping load and little bore distortion. A versatile choice, from the tuned naturally aspirated engine to reasonable boost.

Choosing bore and thickness

Gasket bore. The Cometic MLS comes in 76, 76.5, 79, 80, 80.5 and 81 mm (79 mm for the C4493), the Athena O-Ring in 80.5 mm and the Athena MLS in 80 mm.

Thickness. Peugeot does not publish the thickness of the original gasket. A thicker gasket enlarges the combustion chamber and lowers the compression ratio; a thinner one reduces it and raises the ratio.

As the original thickness is not published, measure with a dial gauge the height by which the pistons protrude above the block deck: it gives the clearance left between piston and head, especially with the thinnest thickness.

The two brands

	Athena S.p.A. is an Italian gasket and engine parts company whose head office and main plant are in Alonte, in Veneto, with other sites in Spain, the United States, Brazil and India. Its multi-layer gaskets are fitted as original equipment by car makers, and its racing range is entirely designed and made in Italy.
	Cometic Gasket, Inc. is an American maker of engine gaskets and sealing solutions, born in 1989 in Concord, Ohio. Its speciality: the made-to-measure gasket, at the bore and thickness required, made entirely in the United States from American materials.

Advantages over the original gasket

When a reinforced gasket becomes necessary

• Adding forced induction, or raising boost on an already turbocharged engine
• Cylinder rebored beyond what the bore of the gaskets offered (76 to 81 mm) covers
• Looking for a compression ratio different from standard, higher or lower
• Engine that has already lost its gasket, or is consuming coolant
• Competition use, where the gasket goes through repeated temperature rises

Vehicle compatibility

OEM part number: 0209.W8 and 0209.F7.

Important: the gaskets on this page are listed for the TU5J4 and TU5JP4 1.6 litre engines of the survey below, at Peugeot and Citroën. For any other vehicle, check the engine code first before ordering.

Why switch to a reinforced gasket?

When the original gasket reaches the end of its capacity, the reinforced gasket takes over: under a higher combustion pressure, it keeps its shape instead of collapsing.

As soon as an engine gets a turbo, a supercharger or a raised compression ratio, the head gasket is the first link to give way. A reinforced gasket avoids the leak and the cylinder head removal that follows, a job far more expensive than the part.