Checking engine oil cooler for leaks

Special tools and workshop equipment required

• Refractometer - T10007-
• Hose clamps up to 25 mm - 3094-
• Cooling system tester - V.A.G 1274-
• Adapter for cooling system tester - V.A.G 1274/8-
• Pliers for spring-type clips - VAS 5024 A-
• Drip tray - V.A.G 1306- or drip tray - VAS 6208-

• Torque wrench - V.A.G 1331-

Without illustration:

• Expansion tank - 1K0 121 407 A- or expansion tank - 1J0 121 407 B-
• Sealing plugs - 191 211 343-
• Cap - 1J0 121 324-
• Coolant hose - 251 265 056-

Condition:

• Engine cold

Test sequence

• Remove noise insulation ⇒ Rep. gr. 50.
• Drain coolant ⇒ 19 – Cooling.
• Loosen hose clip on engine oil cooler with spring-type clip pliers - VAS 5024-.
• Remove engine oil cooler with housing ⇒ 3 Oil filter, oil pressure switch.

Checking when removed

• Clamp housing with old seal on a suitable, level and clean surface.
• Attach plug -2- to venting connection of expansion tank -1-.
• Secure coolant hose -3- on engine oil cooler and expansion tank.
• Fill expansion tank up to “max.” mark.
• Fit cooling system tester - V.A.G 1274- with adapter for cooling system tester - V.A.G 1274/8- on expansion tank.
• Generate about 1.6 bar pressure using hand pump of tester.
• Observe pressure drop on pressure gauge. A pressure drop within 10 minutes is not permitted.

If the pressure drops:

• Renew engine oil cooler ⇒ 3 Oil filter, oil pressure switch.

Installation is carried out in the reverse order. When installing, note the following:

• Renew seal for housing.
• Check coolant level and, if necessary, replenish ⇒ 1.3.1 Draining.
• Check engine oil level, replenish engine oil if necessary ⇒ 1.3 Removing and installing sump.