Should I replace my engine cylinder head gasket?

The ventilation heating lines with coolant are sometimes disconnected during AC repair.

What you need to know:

  • Hello Paul, I drive a Nissan Navara, which has had overheating issues since the AC system was tampered with. I have changed the engine belts, nozzles, injector pump and bought a new engine three months ago. I even upgraded the gear box from a 5-speed to the 6-speed but the problem persists. Now, the same mechanics suspect damage to the cylinder head gasket.

Hello Paul, I drive a Nissan Navara, which has had overheating issues since the AC system was tampered with. I have changed the engine belts, nozzles, injector pump and bought a new engine three months ago. I even upgraded the gear box from a 5-speed to the 6-speed but the problem persists. Now, the same mechanics suspect damage to the cylinder head gasket. What can I do? James

Hello James, there are a couple of other component failures or factors that can cause a car engine to overheat besides a damaged cylinder head gasket. I would start by checking those components connected to the air conditioning or ventilation system. The ventilation heating lines with coolant are sometimes disconnected during AC repair, especially under the
dashboard. This could introduce a vacuum in the system. Your AC technician needs to work with a mechanic to bleed or prime the cooling system in order to evacuate any vacuum in the lines. This can be done by turning on the ventilation heater and running the fan at speed 2, for six to 10 minutes.

Thereafter, the technician should confirm that the radiator and coolant reservoir are clean with no signs of corrosion or mixture of coolant and oil (a symptom of damaged cylinder head gasket). The working condition of your engine thermostat can be confirmed with an operational test by dipping it in boiling water. It should spring open if it works.
The water pump should also be tested or inspected to rule out failure and the engine cooling fan should be observed to confirm that it runs at alternate low or high speeds.