Given the complexity of the cooling system, problems with maintaining correct engine temperature or with retaining coolant, might have a number of causes and diagnosis can be tricky. Many customers have come to us with what they think is a head gasket problem, and are greatly relieved when it proves to be a problem with other parts of the cooling system. When you bring your car to All Drive Subaroo, our technicians thoroughly inspect the engine compartment and cooling system to determine what work or service is required. Checks that we are able to perform include:

• Power vacuum bleed of system
• TK check
• Engine compression test
• Cooling system pressure test
• Fluid dye test
• Cylinder speed test
• Electrical diagnosis using Subaru SSM machine

One very common problem occurs when cooling systems are fully drained and then refilled, either as part of a routine service replacement of coolant, or following cooling system or head gasket repairs where the coolant is drained. Modern Subarus cannot simply be filled up with coolant from the header tank or directly into the radiator. If this is done there will be large pockets of air left in the system, and the engine will overheat. There is no bleed nipple on Subaru engines to ensure that all air is out of the system, and the only way to do this properly is by use of a special coolant vacuum purge and refill kit that sucks air out at one end, while drawing coolant in at the other. Not all workshops have this equipment available, but as a specialist Subaru service center, ADS does, as well as all other specialist tools and equipment required to service Subaru cars. Whatever the problem is, we can most likely fix it for you on the spot.

A few decades ago, car radiators were made from brass and copper, highly durable materials, and easy to repair. There used to be a thriving business in reconditioned radiators, and radiator repairs such as re-braised or soldered tanks, and flushed and cleaned cores. Modern cars however use much thinner aluminium cores and plastic tanks. When these fail, they often cannot be repaired. This has created a new market for replacement radiators, and after-market manufacturers, notably Chinese companies, have been quick to jump in. The Chinese built after-market replacements are less than half the price, but they are virtually non-serviceable. They are a copy of the OEM Subaru design, but the build quality is inconsistent. We have tried to install units supplied by customers, only to find that the mounting points do not precisely align, or the unit is slightly too wide for the mounting frame, requiring a little distortion to fit. We have observed that these radiators inevitably fail after only a short time, and in demanding conditions, simply fail to keep the engine cool. This is because they use less metal—one or two rows of honeycomb cooling cells instead of three, as in the OEM Subaru units, and high quality Japanese made after-market units. The Chinese units also use inferior seals to hold the top and bottom tanks on, and generally thinner gauge materials all round. The result, all too often, is overheating and an expensive engine repair that could have been avoided. OEM Subaru radiators, and other quality units built in Japan, are not cheap, but they are of very high quality. We keep a large stock of OEM Subaru radiators, and high quality Japanese built after market units in stock, and we are very aware of the importance of making sure your car engine stays cool and in optimum condition. Ensuring your car engine runs at the correct temperature, may involve a radiator fluid exchange, a simple part replacement or more complex repairs.