In part one of our car parts for beginners , we talked about how as a car owner, you will (all too frequently) have to put your hand in your pocket and shell out considerable amounts of your hard earned cash to keep your car running.

Cars need routine servicing, parts wear out and things break.  All of these things can be expensive and inconvenient but having some basic parts knowledge could potentially reduce some of that cost and keep you on the road for longer.

A basic understanding of how some of the key components of your car work, what the signs of wear are and how they are maintained can be invaluable. As the saying goes –  Knowledge is power! In This article, we’re going to take a look at Radiators, Engine fans and A/C Compressors.


Cooling system components

The radiator is part of your vehicles cooling system that keeps your car’s engine from overheating. The engine’s coolant gets pumped (by the Waterpump) through the radiator and cold air (aided by the fan) flows through the radiators cooling fins. This dissipates heat from the water into the air before it goes back into the engine to be used again.

How do I know if my radiator is faulty?

Leaking coolant?Cooling system components The most common issues with radiators are leaks, however, most leaks are actually from the radiator hoses and not the radiator itself. That said it is common enough for radiators to fail. Often holes can appear in radiators due to physical damage or corrosion. Clear signs of this are when you notice coolant laying under the car when its parked or regular loss of coolant after a short space of time.

Is your car overheating? Your car’s radiator is the main component of its engine cooling system. If your car is overheating it is hugely important that you check your radiator straight away as continuing to drive an overheating engine will cause more damage to your engine resulting in expensive repairs. You should never open the cap on top of the radiator or expansion tank when the engine is still hot as the coolant will still be extremely hot and could be under a lot of pressure and can squirt out and burn you

Is there sludge in your radiator?Cooling system components Your vehicle’s coolant should be yellow, green or red normally. Contaminants discolor the coolant making it a rusty brown colour, over time this can turn to sludge that is too thick to drain through your radiator and circulate around your engine. This sludge can also be caused by mixing different coolants. Some cars require a specific type of coolant and using the wrong type can cause damage to internal parts of your engine

Engine Fan


While the radiator does a good job of keeping the engine cool, it often needs some help. The engine fan keeps air flowing over the radiator, and is controlled by a thermostatic fan switch (these and coolant temperature sensors fail all the time). The fan is turned on when the coolant gets hotter than a set temperature. After the fan has cooled the engine coolant sufficiently, the control system turns it off again.


How do I check if my fan is working?

Visual check: Take the car for a drive and get the engine up to its normal operating temperature.  In newer engines the cars fan can be very quiet so to visually check your fan the best thing to do is lift your bonnet and listen closely.Cooling system components

Check the fuse!

When anything electrical in your car stops working the first thing you should check is your fuse box.
To find the fuse box location you should refer to your owner’s manual for your car. If any fuses are blown, replace them straight away and hopefully this will solve your problem!

Cooling system componentsIs your temperature sender working?
A temperature sender is a small sensor in the cooling system of your car that sends a reading of how hot your engine is running. If this sender is not working your engine won’t recognize that it is hot enough to require cooling which in turn can lead to your engine overheating.

Is your coolant level correct?

This is easy to check, there is a coolant reservoir that will be clearly visible in your engine bay. It is important to make sure that your coolant level is kept between the max and min marker.
If you’re not regularly checking your coolant and you do happen to have a leak, a tell-tale sign would be when your interior heater stops blowing hot air. This can happen if the coolant level in the system drops below a certain level.

When checking any parts along your cooling system it is important to make sure your engine has cooled sufficiently before you start working on it or you remove the expansion tank cap as the systems is pressurized and the coolant can be over 100 degrees centigrade.

A/C Compressor

Cooling system components

The A/C compressor is the heart of your car’s air conditioning system and provides the icy cold air that’s so welcome on a hot day. The most common reasons for an A/C compressor to fail are leaking seals, low refrigerant, leaking or not enough lubrication, airlock (causes knocking noise), A/C belt at wrong tension.

Regular use can help prevent some of these problems, so if you have air con but never use it, it is recommended that you turn on the A/C every so often so it can lubricate itself and keep from drying out. The most common reason that your air con systems aren’t working is that they’re simply out of refrigerant (often just referred to as being out of gas) You can buy DIY kits to refill your own air con and it’s pretty easy to do. They start at around €/£50. You can also get a mechanic or a specialist to do the job for you but obviously, you’ll be paying a bit of labor on top of that so expect something in the region of €/£60-120