Open all the time

Open all the time

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Winter is upon us once again, and we are starting to get cooling problems in, or lack of movement on the temperature gauge and a poor cabin heater. I am amazed that people will drive with coolant gauges not working through the summer, and with no heater. It is as important in summer to have a coolant system working as it is in winter. Perhaps more so as the ambient air temperature is higher and therefore cooling capability is reduced. If the gauge is not working and you have no heater, the least of your problems are you will be using more fuel, it could be far worse, and you could do serious damage!

At Worcester’s Mobile Mechanic we are happy to talk to customers to diagnose the fault, and this is how we got the work on this vehicle. The customer called as the heater in the car did not work, and this prompted a series of questions:
Is it petrol / or diesel?
Does the temperature gauge work?
If stuck in traffic does the temperature gauge move?
When stuck, does the heater work?

After the customer’s response to these questions I diagnosed suspected thermostat failure in the open position. I explained that the stat was, “open all the time”. The customer happily booked the vehicle in.

The thermostat on the left (old unit) has clearly failed in the “open” position, and this is why the temperature gauge only moved when stuck in traffic! I used this as a training aid with the young apprentice, as normally the stat will fail partially open but this was clearly fully open and it was easier to explain how the thermostat worked and the effect it had on the coolant system. I explained to the apprentice, the engine was taking a very long time to warm up, and  it would probably never give the best thermal efficiency. This prompted a whole lot of more explanations.

Next time I will explain that we use to have two types of thermostat!

After the customer had the vehicle back she called to thank us, she had never had a superb heater before, and now the temperature gauge stayed in the middle all the time! A side effect will be she is now getting more miles to the gallon!

Remember… a badly maintained vehicle is a breakdown waiting to happen!