Keeping Your Aston Martin’s Thermostat at peak efficiency

Your Aston’s thermostat is a relatively straightforward device, but it plays an essential role in regulating the temperature of your engine. Sitting between the cylinder head and your car’s radiator, it modulates the movement of coolant – preventing its flow while your engine warms up, and allowing it to circulate freely once your engine has reached its optimal operating temperature. 

In some modern Aston Martins - particularly 2005-2017 V8 Vantages - the integrated gasket attached to the thermostat is known to fail after 5-7 years of regular use. Thermostats can also fail if your engine overheats or your coolant becomes fouled – a process that often clogs the internal workings of your thermostat and prevents it from working properly.

DB7 interior and dashboard

What Happens If My Aston Martin’s Thermostat Fails?

Generally speaking, thermostat failure does one of two things: if your thermostat fails while it’s in the open (or partially-open) position, coolant will flow freely between your radiator and your engine. 

This prevents your engine from reaching its normal operating temperature and will decrease performance. A thermostat valve that’s stuck in the open (or partially open) position will also prevent your Aston from coming out of its cold start enrichment phase, which means that your car will be running ‘rich’ or over-fueled until you fix the thermostat.

This decreases fuel efficiency and puts unnecessary strain on your engine. Over time, the high hydrocarbon content of your exhaust gases will also cause permanent damage to your catalytic converter and exhaust system. 

Alternatively, your thermostat could get stuck in the closed position. This prevents fluid from circulating between the radiator and your engine – causing your engine to overheat and risking permanent damage to your Aston Martin.

It goes without saying that a stuck or failed thermostat should always be replaced as soon as possible. If you think your Aston Martin’s thermostat may need to be replaced, get in touch using the form on this page.

We’re independent Aston Martin specialists with over 30 years of hands-on experience, and we’re ideally placed to help you troubleshoot a faulty thermostat. 

We’ve also got the dedicated workshop space, equipment and expertise needed to help you swap out a failed thermostat –  or carry out more extensive repairs to ensure that your Aston Martin’s liquid cooling system is operating at peak efficiency. 

Diagnosing Problems With Your Aston Martin’s Thermostat 

It can be relatively difficult to diagnose a failed thermostat, but there are some tell-tale signs that you can look out for. 

Because most V8 Vantage thermostat failures occur when the rubber seal or gasket surrounding the thermostat degrades and bits of debris are allowed to infiltrate the mechanism, the thermostat normally sticks in the open position. 

This means that the first and most obvious sign of thermostat failure is a ‘cold’ engine that never really reaches full operating temperature. If you think your engine might be running cold, we recommend going for a short drive. If you start with a cold engine and drive at a moderate speed, you should see the temperature or coolant gauge on your dashboard rising after 2-3 minutes of motoring.

If the gauge hangs or never quite makes the half-way mark, your thermostat is probably faulty and needs to be checked by a specialist. 

In the rare instance that an Aston Martin thermostat has failed in the ‘closed’ position, you’ll see the opposite problem. Coolant won’t be able to reach your car’s radiator and you’ll see the temperature or coolant gauge rising rapidly during normal operation. 

Other signs and symptoms of a faulty thermostat include sudden changes in cabin temperature, malfunctioning heaters and/or coolant leaks but in our experience, these are less commonly observed in Aston Martins. 

How Do Pugsley & Lewis Replace Aston Martin Thermostats?

When you bring your car in to have the thermostat checked, we’ll start by running a full diagnostic on your coolant system. 

This means plugging a computer into your diagnostic port so that we can read any error messages passed from the engine control unit, manually checking all the hoses, connectors and pipes that move coolant through your engine bay and examining the thermostat to see if it shows signs of damage. 

If we’re confident that your thermostat is faulty, we’ll remove the necessary hoses and brackets; disconnect the damaged part and replace it with an OEM thermostat. We can also replace your thermostat with a more durable, aftermarket part if you prefer. 

Once this is done, we’ll reassemble your cooling system and test your Aston Martin: checking that it runs well in a variety of conditions and gets up to temp in the timeframe we’d expect.

Want To Talk To An Aston Martin Specialist?

We’re always happy to help. Simply reach out using the form below and someone will be in touch to talk about your Aston Martin’s thermostat. 

As one of the UK’s foremost independent Aston Martin workshops, we’re the safe pair of hands your car deserves.