EngineGuard Temperature Alarm System

As a sponsor of the JaguarForumsUK Great British Day Out we were asked to review another sponsor’s product, the Engine Guard Temperature Alarm. Effectively a bolt on Temperature Sensor for vehicles not only giving an accurate reading but also programmable to give the driver an audible alarm should the engine temperature rise above a set amount to avoid engine damage if the driver has not seen the temperature gauge.

When told about this product, as a Jaguar Mechanic, three applications sprung to mind of which this product would be a life saver. Firstly older Jaguars where the original gauge may not be as accurate as it could perhaps be. Secondly pre 1989 Jaguar XJ40 (of which I am an owner) fitted with Jaguars new and futuristic Digital Dash, so futuristic that the idea was ahead of the technology at the time resulting in poor quality soldering and intermittent loss of all dash displays. Thirdly, Jaguar XJ8/XK8 fitted with the 4.0 litre engine, unfortunately well known for overheating and terminal damage when it does. Having changed a number of these cars, the standard procedure seems to be the coolant level sensor failing or being bypassed, a slight coolant leak emptying the system without the driver knowing, and the temperature gauge not registering its overheated as there is no coolant to read. A recipe for disaster and another reason why the coolant level sensor must be working.

The kit supplied was the bolt on sensor kit, there is also an option for fitting into the coolant system but I felt the bolt on sensor was the most sensible option as it meant not having to drain the coolant which was only recently done, with coolant being quite expensive and a lot of classic Jaguars running Evans Waterless Coolant. It also seems ideal for air cooled Fiats or VWs etc. If you are due to have the coolant change then the wet system will be ideal.

We fitted the system to our Jaguar MK2 3.4 MOD. Fitting was extremely straight forward with everything you need supplied. It took about 30 minutes. The sensor bolted onto an existing point on the inlet manifold and the wires were easy to connect between sensor and head piece, and the headpiece into the fuses for a live feed. Programming the alarm trigger temperature was also straight forward with the instructions supplied. The kit also has the option to wire into the oil pressure switch on the car to alarm if the pressure drops.

Running the Jaguar over the course of the last couple of weeks has shown it to be very accurate, the original Smiths gauge sitting at 70 degrees and normal, with the Engine Guard showing approximately the same, which is very good news that the car is behaving. As you would expect from an engine built by ourselves our MK2 does not overheat! But to test the alarm I programmed it to 60 degrees and when it reached this temperature the alarm was spot on, and anyone hearing that alarm it certainly gets your attention to pull over and switch off before damage is done.

Overall this is a fantastic product, easy for the DIYer to install and very useful for our Jaguars. The only criticism is that for a classic car the head piece is too modern and looks out of place, however I have been informed a classic style gauge is being developed, with this being the case I thoroughly recommend it.

Reviewer: Henry Fryer, Julian Ferraro Jaguar Specialists 2020