Overheating

"My car is overheating what shall I do?"

Firstly is it really overheating or is the gauge just telling you fibs. If it is a later Triumph with a voltage stabiliser and you are getting high temperature readings on your gauge.

"Have you also noticed the fuel gauge misreading?"

"Have you recently run out of petrol when the gauge still showed a quarter of a tank?"

"Does your temperature gauge read well into the red but your car shows no sign of boiling over?"

The reason could be that voltage stabiliser fixed to the back of your speedo or on the back of the dash on some Spitfires and GT6's. Because it links the supply to both the temperature and fuel gauges it gives a false reading on both, usually an over reading, and usually more pronounced on the temperature gauge, don't ask me why ask an auto electrician.



voltage stabiliser 128484 or 148876

Other electrical malfunctions, which can give false gauge readings, include faulty temperature sender switches mounted on the side of the water pump housing casting.

An easy way to check what may be giving you problems in this department is to put the temperature switch supply wire to earth (with the ignition switched on). With a volunteer sat in the car watching the gauge they should see the needle rise smoothly to full scale.

If not suspect problems with stabiliser or gauge if it does then the switch is the culprit.

Enough of electrical maladies your car may be genuinely overheating usually accompanied by steam and boiling noises!

Of course the worst culprits in the overheating department are the latest model Spitfires, something to do with Triumph reducing the area of the radiator as the engine capacity increased and the grille area reduced, that makes sense! Triumph must have known this because the American market cars came equipped with a full width radiator similar to that fitted to all earlier Spitfires when they were only 1147cc's and had a much larger grille aperture.

Many years ago we tooled up to make this full width radiator, part number RKC2117, all Spitfire 1500's should be fitted with one by law!
 

full width radiator RKC2117

 Things can often get worse after an owner has gone out and spent a fortune on electric fans and or oil coolers and the overheating problem has persisted or more usually got far worse.

Electric fans and oil coolers mask the root problem and don't cure them in fact they often make things far worse.

"Where do most after market electric fans fit on Triumphs?"

Smack bang in front of the radiator core masking anything up to 40% of the core, look how big that motor is, and how much area the fan blades mask when both stationary and when rotating, even the mounting brackets mask parts of the core. If you can't get the fan on the engine side of the radiator sucking warm air through it then take it off and throw it in the bin.

Even we sometimes don't listen to our own advice and quickly learn the lessons all over again.

Many years ago I built John Kipping a very special Herald. It was built initially to recreate the 1959 Trans African Herald prototype proving run immortalised in 'Turn left for Tangiers'.

Built with 1500 running gear and a full width radiator I made the mistake of fitting an electric fan ignoring our own advice. Anyway John and I set off on the long slog down through Europe to Gibraltar to catch the ferry across to Morocco. As we crossed through Spain and things warmed up it became apparent that engine temperature seemed to be increasingly controlled by the fan cutting in, a worrying sign as we would be crossing the Sahara desert in a few days time! Things came to a head in the Atlas Mountains in the Sahara, on the climb the fan was working continuously barely stopping us from boiling over, and then to cap it all we lost all the water from the radiator. The fan was of the type that bolts directly through the core and one of those mountings had worn through a tube. The hole was fixed with Araldite (wonderful stuff should be in everyone's toolkit), all our drinking water was put in the radiator, and the fan was thrown at a passing camel!

"Guess what?"

The car immediately ran cooler and from that day to this has run without any fan whatsoever, lesson learnt.

Another great memory from that trip was chasing the famous Marakesh Express train on a parallel road for many miles, it wasn't much of a chase though as the 'Express' seems to be flat out at 50/60mph! I digress.

Oil coolers, for racing cars only, enough said, no?

For 99% of Triumph road cars an oil cooler is at best an unnecessary expense at worst it is damaging your engine.

"Where is it mounted?"

In front of the radiator, see above.

Is it controlled by a thermostat and you mainly do short trips (less than 25 miles), then its probably never opened. Its not controlled by a thermostat, then all you are doing is extending the engines vital warm up time and drastically accelerating rear, increasing fuel consumption, and pollution.

Back to radiators,

"When was the last time it was recored?"

"More than 10 years ago, don't know?"

On a poorly serviced car that may have been used irregularly with poor quality antifreeze or corrosion inhibitors (Glycol based antifreeze is best Bluecol etc) your core may be blocked and no amount of 'back flushing' will shift it, unless you use nitroglycerene! A re-core or exchange radiator is often the easiest and safest route.

Water pumps not a lot to go wrong here they either work or leak but still keep working.

Picture the scene Club Triumph Round Britain 1998, 2am in the wilds of Scotland far from civilisation, rain and sleet, nice and cosy in the TR5 other half driving me fast asleep. Suddenly it gets very cold, wake with a start to see the temperature gauge reading zero and the wife complaining that the heater has packed up miles back down the road. You guessed it the gland seal has gone on the water pump allowing water to escape out of the tell tail hole in the water pump body emptying the radiator in the process.

One very rare problem we encounter on cars that continue to overheat when all else has been checked or renewed is corrosion in the void in the water pump housing where the pump impeller usually fits. Very slight erosion here can have a drastic affect on the efficiency of the water pump. Substitution with a better S/H housing is the only answer.

I won't insult your intelligence with the more obvious causes of overheating, number plates, badges, rally plaques in front of grilles etc, but it still amuses us when we see poor old 1500 Spitfires so adorned at club days.

A poorly tuned engine can have dramatic effect on how hot your car runs and really should be the first step in your investigation.

As a rule of thumb if your 4 cylinder Herald/Spitfire doe's any less than 30 miles to the gallon on a run, pinks (detonates) under load or runs on then it is in need of a tune up. There is no good reason why a properly tuned carefully driven 4 cylinder should not do 50 mpg on a run, I have done it myself many times in Heralds.

"One last thing has the car started overheating since a winter lay up?"

If yes then check that the brakes aren't binding. Handbrake mechanisms have an annoying habit of seizing up during lay-ups as well as wheel cylinders, we have no direct experience of this ourselves because we use our Triumph's all year round, and so should you!