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| ENGINE PROTECTION UNITS |
| What Temperature is Safe? | | In the days gone by, these specifications would have been classified as SAC Trade Secrets, today however, we are more than happy to reveal this information. | | Our ongoing efforts to constantly offer our customers the most recent technology available in the world will never stop. | | What we want to achieve with the new EGT gauge is that the client must be aware of what is happening and the client must be able to take correct action to ensure maximum mileage from his vehicle, before any unnecessary major expenses are incurred. | | No matter what the driving condition, altitude or even ambient temperature, the EGT should not exceed 770ºC. | |  | |
In fact, we are more comfortable with 720ºC for that extra peace of mind.
In most cases the maximum EGT will only be reached when driving full throttle, but with diesels that's more often than not. | | Towing even a small load would also bring out the maximum EGT. | | Some diesel turbos exceed the maximum permissible EGT while driving at a constant speed of 120 km/h. | The biggest problem is and will always be -
How will you know what the EGT is if there is no gauge to show you? | | Our experience is that with the help of the EGT gauge you can also achieve extremely good fuel consumption because it is directly related to the EGT. | | | | |
| What can Affect the EGT |
| There are a whole lot of factors, which can influence the EGT of a diesel turbocharged vehicle. The worst part of high EGT is that it snowballs and simply gets worse if you carry on driving. |
 Altitude: Altitude has an affect on EGT. Theoretically it shouldn’t, but it does, especially when the vehicle concerned doesn’t have an altitude compensator fitted. The altitude may not affect boost pressure, but it definitely does affect the air fuel ratio, which is directly proportional to EGT. Many of today’s diesel turbos don’t have altitude compensators. |
| Drop in boost pressure: If a vehicle is set up with 10 lbs of boost pressure at a certain rpm and for some or the other reason the boost decreases due to a hole in a pipe or cooler, the air fuel ratio is affected and once again it is directly related to the EGT. On vehicles with electronically controlled boost compensation, the difference is not as big but is still present. Electronically controlled systems may also pick up a lack of boost pressure, but 90% of the bakkies on the road today are not electronically controlled. |
| Different fuels: Fuel from 5 different pumps gives different EGT readings. In our opinion, only the viscosity or lubricity of the fuel changes slightly and as a result the pump’s automatic timing, changes, which result in rapid EGT change. |
| Incorrect air fuel ratio settings: This is a very delicate area, simply because a small variance or incorrect setting could result in 200º EGT change. The settings which are usually done in a "Pump Room" nine times out of ten change when the pump is exposed to the under bonnet conditions. We find it very difficult to understand why controlled conditions are used when setting up a pump and then the pump is fitted to an engine, which does not have controlled conditions, in fact it's everything but controlled under the bonnet of a vehicle. You could purchase a brand new vehicle and the settings of the pump under the bonnet could be incorrect, which results in extreme EGT's and ultimately into a slow process of engine destruction. |
| Incorrect water temperature: Here we have a situation where the water temperature can differ up to 15ºC and the temperature gauge in the vehicle will not move from the normal position. This is how the cars are built and unfortunately 15ºC has a huge affect on the EGT. |
| Incorrect pump timing settings: Here with electronically controlled pumps, the problem is far smaller but again 90% of the diesel turbo vehicles on the road today are fitted with mechanical pumps. The EGT is very easily affected if the pump timing is incorrect. Many factors can influence the pump timing, because the advance function is also mechanical. |
| Many other factors can influence EGT and we won't be able to go into detail in each case but to list a few which are most common: |
Contaminated fuel
Driver abuse
Blocked fuel filter
Towing or driving fast for long distances
Blocked air filter
Blocked exhaust system |
| As we said before, they all create a snowball effect and the problem is, one will never know when most of the above are happening. A simple gauge, which can monitor EGT, will indicate immediately if something is wrong. |
| What if the EGT limit is periodically exceeded? |
| Piston crown failure and cracking is very common, however different makes and models use different material for pistons and sleeves. Some can handle the excessive temperature better than others. |
| The first area that will take strain is the exhaust manifold and the turbocharger. | | Exhaust manifold cracks and/or broken studs are a first occurrence. The waste gate valve area in the turbocharger starts to melt and because one cannot see inside the turbo, you wouldn't know. | | The colouring of the turbo is one way of establishing the inner condition. | | If the turbo is a shade of blue, the damage is probably already there. | |  | |
| Once the waste gate has any sign of damage, the boost pressure will change and once again one wouldn't know because there is no boost gauge in the vehicle. |
| The cylinder head in the combustion area starts to crack, just light hair cracks at first and eventually they crack into the water channels. Piston crown failure and cracking is very common, however different makes and models use different material for pistons and sleeves. Some can handle the excessive temperature better than others. |
| Engines that continually exceed the permissible EGT, generally don't last more than 60 000km before they fail completely. Surely all this information will make one wonder why vehicles today aren’t all fitted with EGT gauges as standard equipment. |
| Fitting an EGT gauge will not affect your new vehicle warranty and is there to help preserve your vehicle's engine and save money in more ways than one. |
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