Excessive exhaust gas temperatures (or EGT’s) are a considerable risk to modern diesel engines. When excessive EGT’s are present, damage to the motor will result. This damage can ruin the bearings in the turbo or melt a piston causing catastrophic engine failure. Repairing damage like this in many cases can exceed the replacement value of the truck!
The causes of excessive EGT’s can create a very long list. The most likely suspects are, towing heavy loads particularly when driving uphill, performance modifications, electronic or mechanical failures and more. Because there is no one single cause for this problem, it is important to understand what is happening, the dangers involved and the steps you can take to prevent dangerous EGT’s.
The first thing to understand is how to interpret the temperature. What I mean is this, if I were to tell you that the EGT’s during a particular set of circumstances were 1000 degrees, most people would indicate that to be a “safe” temperature. This information leaves out a critical component that prevents the temperature from being properly interpreted. For example, the EGT thermocouple, which is the device that measures the temperature, must be placed in the proper location. If the thermocouple is placed in the exhaust so that the gases go through the turbo before touching the thermocouple, then its important to understand that the actual temperature of the gases coming out of the cylinder and into the turbo will be higher than the value displayed. In other words, the gases will have had some time to cool down before being temperature checked. If this is where the thermocouple is placed then it is important to understand that the actual temperature of the gas coming out of the cylinder is going to be considerably hotter than the value measured. We believe that the most appropriate place for the thermocouple is in the exhaust manifold close to the exhaust port of cylinder numbers 4 and 5. This will give the best chance to read the hottest temperatures available within the engine. Ideally this temperature is pre-turbo and in the manifold because there is less room for error during interpretation when measuring the hottest exhaust gas that we can. In other words, due to the concern about excessive heat, it is always best to read the temperature as close to the hottest location possible so there is less guessing as to how hot the temperature actually is.
Gauges are some of the most helpful and cost preventative investments that you can make for your truck. Here we discussed excessive EGT’s. However there are several other values that should be monitored by the driver to make sure that the vehicle is being driven in safe conditions. EGT is not the only critical temperature point. Transmission temperatures, differential temperatures and coolant temperatures must be monitored if the truck is to avoid the repair shop. Pressures are also vitally important. Fuel pressure, boost pressure and oil pressure should never be over looked. These values must be intelligently monitored otherwise costly, extreme engine damage can result.
We at Source Automotive are proud to offer an industry leading 2 year warranty on all of our gauges. We carry a full line of gauges for the diesel enthusiast. If you are unsure of which gauges are right for your application. Give the experts at Source Automotive a call and we will help you select which gauges would be best for your truck!