6.0 Powerstoke EGR System, EGR Valve, and EGR Cooler Explained
What goes wrong with the 6.0 Powerstroke EGR System?
The Why, What, and Where of the 6.0 Powerstroke EGR System
In 2003 Ford introduced the 6.0 Powerstroke to the world. This is the same engine that International calls the VT365. This engine has received a really bad reputation in the diesel world due to reliability issues. We will tackle one of the problem areas here today, the egr system.
Before I go any farther, please understand that the egr system is an emissions device. It is against Federal law to tamper, remove, or render an emissions system inoperable. Please understand that all the information in this article was collected from off-road only trucks and I do not endorse the removal or tampering with of any emissions system of a vehicle that is used on public roads. It is up to you and your mechanic to decide what steps you want to take in modifying your truck.
1. What is the EGR system and why do I need it?
One of the most frequently asked questions we receive is what is the EGR system and why do I need it? We don’t have to go into long technical descriptions here. EGR stands for Exhaust Gas Recirculation. To meet certain emissions standards, it is necessary to reintroduce exhaust gases into the intake air in order to bring certain elements in the exhaust within levels set for that year of truck. Of course you wouldn’t want to dump hot exhaust gas directly into the intake manifold, so that is why there is an egr cooler. The cooler has engine coolant running through it and looks very much like a regular radiator or heater core. The exhaust gas passes through this small radiator and lowers the exhaust gas to a temperature that it is able to be introduced into the intake system at. On the 6.0 Powerstroke engine, it is an extremely simple system consisting only of a cooler and a valve. When the engine’s computer decides the egr valve should open under certain conditions, the exhaust gas is let out of the cooler and into the intake manifold. And here we have the first hint of a problem; the exhaust gas is always in the egr cooler.
2. What goes wrong with this system and how can it hurt my engine?
The big problem here is heat. It is possible for a completely stock engine to produce exhaust gas temperatures well in excess of 1000 degrees. So imagine taking 1000-1500 degree air and constantly running it through your heater core day after day. How long do you think it would last? Next, put that heater core in an enclosed box that has to endure not only the high temperatures, but also 10-50 psi of exhaust backpressure that is built before the turbo between it and the exhaust manifold. Even though the cooler is made out of materials that are meant for higher temperatures, it is not a matter of if, but when your cooler will fail. Best case scenario is that the cooler just leaks a little coolant into the exhaust system and it passes out the exhaust and you just notice some coolant loss. Worst case scenario, exhaust pressure is able to enter a break in the cooler and enter the coolant system which only runs at 12 or so psi max. The high pressure will ruin head gaskets and oil coolers. They simply weren’t designed to withstand that much pressure in the coolant system. Also, the coolant system cannot keep the truck cool with that much pressure in the system. This is why you will hear about or may have experienced coolant puking out of the filler cap on the degas bottle after pulling a load up a long hill. The cap is made to bleed off pressure above 12-14 psi. The increased coolant temp and extra pressure being pushed in from the exhaust will push coolant right out the cap. We have a truck in the shop right now with a blown egr cooler and head gasket. The pressure in the coolant system had gotten so high that it blew one of the hoses right off the coolant bottle. This truck was a bone stock work truck. This blown cooler problem only gets worse when you put a programmer on the truck that raises exhaust gas temperatures several hundred degrees. If you put your programmer on the highest setting, hook to a heavy trailer, and then go tugging up a long grade, I suggest you put your mechanic on speed dial. You will need his services soon.
As if that all isn't bad enough, the egr cooler will break down the Gold coolant that is installed in the truck from the factory. The high exhaust temperatures in the egr cooler will cause some elements of the coolant to drop out and turn into a sludge material that will cause all sorts of problems in the coolant system. The sludge will start clogging up the oil cooler and will restrict flow through it. The next place the coolant heads after the oil cooler is the egr cooler. As the oil cooler becomes more and more restricted, the less flow through the egr cooler there is. This why you sometimes hear about people blowing egr coolers one after another in very short periods of time. The mechanic replaced the cooler but did not check the oil cooler to make sure it wasn't clogged. We suggest changing the oil cooler when doing an egr cooler replacement if your vehicle has over 100K miles. The test is to monitor oil temperature and coolant temperature with a scan tool. The two temperatures should never be more than 15 degrees apart under extended full load conditions.
The other problem with the system is that the egr valve constantly gets coked up with exhaust soot. The dirty exhaust gas passing by it deposits soot on the valve surfaces. Sooner or later the valve will get enough soot on it that it can’t close and operate normally. Exhaust gas is constantly pouring into the intake manifold now. This condition causes severe drivability issues, poor fuel economy, and low power. If you have owned a 6.0 Powerstroke for very long, you have no doubt replaced, cleaned, or had your egr valve checked because of this problem.
3. What can we do to fix this problem?
There are a couple of fixes to this problem. The first and most obvious is to simply remove or delete the cooler. Unfortunately, that would be against the law.
The other fix is to replace the cooler with a “performance” one that is not supposed to rupture. We do sell an 6.0 Powerstroke upgraded egr cooler and install them in applications that must have a functioning cooler. While it is a lifetime cooler it won’t solve all the egr issues. Even if the cooler will never pop with the better unit in there, you would still be getting exhaust gas into the intake system. If you have ever torn down a 6.0 Powerstroke, you would be amazed at the amount of soot that collects on the intake passages and intake valves. Letting dirty exhaust gas into the intake manifold is just a bad idea the whole way around.
4. Is there anything I can do to prolong my egr cooler life if I want to leave it in?
If you don’t want to remove your cooler for fear of black helicopters and fines for tampering with Federal emissions devices, there are a couple of things you can do. First off, the lower you can keep your exhaust gas temperatures the better. Installing a high flow exhaust will help lower your egts considerably. A bigger more efficient intercooler like the Banks Technicooler or the Spearco upgrade will also help. Installing a turbo that moves more air like the Garrett Stage 1 will also help lower egts. And lastly, installing a pyrometer to keep an eye on exhaust gas temps will enable you to back out of the throttle when they get too high. Also making sure you run oil that has the right certification for your engine will help keep soot down a little.
In conclusion, I firmly believe many of the horror stories of multiple blown head gaskets can be blamed on two egr cooler related things. First, a leaking egr cooler can cause the extremely high coolant pressures causing a head gasket issues. Secondly, many trucks get misdiagnosed as needing head gaskets because many mechanics don’t understand the engine. If you have smoke from your tail pipe that smells like coolant, your egr cooler is blown. The 6.0 head gaskets will almost never ever leak coolant into the cylinder like conventional gaskets. Likewise, blown head gaskets will not hydrolock a 6.0 engine either. It is coolant that ran out of the bad egr cooler and into the exhaust manifold then into an open exhaust valve. It is all too often we get trucks hauled in from different shops with these two symptoms expecting head gaskets and all we had to do was take care of the cooler.