C.J. Snyder is back with more tips & tricks to help keep a Ford 6.0 liter going strong! Be sure & check out Part I as well!
When talking about the Ford 6.0, the big issue that people have with them is the fact that the head gaskets love to blow out, and the EGR cooler loves to blow, causing plumes of white smoke to billow out of the exhaust like you’re fogging for mosquitos. Though not necessarily catastrophic, both of these issues are a big pain in the ass and cost the owners tons of money and down time.
The main cause of both of these issues are a combination of 2 things. 1; Navistar (parent company of International) cut corners wherever they could to save money and 2; proper maintenance is not performed, either privately by the customers, or by poorly trained technicians. There is one subsystem in the engine that causes more headaches for owners than either the head gaskets or EGR coolers; the High Pressure Oil System. There are many different points of failure in the system that can lead to either crank-no-start issues or hot-start issues, and I will attempt to work through them all in this write-up, as well as some fixes for them.
The first thing in the oil system I want to talk about is the High Pressure Oil Pump (HPOP), and this is confined to the 03-04 model years. In 05, International went through and redesigned many parts of the 6.0 to try and take care of all the problem spots found on the 03-04 engines, and they sort of succeeded. The HPOP on the 03-04 engines used some plastic parts on the inside that were prone to breaking apart and trashing the pump itself, and all the various other parts in the system. There really is no fix for the consumer other than to go to the aftermarket, where there are some all metal HPOP’s you can install to remedy this problem. 05-07 engines don’t seem to have this problem.
This is the revised 1-piece STC fitting. The threaded end goes into the back of the HPOP, oil flows through the center of it, and out through the center hole of the block portion. The outer 2 holes are for the bolts that attach it to the branch tubes under the HPOP.
Next comes the Snap-To-Connect (STC) fitting, probably the most trouble prone piece in the system. From the factory, the STC fitting was 2-pieces that snapped together with an o-ring and metal flange. One side threads into the back of the HPOP, facing the rear of the engine, the other side gets bolted to a block-shaped flange that the branch tubes tie into. The problem is at the o-ring in the middle of the 2 pieces.
The constant high pressures it sees coupled with the constant vibration of the running engine means that it has a nasty habit of failing and allowing the 2-halves of the STC fitting to separate. When this happens, the high pressure oil is able to simply bleed off into the crankcase, so the injectors never see it, and this leads to a crank-no-start problem. To correct this problem, Ford came out with an STC update kit that includes a new 1-piece STC fitting to alleviate the failures caused by the 2-piece fitting. You can buy the kit at your local “stealer”-ship or at an aftermarket supplier and either do it yourself, or have a shop do it. Just make sure that it is either a stealership or an independent shop that has lots of experience working on the Ford 6.0 liter diesels.
This is the dummy plug (on top) and stand pipe (on bottom). The flared, tapered end attaches to the branch tubes under the HPOP. The threaded end at the other end is what threads into the oil rail to seal it to the rail and apply a press fit to the tapered end where it meets the branch tube. The oil flows up through the center of the stand pipe and out through the cross drilled holes at the other end into the oil rail. The 03-04 style is different, with a special fitting that a braided stainless steel soft line attaches to that feeds the oil to the oil rail.
Next in line is the stand pipes and dummy plugs. This is another part that was changed in 05, so I will keep the discussion to the 05-07 engines. The standpipes are what takes the high pressure oil from the branch tubes to the high pressure oil rails in the cylinder heads. The stand pipes themselves are not the problem, but the O-rings that seal them are. The problem is that the seals can’t always handle the high pressures in the system, and they tend to either twist or tear and allow the high pressure oil to bleed off into the crankcase.
The tricky thing is that they tend to only do this when the engine is hot because the oil is thin. When it is cool and the oil is thick, the engine will crank up and start and run normally, but when you shut it down to run into a store or something, and come back out 10 or 20 minutes later and try and start it, the truck will just crank and crank until the batteries die or the starter burns out. The same problem happens with the dummy plugs. In case you are wondering what the dummy plugs are, they are to plug the excess holes in the oil rail.
The high pressure oil rails are able to be put on either side of the engine, so the port for the stand pipe to pass through would be in the back of the rail on one side of the engine, but when the rail gets switched to the other side of the engine, the port ends up being in the front of the rail, so International made 2-ports evenly spaced in the rail, so either port lines up with the stand pipe, but the other port needs to be plugged, so that’s why there are dummy plugs. When the O-rings on the stand pipes and dummy plugs started failing, Ford came out with some new ones that have some white Teflon rings under the O-rings to stabilize them and keep them from rolling and tearing.
This is a picture of the 05-07 high pressure oil rail taken straight from the Ford service manual. The 2 round openings in the upper wavy part are for the stand pipe and dummy plug. The 03-04 oil rail only had the straight lower part. Regardless of the model year, the lower part is what connects to the fuel injectors.
Now we come to the high pressure oil rails themselves. Again, this is something that was changed in 05. The 03-04 oil rails were just a straight cast iron pipe that fed the oil into the top of the injectors. Ford found that because of the action of the rail filling up with oil, then draining partially due to the injectors using the oil up, then refilling, a pressure wave would develop and start bouncing back and forth from one end of the rail to the other, causing a strange knocking noise and actually depriving the injectors of a constant and smooth flow of oil. So, in 05, International added the upper “W” shaped section and all the sections that criss-cross between the 2 sections. This addition helped to increase the capacity of the oil rail to stabilize the pressure in the rail, and the shape helps to negate any pressure waves that try and develop. The only real failure point in these is the cups of the fittings that go into the injectors, but these rarely fail. You can either replace the rail, or replace the cup with some aftermarket pieces.
Ok kids, even though this doesn’t specifically have to do with the high pressure oil system, it’s time to get to the single most problematic part of the entire engine; the oil cooler. It helps cause head gasket failures, it helps cause EGR cooler failures, and it causes the truck to overheat.
The head trouble maker of the 6.0; the oil cooler. Coolant goes in and comes out of the side with the elevated fittings, and oil goes in and out of the holes that sit flat with the housing. The oil filter housing sits on top of this, which sits in a recess in the valley of the block.
To understand why, you need to understand how the oil cooler works. Unlike other vehicles that have oil coolers that look like little radiators (called oil to air heat exchangers), the 6.0 used an oil to coolant heat exchanger. It sits under the oil filter housing in a depression of the valley of the block. It takes in engine oil and passes it through several layers of oil galleys that run the length of the cooler.
Here’s a shot of the oil galleys of the oil cooler. The oil goes in one side, flows across the cooler, and flows out. The coolant does the same thing, in layers that separate the oil galleys, so the layers go oil-coolant-oil-coolant, and so on.
It also takes in coolant and passes it through several layers of coolant galleys that sit in between the oil galleys that run the length of the cooler. The layers alternate, so there is an oil layer, than a coolant layer, than oil, coolant, oil, coolant, and so forth.
The heat gets transferred from the oil, through the metal that separates the layers, and into the coolant. The problem is that the coolant galleys tend to get clogged up; this happens for several reasons. One is that sometimes, casting sand from the block and head casting at the foundry gets left behind in the coolant galleys. Some 6.0’s have this problem, some don’t.
The sand gets carried by the coolant into the oil cooler, and it can’t make it through the small coolant galleys. The other cause of it getting clogged is the coolant itself. When Ford introduced the 6.0 engine, they also debuted a new coolant called Motorcraft gold. Suspended in the liquid was a series of dissolved additives called a “corrosion inhibitor package”. It was intended to stop electrolysis from occurring between the coolant and the cast iron of the block and heads and the aluminum of the front cover, water pump housing and oil cooler.
The problem is, if the coolant doesn’t get flushed enough, the additives fall out of suspension and end up as solids floating in the coolant. These solids end up clogging up the coolant galleys of the oil cooler. You can see what these solids look like by finding a 6.0 with blown head gaskets (shouldn’t be too hard to find, haha!)
You will see what looks like baby powder all over the degas bottle, the inside of the hood, and just about everywhere else under the hood on the drivers side. A secondary problem caused by the oil cooler getting clogged up is the EGR cooler failing. The coolant goes through the oil cooler, then the EGR cooler, so when the oil cooler clogs up, it restricts coolant flow to the EGR cooler, and allows the exhaust gasses to overheat it and bring the material of the cooler to it’s failure point, causing it to start dumping coolant into both the intake and the exhaust, and you get a whole lotta white smoke.
The best way to figure out if your oil cooler is clogged is to get a mechanic to look at the coolant temps and oil temps on a scan tool (or if you have a programmer at home like my EDGE Insight CTS, look at ECT and EOT), if the temps are more then 15 degrees apart at idle, chances are pretty good your oil cooler is clogged. The best way to avoid this is to flush your coolant every 30-40k miles. Ford says 100k on the coolant, but I call BS on that.
Standard practice for most vehicles is around 60k miles, but because of the oil cooler issue, I would go every 30-40k. Also, you can do what I did and install a coolant filtration kit. You can get them from a bunch of different places, I got mine from MKM Customs (Sinister Diesel). This will extend out your coolant flushing intervals, and save your oil cooler and EGR cooler, which will save you money. I also got my bypass oil filter kit from MKM Customs, and the 2 together under the hood look great, they just take up a bit of room.
This is the coolant filter kit to help keep the oil cooler from clogging up with casting sand and sediment in the coolant. The hose with the blue anodized aluminum t-fitting splices into the hose that feeds the heater core. It sends the coolant through the filter, and then returns it to the engine through the hose with the brass barbed t-fitting that splices into the overflow hose that runs from the radiator to the degas bottle.
The 2 photos above are just a bit of eye candy for you. This is a new water pump I got from Bullet Proof Diesel. The factory water pump uses a plastic impeller that can break. This one is all billet aluminum, with an anodized aluminum impeller, should last a hell of a lot longer than the factory one. The damned things so beautiful, I almost don’t want to hide it in the engine!