What are most common engine problems with Ford 6.0L Diesel?

Answer 1

Some of the biggest issues with the Ford 6.0L diesel has been linked back to all the emissions standards the EPA implemented in mid-2003. One of the first issues we ran into was turbo related. What was happening was the VGT unison ring was getting rusty, carbon-up, and would stick to the housing which in turn wouldn't move the vanes that directs exhaust gas at different angles into the exhaust side turbine creating the almost instant boost and low end torque. Ford came out with many different programing strategies and re-enginered many of the parts of the turbo to minimize the sticking. But still to this day the best of the best turbos still eventually stick because its a product of it's dirty, sooty, environment. Luckily they are cleanable and the cost is much cheaper then replacing the entire turbo. Other diesel manufactures you cant recondition the turbo or they wont warranty that type of repair. That was one of the first problems and many,many more have followed.

Here's a breakdown of the biggest issue by model year.

2003-early 2004 had aluminum High pressure oil pumps. I've seen them explode, crack, break gears, and most of all lose of prime when hot. They have a much better high pressure oil delivery system to both cyl heads and injectors. Rarely did we have high pressure oil leaks on these models if the ICP was low typically it was the HPOP in most cases. One up side to these models was the egr coolers were much more ridgid and didn't have as many issues. The early models run a little different due to programing ford did with how the VGT operates. Basically they removed the EBP sensor as the PID that would determine necassary VGT actuation %. Ford was using "after the fact" (exhaust back pressure) to determine what VGT% and MGP (Boost) was needed per engine load. Doing that caused other problems and the newest PCM re-program fixed most the issues. On these models when the engine is at idle no vehicle speed you can actually hear the engine learning the VGT by constantly moving the unison ring to 3 different positions every opertunity possiable at idle. They are Low learn%, Medium learn% and High learn%. The idea was to keep the unison ring free of carbon, soot, and rust. It seems to work better. This model have a much lower sticking rate then any other model year. They do stick just not as much as other model years without this programing feature. Ford learned their lesson and went to "before the fact" to determining how much boost is needed by using the MAF/IAT1 sensor. So with all this said the early 03-mid 04 models their turbos didn't stick as much, egr coolers were much better, high pressure oil delivery to heads and injectors was much better but the aluminum HPOP were junk.

So now we go on to the late 04-07 Model Years. Ford really got alot of things wrong in my opinion. Let's start with the high pressure oil system. Ford re-designed the HPOP. It went from alumunium to cast iron and this pump rarely fails good news right.......?? When ford re-designed the pump they also re-designed the oil delivery system to the injectors and the oil rails that deliver the oil to the injector. It is nothing but problems!!! They used a snap together fitting (STC) that connects the branch tube to the HPOP. The STC fitting will blow off causing many different starting problems such as crank no start, only starts cold when hot crank no start, oil leaks at rear of engine and high repair costs. It's bad enough it now won't start and now the really bad news when this fitting blows off it can bend the branch tube (the branch tube goes to each head delivering oil from the HPOP to the stand pipes then to oil rails on top of injectors) to a point where it hits the engines rear cover and cracks it causing a oil leak as well!! It typically bends to a point where it can be bent back into place. Ford came out with a couple design's to secure this fitting. Eventually they made a screw-in style fitting that works very well. Now to the other HPO problem. When they re-designed the injector oil rails not only are they way bigger then the early models they put a dummy plug in both of them and the o'rings eventually corrode and now you have either a no start, or hard start, or won't start when hot. Yes these 2 little o'rings on the plugs leak enough oil from the rails so not enough oil pressure is built to fire the fuel injectors!!! Why didn't ford use the early HPO delivery system from the 03-mid 04 which had very little problems and pair it with the bullet proof cast iron HPOP that never fails and they would of been fine!!! So all 6.0L have a weak link in the HPO system only the later models can be up graded using up date kits and rail plugs.

They re-designed the egr coolers in mid-04-07 which have nothing but problems. The inside fin core is more compact then the earlier models. This causes much more heat, much more plugging from exhaust gas soot causing heat. When they get too hot they fracture internally causing coolant to flow into the turbo, intake, and into your combustion chambers and lots of white smoke. Now the main cause for egr cooler failure was finally linked to a plugged oil cooler element which restricts coolant flow to the egr cooler. Little to no coolant going to the egr cooler and the hot exhaust gas inside..... it's gonna crack! So now if your egr cooler is blown you also need to replace your oil cooler element as well. No questions asked. Ford will not warranty the egr cooler if you don't replace the oil cooler as a pair!

Head gaskets fail as early as 30k and you will do this repair by 100k or so. They use a multi-layer metal head gasket, over time and the 18:1 compression ratio pushing up on the heads long enough the head bolts stretch causing the clamping force to be weakened spreading the layers and the compression stroke finds it's way in between those layers which in turn pressurizes the cooling system to well over 20 psi in some cases. Causing overheating problems, degas bottle overflow, and costly repairs.

All models fuel injectors are prone to fail. Due to cleaner EPA standards and much higher pressure at the injector tip (for more complete combustion and cleaner emissions) the tolerances inside the injectors now days are so small and tight even the smallest contaminance will cause problems for modern day injectors. Not just Ford with injector problems!!! Change your fuel filters!!!

One last thing lack of maintence is the #1 cause of alot of these problems. Do your service work it will save you in the long run. Or just don't buy a 6.0L or do i love the 6.0L it's paid for alot of my things i have today. I just wanna maybe inform even one person to stay away from this engine it's going to cause you problems, i know first hand try and get a 7.3L that's a much more solid engine. Hope this helps. Good luck.