How to run a common rail

[High Wire]

Since I am new to larger Diesel engines, I have asked similar questions.

My boat has a turbo-charged Cummins 5.9L QSB engine rated at 380hp. Unfortunately, I have the opportunity to spend some time with a very experienced and senior Cummins mechanic. I asked him some of those very questions. This is what he said.

1. Start up and make sure the idle is smooth. Then leave the dock. Allow the temps to rise to close to normal operating temps before adding a lot of power.

I would add to #1 to quickly check for continuing water flow from the exhaust.

 

[dhays]

1. Start up and make sure the idle is smooth. Then leave the dock. Allow the temps to rise to close to normal operating temps before adding a lot of power.



I would add to #1 to quickly check for continuing water flow from the exhaust.

Yes, that is an important one. I usually step off the boat to release lines and I check the exhaust at that time.

 

[catalinajack]

This is all gleaned from the truck forums and experience. The Bosch high pressure pump, particularly the Va-4 and to a lesser extent the Va-3 is extremely sensitive to any water in it, self destructing and sending detritus through the fuel system ruining the injectors. On a Ford pickup, the repair bill is around $10K, you know it happens frequently because there is a Ford p.n. for the kit of parts required. This is also happening on the Duramax (Isuzu) and less often the Ram (Cummins) engines. All of them use the Bosch pump and injectors.

The consensus is to avoid (and Ford specifically warns against) any additive that claims to disperse water, or has any alcohol in it as that makes the water more soluble in diesel and helps get it by the filters. Some additives claim to condense water from suspension - which would be good because large droplets are easily filtered - but I don't know if I believe them.

How applicable all this is to a marine diesel is unknown (to me anyway) but the QSB5.9 in my boat is nearly identical to the RAM pickup engine of a few years back, and the QSB6.7 is nearly identical to the current RAM pickup engine. Marine diesels usually have better and more filters which has got to help. The Racor 500 and 1000 filter elements come in AquaBloc form, this has a hydrophilic coating that is supposed to help reject water - but Racor warns that this coating ages and you should not use them more than a year old.

I've not heard of a bunch of problems on the marine Cummins, but I'm not eager to experience them first hand either so I change the filters with fresh ones regularly, and don't use additives that aren't forthcoming about their ingredients. The only ones I use in the boat are BioBor Jr (a fungicide) and Enerburn (a metal based fuel borne catalyst). The former to control bugs and the latter to reduce carbon soot. Both of these have independent published scholarly scientific studies to support their efficacy, most fuel additives do not and are more in the snake oil category.

DDW, the failure of the Bosch CP4 fuel pump in vehicles is due to insufficient lubricity in ULSD fuel. Yes, water in fuel is death to pumps and injectors but it is not common in vehicles or boats for that matter. Our filters take care of that. Plus, water in filter sensors alert the user to that problem well before water can make its way to an engine.

"Why Does it Fail?

The short answer: lack of lubricity.*Lubricity is most commonly defined as the ability of a fluid to minimize the degree of friction between surfaces in relative motion under load conditions.
The CP4 injection pump creates higher pressures with less volume than its predecessor, the CP3 pump. Although this makes it a more efficient pump, the lack of volume creates a lack of lubrication since these pumps rely on the diesel fuel to act as a lubricant.* In addition to the higher pressure and lower volume, the removal of sulfur from modern diesel fuel (Diesel #2 or Ultra-Low Sulfur Diesel)*also destroys compounds that exist in the fuel naturally that would normally contribute to increased lubricity.*Some fuel resellers mix lubricity-increasing additives into their fuel prior to sale, but this is not consistent and not well-regulated. Using a commercially available diesel fuel additive can be helpful, but cannot be guaranteed to prevent CP4 pump failure."

The Bosch CP4 was used by General Motors from 2011 to 2016 on Isuzu-designed Duramax engines. GM changed to a Denso pump in subsequent years. When a CP4 pump fails it literally explodes sending aluminum bits throughout the fuel system. I have read many reports of repair bills ranging to $14K. The cost is related to having to replace everything, the pump, fuel lines, fuel cooler, injectors, and having flush the fuel tank.

Many CP4 owners retrofit with a CP3. I own a 2003 Duramax with 7,600 hours on the clock (327,000 miles). The CP3 still lives but, of course, it could fail tomorrow from normal wear. However, I have yet to read about a catastrophic (exploding) failure of a CP3. Nor have I ever had any water in my fuel. That brings me to the topic of fuel additives and the insufficiency of fuel lubricity at the pump for engines using high pressure fuel pumps.

This issue is well-documented. From the day I owned my Duramax I have used an additive that increases lubricity. There is no question that doing so increases pump and injector life. Boats equipped with high pressure pumps are no less at risk from insufficient fuel lubricity than vehicle engines. I have used several brands of additives over the years. One is the Standyne product. Another is DieselKlean. For a long time now I have been using the Archoil product. I do think that all improve lubricity so, is one better than the other? Probably not to any measurable degree. I like the Archoil product because it requires just one ML/gallon, easy to measure and less volume than others.

As for my Ford Lehman and similar low tech engines fuel lubricity is probably less of an issue. But, if I were the owner of a Cummins QSB, for example, there would be no doubt about using an additive that improves lubricity. My goodness, most boat owners change oil well before it is necessary (cheap insurance). An additive is truly cheap insurance. Yes, Valvtec fuel containes lubricity improvers but is not available in many locations.

And, DDW, lubricity improvers are not snake oil. You do realize that all refiners add lubricity improvers to their ULSD to bring lubricity up to a minimum standard. Unfortunately, that minimum is insufficient for today's high pressure fuel pumps and injectors, including your QSB's.

 

[FF]

If I were contemplating a common rail engine I would go to Pro Boat Builders and dig up the back issue on how to filter for best results.
Their claim was modern fuel from the pump is not near clean enough and must be cleaned.

A filter bank 3 or 4 in a row works , but will still pass a chunk every so often.

The only known method of obtaining clean fuel is with a good centrifuge, these have come down in price so are not just for the 50 meter boats.

While fuel polishing is in vogue a far simpler method is to have a deep bailable sump , so the crap doesn't build up inside a simple box for fuel.

Oil floats on water so regardless of how tiny the water drops , they will slowly fall into the sump.
A de emulsifier will help cluster the water and fall into the sump.

On a used boat with boxes for fuel perhaps the answer would be to somehow install a day tank with a sump..

 

[Roger Long]

A filter bank 3 or 4 in a row works , but will still pass a chunk every so often.

This is what a filter expert who was a consultant to filter manufacturers told me. Filters are not screens and the size ratings are statistical. He said to think of them like a pile of sticks. Lots of things being dropped through them will be stopped but things much larger than the rating will get through. The repeating pass through of a polishing system running all the time the engines are will remove even smaller particles than the filter rating.

 

[dhays]

The repeating pass through of a polishing system running all the time the engines are will remove even smaller particles than the filter rating.

That is what my engine does. It returns more fuel than is burned. So it is filtering the fuel all the time the engine is running

 

[Arc]

My QSB 380 will not come up to operating temp until 1,400 rpm. This is probably due to being in a light slippery boat [ 6 ton ] I believe low temp could cause long term damage . I normally run 2,000 rpm so not really an issue.

 

[DDW]

DDW, the failure of the Bosch CP4 fuel pump in vehicles is due to insufficient lubricity in ULSD fuel. Yes, water in fuel is death to pumps and injectors but it is not common in vehicles or boats for that matter. Our filters take care of that. Plus, water in filter sensors alert the user to that problem well before water can make its way to an engine.

.....

And, DDW, lubricity improvers are not snake oil. You do realize that all refiners add lubricity improvers to their ULSD to bring lubricity up to a minimum standard. Unfortunately, that minimum is insufficient for today's high pressure fuel pumps and injectors, including your QSB's.

The lubricity of ULSD fuel is a contributor, but so is water. Ask any diesel garage. There are tons of people with Fords, failed fuel pump and therefore fuel system, telltail signs of water in the fuel (this is easily determined from rust specs on various components) and Ford will not honor warrantee. Water In Fuel light never lit. This is quite commonly reported.

Lubricity improvers are not snake oil, nor are cetane improvers. The problem with many or perhaps most additives is they are circumspect about what is in it, and the label reads like it will solve world hunger and cure cancer. Just be sure you know what is in it, and what it does.

 

[FF]

"I believe low temp could cause long term damage ."

Low loading is more damaging long term as the engine requires a load have enough combustion pressure to seal the rings .

A 400hp engine creating push at the rate of 2 GPH has a rough life.

 

[OldDan1943]

My QSB 380 will not come up to operating temp until 1,400 rpm. This is probably due to being in a light slippery boat [ 6 ton ] I believe low temp could cause long term damage . I normally run 2,000 rpm so not really an issue.

You can adjust that temp with a different thermoset but be careful in your selection. You dont want the temp to climb up out of the normal range.

 

[rslifkin]

You can adjust that temp with a different thermoset but be careful in your selection. You dont want the temp to climb up out of the normal range.

In theory, yes. But in some cases, lightly loaded diesels are moving enough air through them that they just never reach thermostat temp.

 

[catalinajack]

The lubricity of ULSD fuel is a contributor, but so is water. Ask any diesel garage. There are tons of people with Fords, failed fuel pump and therefore fuel system, telltail signs of water in the fuel (this is easily determined from rust specs on various components) and Ford will not honor warrantee. Water In Fuel light never lit. This is quite commonly reported.



Lubricity improvers are not snake oil, nor are cetane improvers. The problem with many or perhaps most additives is they are circumspect about what is in it, and the label reads like it will solve world hunger and cure cancer. Just be sure you know what is in it, and what it does.

I agree that Fords have problems. Interesting that GM Duramax do not have problems with water. Even with the Fords, I'll hazard a guess that the problem is always, always being a strong word, user error. Being boaters we are keenly aware of water in fuel being a hazard. We religiously, more or less, monitor our filters for water. Yet, how many drivers of vehicle just turn the key and go, rarely ever doing engine checks. I suspect these Ford guys simply do not check their filters, unwisely relying on their water-in-fuel sensors. In 324,000 miles of driving my Duramax, I have never had a drop of water in my fuel. Perhaps it is not the Ford engine's fault but a poorly designed fuel supply system.

 

[Hippocampus]

Been told the return from the engine is inadequate to address fuel concerns. Even if you have occasion bumpy days fuel tanks are not sufficiently agitated to prevent sludge collection on the bottom. Given you need only a small bit of water in the fuel the surface area of the interface layer between fuel and water is little changed once there’s even a small bit of water covering the bottom of the fuel tank. Your return pump neither has enough volume nor force to agitate the fuel nor disturb the sludge. Add in baffles and you’re doing even less.
If you want to polish fuel you need
Pick up at the way bottom. Return from the top.
Enough high speed force and volume to agitate the tank. Enough to completely filter the entire contents of the tank(s) 3 times in a short period of time. Let’s say ~8h.
Your fuel return does none of the above.

 

[twistedtree]

If you want to polish fuel you need
Pick up at the way bottom. Return from the top.
Enough high speed force and volume to agitate the tank. Enough to completely filter the entire contents of the tank(s) 3 times in a short period of time. Let’s say ~8h.
Your fuel return does none of the above.

And I would argue that 90% of the "fuel polishing systems" on boats are wholly inadequate as well.

 

[Hippocampus]

TT- what did you spec?

 

[Codger2]

And I would argue that 90% of the "fuel polishing systems" on boats are wholly inadequate as well.

 

[DDW]

I agree that Fords have problems. Interesting that GM Duramax do not have problems with water. Even with the Fords, I'll hazard a guess that the problem is always, always being a strong word, user error. Being boaters we are keenly aware of water in fuel being a hazard. We religiously, more or less, monitor our filters for water. Yet, how many drivers of vehicle just turn the key and go, rarely ever doing engine checks. I suspect these Ford guys simply do not check their filters, unwisely relying on their water-in-fuel sensors. In 324,000 miles of driving my Duramax, I have never had a drop of water in my fuel. Perhaps it is not the Ford engine's fault but a poorly designed fuel supply system.

Put it context, perhaps 1 in 1000 - 5000 Fords have had this happen - it hasn't happened to my Ford either. I doubt Duramax owners are any different that Ford owners WRT maintenance and there are plenty of complaints on the Duramax forums about pumps exploding. The Ford has a water trap filter with a drain immediately after the tank pickup with a WIF sensor. However if you pump from a contaminated tank and get say a quart or two of water, you will never know that happened and it will instantly overwhelm a Ford, Duramax, or even a Racor 1000 filter. Not having a drop of water in the fuel indicates luck, nothing else. Boat fuel docks pump a lot more fuel typically than service stations, and hopefully maintain their tanks and filters better. But when you buy it at some remote place in SE Alaska or out in the Bahamas, your luck might run out.

My point was that common rail engines have tight tolerance pumps running at very high pressures, and piezo injectors that are very sensitive to any foreign material. They don't like dirt or water, and yes, they are sensitive also to lubricity. So be careful what you put in your tank.

 

[Fletcher500]

I spoke to an engineer at Cummins about this a few years back. TT sums it up well in his earlier post.

 

[BandB]

And I would argue that 90% of the "fuel polishing systems" on boats are wholly inadequate as well.

I would argue that 90% of the "fuel polishing systems" on boats that I've seen described here are not fuel polishing systems but simply filtering systems. They don't have centrifuges or other polishing equipment. Therefore, they do half the job.

 

[twistedtree]

TT- what did you spec?

Mine is designed to be a transfer and filtering system, but it has some polishing properties as well. My big storage tanks are quarantined fuel storage. All machinery draws exclusively from a day tank, and my transfer/filtering system is used to move fuel from a storage tank to the day tank. So fuel never gets to the day tank without first being filtered and run through a water separator.


If water or other contamination get past the filter/transfer, there is a sump in the day tank where water will migrate, and where solids will settle. The sump in equipped with a water sensor, and a drain so you can drain off accumulated stuff. That covers everything except contaminants suspended in the fuel.


For anything suspended in the fuel, every consumer has it's own racor filter/ water separator, so another pass at cleaning out anything that got past the first Racor, and that didn't settle out in the day tank sump. Then of course the on-engine filter(s).


I think the only place bulk contamination will come from is if I take on a crap load of fuel, which sooner or later will happen. But I should be able to extract clean fuel out of that via the transfer system. And even if I'm changing filters frequently, I should be able to keep up with consumption and keep the day tank topped off.


Now all this is aimed at keeping contaminants out in the first place, and I think that should always be Plan A. But if you do get a load of bad fuel, or you have an older or neglected boat that has accumulated crud, then you are facing tank cleaning, That's where you need a jet of fuel that can agitate and blast all the crap loose, get it in suspension in the fuel, and get filtered out by the polisher/cleaner. I think periodic tank inspections (maybe every 10 years) are prudent to see if a scrub is needed.


Where people really seem to get screwed is when their tanks have crud in them laying in wait. Then you get the boat in bad seas and the sloshing fuel does the agitating and blasting and puts all the crud in suspension where it promptly overwhelms your operational filters.


Despite all the effort, I think my system still has a few areas where I could get in trouble. There probably always are, and the trick is to just try to minimized them. It's always risk mitigation, not risk elimination.


I could get a really bad load of fuel, and exhaust my supply of filters while transferring. The up side is that I'm sure I could get some amount of fuel to the day tank and keep running for a day or more, especially if I slowed down. So it wouldn't be a sudden death, giving opportunity to work around the problem. But I could eventually run out of usable fuel. That said, I think all this can happen to any fuel system. None have infinite filtering capabilities. Or do they? Maybe an Alpha Laval does?


I could also somehow end up with crap in my day tank. In that case, my transfer system is set up so I can draw from the very bottom of the day tank, filter, and return to the day tank. That's classic polishing, if I got in a situation where there was something that needed polishing. It wouldn't scrub, but it would filter.


And my transfer system could fail. If it's the pump, I have an identical pump for oil transfer, and could swap that one in. Alternately, if I believe I have clean fuel in my big tanks, I can still gravity transfer from them to the day tank. That would completely bypass the filtration system and violate the isolation between purchased fuel and consumed fuel, but in a pinch, it's possible.


Fuel transfer, by the way, is 3 gpm which is the limit for a Racor 1000. So 180 GPH which is just about the capacity of my day tank. Polishing a storage tank would take 5 or 7 hrs for a single pass, depending on which tank.



Then there is the scenario that I haven't thought about, and that's the one that will happen....

 

[twistedtree]

I would argue that 90% of the "fuel polishing systems" on boats that I've seen described here are not fuel polishing systems but simply filtering systems. They don't have centrifuges or other polishing equipment. Therefore, they do half the job.

Isn't the difference just the amount of filtering?

 

[BandB]

Mine is designed to be a transfer and filtering system, but it has some polishing properties as well. My big storage tanks are quarantined fuel storage. All machinery draws exclusively from a day tank, and my transfer/filtering system is used to move fuel from a storage tank to the day tank. So fuel never gets to the day tank without first being filtered and run through a water separator.


If water or other contamination get past the filter/transfer, there is a sump in the day tank where water will migrate, and where solids will settle. The sump in equipped with a water sensor, and a drain so you can drain off accumulated stuff. That covers everything except contaminants suspended in the fuel.


For anything suspended in the fuel, every consumer has it's own racor filter/ water separator, so another pass at cleaning out anything that got past the first Racor, and that didn't settle out in the day tank sump. Then of course the on-engine filter(s).


I think the only place bulk contamination will come from is if I take on a crap load of fuel, which sooner or later will happen. But I should be able to extract clean fuel out of that via the transfer system. And even if I'm changing filters frequently, I should be able to keep up with consumption and keep the day tank topped off.


Now all this is aimed at keeping contaminants out in the first place, and I think that should always be Plan A. But if you do get a load of bad fuel, or you have an older or neglected boat that has accumulated crud, then you are facing tank cleaning, That's where you need a jet of fuel that can agitate and blast all the crap loose, get it in suspension in the fuel, and get filtered out by the polisher/cleaner. I think periodic tank inspections (maybe every 10 years) are prudent to see if a scrub is needed.


Where people really seem to get screwed is when their tanks have crud in them laying in wait. Then you get the boat in bad seas and the sloshing fuel does the agitating and blasting and puts all the crud in suspension where it promptly overwhelms your operational filters.


Despite all the effort, I think my system still has a few areas where I could get in trouble. There probably always are, and the trick is to just try to minimized them. It's always risk mitigation, not risk elimination.


I could get a really bad load of fuel, and exhaust my supply of filters while transferring. The up side is that I'm sure I could get some amount of fuel to the day tank and keep running for a day or more, especially if I slowed down. So it wouldn't be a sudden death, giving opportunity to work around the problem. But I could eventually run out of usable fuel. That said, I think all this can happen to any fuel system. None have infinite filtering capabilities. Or do they? Maybe an Alpha Laval does?


I could also somehow end up with crap in my day tank. In that case, my transfer system is set up so I can draw from the very bottom of the day tank, filter, and return to the day tank. That's classic polishing, if I got in a situation where there was something that needed polishing. It wouldn't scrub, but it would filter.


And my transfer system could fail. If it's the pump, I have an identical pump for oil transfer, and could swap that one in. Alternately, if I believe I have clean fuel in my big tanks, I can still gravity transfer from them to the day tank. That would completely bypass the filtration system and violate the isolation between purchased fuel and consumed fuel, but in a pinch, it's possible.


Fuel transfer, by the way, is 3 gpm which is the limit for a Racor 1000. So 180 GPH which is just about the capacity of my day tank. Polishing a storage tank would take 5 or 7 hrs for a single pass, depending on which tank.



Then there is the scenario that I haven't thought about, and that's the one that will happen....

I think the use of a day tank is fairly standard for long range cruising and a good idea. Seems your system is well designed to deal with 99.9% of all issues. Now, you mention getting a load of bad fuel. Have you looked at any of the testing equipment available? Water is fairly easy to test for at the start of fueling. Contaminants a bit less common. Kits for water are about $10 per test. For bacteria is about $20. We normally only test for water and we do so every time we fill. Highly unlikely to have bacteria without water. Only twice have we ever found water, but likely saved us considerable trouble those two times.

This is the kit we use:

https://www.fleetfueltesting.com/buy-diesel-fuel-tests/test-for-water-in-diesel-fuel

And here are others:

https://dieselcraft.com/fuel-test-kits/

https://www.dieselfueltestkit.com/

 

[twistedtree]

I think the use of a day tank is fairly standard for long range cruising and a good idea. Seems your system is well designed to deal with 99.9% of all issues. Now, you mention getting a load of bad fuel. Have you looked at any of the testing equipment available? Water is fairly easy to test for at the start of fueling. Contaminants a bit less common. Kits for water are about $10 per test. For bacteria is about $20. We normally only test for water and we do so every time we fill. Highly unlikely to have bacteria without water. Only twice have we ever found water, but likely saved us considerable trouble those two times.

This is the kit we use:

https://www.fleetfueltesting.com/buy-diesel-fuel-tests/test-for-water-in-diesel-fuel

And here are others:

https://dieselcraft.com/fuel-test-kits/

https://www.dieselfueltestkit.com/

I'll check them out. Others have mentioned them, but I have never used one. Seems like cheap insurance when buying from an unknown supplier.


So you have had fuel test positive? I'm not sure how much I have just been lucky, vs the benefits of sticking with reputable, volume suppliers. One thing I never do is buy while a truck is delivering fuel.

 

[BandB]

I'll check them out. Others have mentioned them, but I have never used one. Seems like cheap insurance when buying from an unknown supplier.


So you have had fuel test positive? I'm not sure how much I have just been lucky, vs the benefits of sticking with reputable, volume suppliers. One thing I never do is buy while a truck is delivering fuel.

Trusting my memory as it's been a while, but once was outside the US and in an area you might worry about and the other was early spring just after heavy flooding and the marina was very embarrassed they had not caught the problem, but we had.

 

[catalinajack]

Put it context, perhaps 1 in 1000 - 5000 Fords have had this happen - it hasn't happened to my Ford either. I doubt Duramax owners are any different that Ford owners WRT maintenance and there are plenty of complaints on the Duramax forums about pumps exploding. The Ford has a water trap filter with a drain immediately after the tank pickup with a WIF sensor. However if you pump from a contaminated tank and get say a quart or two of water, you will never know that happened and it will instantly overwhelm a Ford, Duramax, or even a Racor 1000 filter. Not having a drop of water in the fuel indicates luck, nothing else. Boat fuel docks pump a lot more fuel typically than service stations, and hopefully maintain their tanks and filters better. But when you buy it at some remote place in SE Alaska or out in the Bahamas, your luck might run out.



My point was that common rail engines have tight tolerance pumps running at very high pressures, and piezo injectors that are very sensitive to any foreign material. They don't like dirt or water, and yes, they are sensitive also to lubricity. So be careful what you put in your tank.

DDW, as I mentioned earlier the problem Duramax owners have been having with exploding pumps is confined to the Bosch CP4 pumps, not the earlier CP3s. Many owners have retrofitted with CP3s. Perhaps I have been lucky with mine. Perhaps it is because I have always used a lubricity improver. Perhaps it is because I added a lift pump which CP3-equipped trucks do not have OEM. Perhaps it is because I added a pre-filter and do not use the puny OEM filter. Interesting to note that you acknowledge that lubricity is a problem. I fully expect my CP3 pump to someday wear out but not explode. If I were to buy a 2011-2016 model Duramax I would immediately replace the fuel pump with a CP3, add a lift pump, and upgrade the filtration. In any case, boat owners with high pressure fuel pumps would be wise to consider using lubricity improvers. Pick one. Steve D'Antonio recommends the Stanadyne product but there are plenty of others. What slays me is that many who post here angst endlessly about lightning strike possibilties and ignore something like this which is real and very likely.

Point in fact - here we are talking about fuel polishing. I ask all, how many boaters truly need to worry about this? Risk is relative to where one boats, is it not? Assess the risk, equip to address the risk, not someone else's risk profile. How about this? All boats should have a water maker on board because one never knows if one is going to run out of water.

 

[North Baltic sea]

My QSB 380 will not come up to operating temp until 1,400 rpm. This is probably due to being in a light slippery boat [ 6 ton ] I believe low temp could cause long term damage . I normally run 2,000 rpm so not really an issue.

Hi,

have you checked the thermostat, i have the same cummins and it heats up about 1.6nm on the way rmp 830

NBs

 

[ronobrien]

Was brought up to warm up a diesel before leaving, let it cool down before shutting off (good for turbos especially ) and if not run with a fair load run it near WOT to burn off carbon periodically.

Now with newer boats all being common rail I am confused.
If run at very low load for a length of time should you still run it at or near WOT shortly before shut down ?
My crude understanding is given efficiency of fuel burn no carbonization should occur so maybe this isn’t necessary.

Been told running oil through it and slowly cooling the turbo by leaving it on idle for 5-10 minutes before shut down is a good idea. There’s no such teaching for the turbocharged common rail diesel in my Jeep. Why? What’s best practice for a marine common rail?

Been told compared to NA mechanical diesels common rail is super sensitive to bad fuel. What if any precautions do you take? ?additives? On board polishing? Additional filtering beyond OEM stock? Have you followed CaptWil’s advice? Do you periodically have the yard polish your fuel for you? Do you only store with full tanks? Have you added water traps to fuel tank vents? What do you do?

Any and all thoughts appreciated but please include the reasoning behind your advice. Thanks

A little warm up (2 minutes at 1200 rpm) is not a bad idea if in cold climates. It's not so critical in more temperate climates. Running at full throttle periodically is more to raise cylinder pressures. The rings seat best under high load. This helps prevent cylinder wall glazing and retains ring seal. It's a good idea. "Cooling" down a turbo is a bit of a misnomer. When run under moderate to heavy load, the turbo spins at VERY high rpm. If the engine is shut down before the turbo has a chance to "spool down", you stop the oil supply to the turbo shaft while it is still spinning rather fast and could quite possibly damage the turbo bearings. In the real world however, by the time you have come into the dock you have likely been running at near idle for 5 minutes or more

so you have already allowed the turbo to spool down. The most important thing you can do prolong the life of a diesel is to run it HARD for 5 minutes or so every time out. It is worth 5 minutes of fuel. Diesels LOVE to work, and like it best when you make them do so. I think regardless of how you run a diesel you are still gong to get carbon build up in the mix loop. That's just the way it is.