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What do you think about EGR & DEF deleting on these trucks?  When pulling up steep grades this truck temp goes to the top end of normal range some say with deleted engine they will run cooler.  

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w ranch...I've watched the EGR and DEF removal trend with curiosity.  Both measures would be illegal by EPA standards and cause a truck to fail the emissions test in states like California or Nevada with visual inspection and tailpipe readings.  That is enough reason to leave these systems alone, but I have some practical concerns as well.

EGR (exhaust gas re-circulation) is a system designed to lower the upper cylinder temperatures in an internal combustion engine.  Above 2500 degrees F, the engine's combustion process produces nitrogen oxide (NOx).  So, the intent of EGR is to lower combustion temperatures and cool the upper cylinders.  In a gasoline engine without EGR, temperatures can soar above 4800 degrees F, enough heat to melt many metals.  For that reason, I have always cautioned against removing an EGR system or valve from a gasoline engine.  The same logic should apply to a diesel engine.  You're already concerned about engine/coolant temperatures rising under load on grades, eliminating the EGR valve could create more of an issue here.

I did some research, and the concern around EGR on the 6.7L Cummins engine is that the exhaust gases on this system are cooled by an engine cooler.  The cooler relies upon engine coolant to cool the hot EGR gases.  Below are two links to products designed to eliminate the EGR cooler and the EGR valve.  I'm not endorsing either product, simply using them as examples of how/why a delete might impact the engine cooling.  Logically, if engine coolant is the means for cooling the EGR valve or gases, the engine cooling system has to eliminate the heat introduced to the coolant in this process.  There is also discussion of eliminating soot build-up in the EGR valve and clogging the valve, which would seem more likely with a diesel burn than gasoline.

https://www.rudysdiesel.com/product-p/rdp-egrd-6.7c-13-1.htm [Note that this kit requires "delete tuning" after installation; be clear that this step is required.]

http://www.ebay.com/itm/EGR-Valve-Cooler-Delete-Kit-Fits-10-14-Dodge-Ram-2500-3500-6-7L-Cummins-Diesel/231299728940?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D38530%26meid%3Ddef739a4ff2c4793a94761b4c03a240c%26pid%3D100005%26rk%3D1%26rkt%3D2%26sd%3D401019393180

Worth noting is that both the EGR system and DEF are passive, by design they should not impose a performance penalty on the engine.  DEF is added downstream from the engine to continue the combustion burn and further clean up the exhaust.  EGR is not a "driven" device nor does it impose a load on the engine.  It should, if functioning properly, help cool the upper cylinders during the combustion process.  This is intended to lower NOx in the exhaust system.

Note: Here's an interesting article on bio-diesel fuel and other ways to lower NOx: https://en.wikipedia.org/wiki/NOx#Biodiesel_and_NOx.  This helps clarify the aim of emission devices or fuel types.

So, the trend toward eliminating the EGR or DEF must be concerns around 1) heating up the coolant and giving the engine's cooling system one more heat source to dissipate and 2) the nuisance of soot buildup in the EGR valve itself.  In the case of DEF, there's the obvious cost factor of adding DEF, but this is also a part of the vehicle's PCM/ECM control monitoring; tampering with the DEF system can lead to engine trouble codes and other service-related issues.

Would I remove the EGR system or DEF system?  Not if I owned a Ram with the 6.7L Cummins engine and this kind of OEM equipment.  (I live in a state with emission inspection for both gas and diesel vehicles.)  The DEF is the price of ownership, and those I know with these systems do not think DEF is a big issue.  Admittedly, it's easier for me to say this with our 2005 Ram 3500 5.9L Cummins engine.  The engine has no EGR nor is the chassis equipped with a catalytic converter or DEF system.  That's the way the truck came new.  Lucky me?

As for engine heat, I am concerned that you're running that warm.  Are you getting an engine code that indicates improper fan speed for the engine speed?  Our engines are notorious for the fan clutch failing periodically, and at 156K miles, my fan clutch is hinting that it's not up to par.  Not sure about your truck's mileage, but if the cooling issue is recent and has not existed since day one of ownership, I would consider checking the fan clutch function.  

Note: You have the G56 manual transmission, which is actually a big plus on engine cooling as there is no transmission cooler on the engine nor in front of the radiator.  On our truck with the 48RE automatic, we have both transmission coolers, and a hot running transmission can tax the cooling system.  As a point of interest, there is a manual transmission cooler (finned, oil-to-air not coolant related) for the G56 and other transmissions with the standard PTO cover size: https://www.genosgarage.com/product/fc-6-spd-dg/transmission-coolers.  This would not lower engine coolant temperature but would contribute to less stress on the G56 under load.  There is a provision for a temp sender on the cooler, too.

I'm uncomfortable when my engine creeps to 210-degrees F with it's OE thermostat setting of 190-degrees F.  I have only seen this level of heat during the summer when pulling a 6% long grade with 8,400 pounds of trailer in tow plus luggage and 110 gallons of fuel, a GVWR near 17,300 pounds.  The gauge is well below the upper edge of the Normal range, so I'm not damaging the engine in any way, but I'm used to seeing a 200 degrees F peak when not towing a trailer.

In my case, I'm going to replace the fan clutch unit as a matter of course.  If your 6.7L is running above its thermostat setting in cooler weather when not trailering, I would consider a mild cooling system flush, replenishing the anti-freeze/coolant and installing a new OE Cummins or Mopar thermostat.  I am currently running a new Cummins/Mopar thermostat, fresh coolant and a new belt tensioner and belt.  My heat range relates to either the fan clutch unit beginning to fail or the aftermarket (allegedly "tow friendly") performance tuning set for maximum performance.  After installing a new fan clutch unit, if the moderate warm-up on grades with the trailer in tow persists, I'm tapering down on the performance engine tuning.

Do you have any kind of aftermarket performance software tuning on your Ram Cummins 6.7L engine?  Have you changed the thermostat and coolant recently?  If so, what is the thermostat setting?

Moses

 

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No this truck is all stock and I only use to pull trailer and it always does this when its hot, I am going to say 90 F or higher  while pulling trailer up steep grade .  I do here the fan speed increase when the temp starts going up. The state I live in does not have any emission inspection or any other type of inspection I would say I am about the only dodge out here that is not deleted. and yes it has fresh  mopar fluid the water pump went out last summer so new pump and fluid I think they put new thermostat I will check. Anyway if the older Cummings did not have EGR why would the 6.7 need them. as far as deleting DEF I think it is for just putting larger pipe to get cooler EGT's , I am not looking to hot rod this truck just cool it down and get a little more power. I understand about legal part and also the engine code I think the tuner takes care of that . So from a mechanical stand point for longevity would the engine run cooler and with more power deleting these items. 60k on the miles

 

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I will have to do 67500 EGR service soon where they will clean EGR cooler and lines and replace crank case filter $750 for the service work.  I think it is 200 bucks plus a smarty tuner for engine codes to delete these items, I also watched an interesting video about the carbon foot print that the EGR and DEF systems add to the environment do to the extra fuel burn caused by EGR and catalectic convertor. plus the carbon foot print with the production of all the plastic DEF bottles and boxes not to mention the  fuel burn to deliver product to stores and or to fuel island at truck stops anyway the carbon foot print is larger by a lot than if we did nothing. we might see some changes to the EPA soon. I am all for clean air but I am not convinced this is the way. I think this stuff is just costing money and heating my truck up therefore decreasing the service life of 6.7?  I never knew about the cooling effect of the EGR on the gas engine and I was not sure if you said that carried over to the diesel.  

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w ranch...If the video you watched is accurate, I understand your case against the EGR and DEF.  However, before considering the delete or modification of your system, I suggest reading this quick 6.7L Cummins ISB emissions system rundown by Bruce W. Smith.  Bruce and I both wrote for OFF-ROAD Magazine years ago, and I value his comments at Hard Working Trucks:  http://www.hardworkingtrucks.com/exhaust/.  I also value his tips on how to save some money trying to maintain one of these very expensive exhaust systems.  You do have 100K miles of warranty on the emission system, fortunately.  

Also, here is an excellent rundown of each emission device on your engine and chassis:   http://www.cumminshub.com/emissions.html.  Pay particular attention to the EGR description and SCR on your 2013 model.  In addition to the EGR system, SCR and DEF further reduce NOx.

As for my comments about the role of EGR, the cooling effect of the EGR would be the same for a diesel, and the goal is the same:  Lowering the combustion process temperature to reduce NOx.  Recall that NOx occurs above 2500 degrees F.  The only reason for an EGR system is to lower NOx, whether gasoline or diesel engine.

I did some research, and here is the direction Cummins is now going with emissions.  Note that the latest Stage V engines, including the B6.7L, will not use an EGR valve.  However, they will continue to rely upon an updated and more efficient DPF/DEF and SCR system:

https://cumminsengines.com/cummins-reveals-egrfree-new-engine-lineup

If your truck's EGR system is actually underlying an engine heat-up issue, the cause is the EGR system's method of reducing temperatures of the valve and exhaust gases: the use of a cooling system bypass cooler.  In this design, the coolant/cooler drops the hot EGR valve and exhaust gases temperature before recycling these gases.  Typical EGR systems on gasoline engines do not use a coolant/cooler.  The EGR valve is not cooled, and the exhaust gases come straight out of the exhaust stream and go directly into the intake manifold.  On a diesel, you have an air intake plenum/manifold and individual cylinder fuel injectors.  On the 6.7L Cummins ISB, the EGR exhaust re-enters the engine through the intake manifold, slightly diluting the incoming air with the EGR exhaust gases, which does lower the combustion process temperature and simultaneously the upper cylinder temperatures.  This reduces NOx emissions.  Downstream in the exhaust system, the passive SCR and DEF reduce the NOx level even more.

Moses

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Very interesting, I will read this. I wonder why they are not using the EGR any longer? And Thank you so much for the info. will check back after I look at these links.

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You're welcome...The Cummins discussion at Europe describes how they've eliminated the need for the EGR in the Stage V engines.  Fine tuning of the injection plus more refinement of the DEF/SCR system primarily...I'm installing an R2.8L high tech Cummins four in our XJ Cherokee this spring, and that engine does not use EGR, either.  It easily meets emissions standards.  

If you're curious, I interviewed Steve Sanders of Cummins Repower at the SEMA Show in November: http://www.4wdmechanix.com/advance-adapters-and-cummins-2-8l-diesel-engine-conversion-for-jeep/.  He mentions the emissions strategy for this four-cylinder crate engine, which Cummins is confident will pass 50-State legal emissions at California.  Steve describes the equipment involved.

Enjoy the read!  Happy New Year, too.

Moses

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Very nice. I have my Dad's old 1984 dodge Ram 150 with 318 going to check into that 4 Cummings for that . Ok so do you think its the EGR cooler that is heating up the 6.7 and I am still not understanding how the heated exhaust routed back into the intake is cooler than the outside air temp going in there.

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w ranch...You must have heard Steve Sanders comment on this R2.8L Cummins powering F350s and school buses in Brazil.  The horsepower is rated just over 160 in the crate engine, not extraordinary, but the kicker is the torque:  nearly 270 lb-ft by 1600 rpm and holding that torque level to 3200 rpm.  That kind of flat line high torque is unusual and valuable.  I'm gaining over 40 lb-ft of torque, coming in at a lower rpm than the 4.0L inline six gasoline engine and not dropping off within any reasonable highway speed in the overdrive gear.

Regarding the EGR function, you're right to wonder how hot exhaust can lower NOx.  Recall that it takes a combustion temperature drop to below 2500 degrees F for oxides of nitrogen or NOx to quit forming.  This is a chemical phenomenon.  The incoming (recycled) EGR exhaust gas dilutes the incoming clean air.  This introduction of spent fuel offsets a lean condition.  It's the lean condition, typically occurring at lighter throttle, that creates Oxides of Nitrogen or NOx.  The increased proportion of oxygen (i.e., a leaner air/fuel ratio with a higher oxygen percentage) raises the combustion process temperature.  That higher temperature creates the NOx.

By introducing the EGR's spent fuel/exhaust to the incoming air stream and combustion process, the remaining particles in the exhaust help overcome the lean condition and change the ratio of oxygen in the combustion process—without significantly enriching the fuel mixture.  

Note:  This should not be confused with introducing more unburned or raw fuel to overcome a lean condition. The exhaust, at least in theory, has already burned a considerably high percentage of the combustible elements.  The incoming air charge, being diluted by the EGR's spent fuel/exhaust, will not have as high an oxygen content.  Therefore, the combustion process itself is less "lean" and will burn at a lower temperature, and there is a reduction in NOx.  By design, the dilution has only a slight impact on performance, though it does reduce the available volume of fresh air/oxygen coming through the air induction system by a relatively small amount. (Compare the port size of the EGR valve to the intake plenum opening.)

From gasoline engines we learn that EGR functions efficiently when the engine is not idling and not under heavier throttle. As the throttle valve opens to a larger degree, a richer air/fuel ratio condition occurs. (Think of acceleration or an increased load that requires a wider throttle opening.)  Those of us who have worked on EGR systems know that the typical EGR valve's vacuum diaphragm routes to the carburetor (later the EFI throttle body) at the ported vacuum source.

The EGR valve by design opens at higher ported vacuum in a gasoline engine.  Ported vacuum is highest at the initial throttle tip-in and continues through lighter throttle settings.  As the throttle valve opens further, it no longer creates ported vacuum.  Note that this is easy to observe with a vacuum gauge hooked to a ported vacuum source as the throttle opens.  Ported vacuum is the same as distributor advance vacuum on older engines. 

Ported vacuum is a simple way to actuate the EGR valve coincidentally with the leaner burn or higher oxygen percentage in the combustion process.  As the throttle continues to open and ported vacuum tapers off, the EGR valve closes.  Richer air/fuel mixtures do not create NOx because the combustion temperature naturally drops with the richer mixture.  The EGR system is not needed to cool the combustion process because the oxygen level in the richer air/fuel ratio is not too high.

So, as you logically wondered, it's not about the heated exhaust cooling the combustion process, it's about the spent/burned fuel (EGR gases) diluting the available oxygen to overcome a lean condition—without raising the hydrocarbon level much.  Any remaining HC in the EGR gases gets burned again in the combustion process.

This raises the question: Why does Cummins need a cooler on the EGR valve?  I'm guessing there are two reasons:  1) the diesel exhaust is by nature very hot from the high compression burn, and 2) the EGR valve and its exhaust gas temperature need to stay within a reasonable temperature range to prevent risk of detonation and engine wear or damage.  

Detonation is what we hear as knock or ping.  We know that a diesel engine doesn't need spark plugs, the fuel ignites spontaneously from the high compression and introduction of fuel under very high pressure. Like you surmise, this is hot exhaust, and with the high compression and high injection pressure diesel cycle, introducing higher temperature exhaust gases, just released from the combustion process and flowing through the EGR valve, could wreak havoc. 

Compression ratio and injection pressures are much lower on gasoline engines.  A naturally aspirated or even turbocharged gasoline engine requires a trivial amount of injection pressure when compared to diesel injectors.  Naturally aspirated gasoline engines with carburetors or EFI do not force fuel into the chambers or cylinders like diesel injectors do.  By comparison, a diesel engine's fuel injector pressures are very high.

Moses

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