Ecodiesel power derating as temps rise?

[CrazyCooter]

Diesel engines actually do better the hotter they get. Unfortunately this whole system exists for the sole purpose of reducing N02out the tail pipe. In order to do that, they have to introduce O2 to cool the combustion chamber below the NO2 producing threshold which is about 2400 degrees. This of course makes the combustion less efficient and introduced soot into the combustion chamber, intake manifold and EGR - All the typical symptoms that have plagued Diesel engines for years and why the DPF and EGR delete even exist. It also creates a more back pressure which for a turbo is less efficient because it has to do more work. So you introduce a problem, then use DPF to try and fix that problem and to keep it all in check, I’m guessing the ECU derates power to ensure that when the combustion gets too hot (sustained towing in hot temps over grade) that the EGR can keep emissions in check. So I personally don’t think it’s a design problem. I think it’s a meeting diesel emissions solution that was designed in. The reason for derating is a complete hypothesis on my part.. but I think it’s to pass emissions. I’ll bet if you remove all that crap, you’ll have cooler temps. I think what people are doing with cooling is a bandaid to the bigger issue or “solution” depending on how you look at it. Cooling things externally will only get you so far (but maybe enough for an individuals needs). It will always be relative to the load and ambient temps over time. I’ve seen videos on delete systems and in the Jeep eco diesel it looks like a nightmare. Anyway, just my thoughts

The thought had crossed my mind about the derating being designed ut to keep certain emissions under a threshold. That said, if the oil is kept cooler and it is what cools the pistons.....may see reduction in combustion chamber temps? If nothing else, the coolant temp won't go nuts and overheat?

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[Rat2Desert]

Diesel engines actually do better the hotter they get. Unfortunately this whole system exists for the sole purpose of reducing N02out the tail pipe. In order to do that, they have to introduce O2 to cool the combustion chamber below the NO2 producing threshold which is about 2400 degrees. This of course makes the combustion less efficient and introduced soot into the combustion chamber, intake manifold and EGR - All the typical symptoms that have plagued Diesel engines for years and why the DPF and EGR delete even exist. It also creates a more back pressure which for a turbo is less efficient because it has to do more work. So you introduce a problem, then use DPF to try and fix that problem and to keep it all in check, I’m guessing the ECU derates power to ensure that when the combustion gets too hot (sustained towing in hot temps over grade) that the EGR can keep emissions in check. So I personally don’t think it’s a design problem. I think it’s a meeting diesel emissions solution that was designed in. The reason for derating is a complete hypothesis on my part.. but I think it’s to pass emissions. I’ll bet if you remove all that crap, you’ll have cooler temps. I think what people are doing with cooling is a bandaid to the bigger issue or “solution” depending on how you look at it. Cooling things externally will only get you so far (but maybe enough for an individuals needs). It will always be relative to the load and ambient temps over time. I’ve seen videos on delete systems and in the Jeep eco diesel it looks like a nightmare. Anyway, just my thoughts

This explanation makes a lot of intuitive sense to me. A sudden derate just doesn't seem like a normal way for overheating to work, it is some arbitrary temperature that is not for protecting the engine. It very much seems like a bandaid solution, perhaps added downstream of the original engineering and done under protest.

At the end of the day I "can" live with it conceptually, but derating should be done gradually and with plenty of warning, along with documentation in the manual.

 

[Gladihater]

It’s actually pretty common in diesel design. Check out this article: https://otrperformance.com/blogs/quick-tips/your-cummins-has-a-5-mph-def-derate-spn-5246-what-now. We can call it a safety mechanism, or for engine longevity or for emissions. In any case, I’m sure it’s there for some reason.

 

[Gladihater]

For what it’s worth bulletproof diesel now makes an upgraded EGR Cooler. Maybe that will help with sweating, although it doesn’t state that’s the purpose.

 

[@californiajeeping]

Got the bypass filter and cooler installed with a few hundred miles of comparison complete.

The first 4 pics were done after the exact same drive. Only difference is time of day. On this drive with factory set up I would see peek oil temp at 240*. The pics were taken after coming to stop. The drive is a gradual climb with lots of corners. Average speed is about 45mph

Factory

Bypass filter and cooler. No fan.
Edit. This pics is the last pic in post.

Bypass filter and cooler with Fan On.

Bypass filter and cooler with Fan On plus Water Wetter added to the coolant.

As you can see not much difference. The difference I saw while driving was the peek oil temps. The first pic was 240*, second pic was 237*, third pic was 235* and fourth pic 231*. The biggest difference was adding the Water Wetter to the coolant. Maybe the factory uses a not so “cool” coolant for the EcoDiesel.

Today we also did the drive that caused my first experience derating (National Forest). I derated due to hi temps causing many false sensor readings. Not specifically oil temp. When the derate happened I immediately started looking at oil temp for the rest of the trip home. Had to stop many times to cool off to get home that day. On this day the oil temps peeked at 248* and consistently showed above 240*. I traced this to wire harnesses directly above the power steering pump.

Today I never had a Peek oil temp above 235*.

The Bypass filter and cooler system has added 3 quarts of oil to the system. At 25 PSI oil pressure the flow rate is .75 quarts per minute.

The cooler is cooling the oil by 75* plus. I’m only estimating this by the fact that I cannot touch the oil pressure line leaving the engine, however I can touch and hold in my hand the return line and fill cap without issue when the engine oil is at 205*.

What cooler and fans are you using? Also how was this mounted?

I see this as a simple kit. .75 quart a minute sounds like pretty good flow. Hard to believe you are not seeing lower oil temps?

 

[NCJL]

What cooler and fans are you using? Also how was this mounted?

I see this as a simple kit. .75 quart a minute sounds like pretty good flow. Hard to believe you are not seeing lower oil temps?

Derale cooler with fan mounted to underside of truck bed in spare tire area. Cut out tire carrier metal plates. Pics are included a few pages back.

The .75 is at 25 PSI. Cruising RPM flow would be a little more. Maybe a quart plus.

I was also surprised by the temp. However I’m very happy to see peek oil temps at 235*. Any more and I may get into a whole other set of problems.

 

[pmpmstrb]

First off sorry it's a JLU. I won't have my JTRD for a couple weeks. It just landed in SLC and is on its way to Kent at Peterson. About to head out for the weekend and put the new cooler to the test. For the guys in Arizona we are heading up to Woods Canyon Lake. It's about 120 miles one way and has multiple 6% grades. Temp is currently 90* @ 9am with a forecasted high of 105*. I'll do my best to take pictures of the gauges as we go. This is the same path that caused my derate last time. I won't be able to update until we get back Monday. Have a great weekend everyone.

 

[CrazyCooter]

First off sorry it's a JLU. I won't have my JTRD for a couple weeks. It just landed in SLC and is on its way to Kent at Peterson. About to head out for the weekend and put the new cooler to the test. For the guys in Arizona we are heading up to Woods Canyon Lake. It's about 120 miles one way and has multiple 6% grades. Temp is currently 90* @ 9am with a forecasted high of 105*. I'll do my best to take pictures of the gauges as we go. This is the same path that caused my derate last time. I won't be able to update until we get back Monday. Have a great weekend everyone.

Don't let the Geo Metro's run you off the road for impeding traffic on the hills!

 

[Teqsand]

Took wife's JLURD to LAX from the high desert, on the way back, across the Edwards lakebed, it was 109⁰ outside and i couldn't do over 50mph.... lasted about 15 mins then returned to normal...
Noticed batt was not the normal over 13, until the power returned then it went over 13

 

[22EcoDs]

Took wife's JLURD to LAX from the high desert, on the way back, across the Edwards lakebed, it was 109⁰ outside and i couldn't do over 50mph.... lasted about 15 mins then returned to normal...
Noticed batt was not the normal over 13, until the power returned then it went over 13

There's nothing wrong with those temps on. Hot day tho. Wonder why it derated.

 

[Rusty PW]

There's nothing wrong with those temps on. Hot day tho. Wonder why it derated.

Air inlet temps?

 

[Teqsand]

There's nothing wrong with those temps on. Hot day tho. Wonder why it derated.

No clue.... the dash pic was after the power returned....

 

[22EcoDs]

Air inlet temps?

I would think hot iat correlates to hotter oil because of the egr heating up too but I suppose it would cut boost and fuel due to lower air density at the hotter temps ? Making a true cold air intake would test this.

 

[Glad_he_ate]

I think these intakes bring in quite a bit of air from the grill. Not gunna get much colder then that lol. I know some comes from the hood section but still pulling a lot from the front.

I would think hot iat correlates to hotter oil because of the egr heating up too but I suppose it would cut boost and fuel due to lower air density at the hotter temps ? Making a true cold air intake would test this.

 

[pmpmstrb]

Short version is that I am extremely happy with how everything performed. With the fan OFF my oil temp was usually 10*-15* higher than the coolant temp. With the fan ON my oil temp was at or below the coolant temp. Driving on regular roads (flat with normal ups and downs, etc) the oil and coolant never got over 230* driving at 75mph. They were usually closer to 215*-220*. I had a long, windy stretch at 6% grade that had my coolant at 237* and oil at 241* driving at 60-65mph with AC on. I had numerous 6% grades and once I got to the top the temps came down rapidly, whereas before it took much longer. I did notice that anything over 235* coolant temp caused the gauge on the dash to start moving. So at 237* it moved up to just under the halfway mark. I'll post a picture of my temps from when I reached the top of the long 6% grade. I would like to get the coolant temps down a little bit, even if it is only a few degrees. I'll probably try some water wetter and removing the foam inserts from around the motor. All in all I'm happy with how it went.

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