Replacement ECU installed, no issue with SRS (that I could see) and had the ABS light flash and ding. Pulled the ABS fuse and now just have pretty lights on the dash. Took it for a spin around the block and all is good from a running stand point. Will be creating a bench setup next to eliminate the truck and get a good HPT file generated.

Adding link to the HPT lessons learned thread to link the two threads...
HP Tuners Lessons Learned 4.7 engine - DodgeForum.com

 

breather mod in progress, one side is one cut and then ready to go. Quick and relatively cheap... maybe $50~60 in parts. (the USA made clamps were $3 ea) looking to get oil vapor out of the intake... will experiment with it and see how it does. if good then maybe will do a catch can.

 

I have racked up close to 200 miles on the hiway since the last fillup, will be filling up this afternoon while grabbing an oil filter. This tank has been good weather wise, may not be that way soon though as heavy rains are arriving soon. I have the breather mod ready to go, going to pop that on the end of the breather hose to the air box and plug the air box opening. Will run 200ish miles like that and see if there is any change noted. I expect none. Rains should blow out by tomorrow and it should be rain/wind free for the next several days.

 

208.x miles @ 15.468 mpg. Rain & heavy winds 1 day of 2 & had a nasty hill climb yesterday. Motor sounded like a jet engine it was so loud.. This was the tank to measure the DTCM. sure does look like the JTCM did better. (exception being the weather and hill sooo....)

Installed the breather mod experiment, added breather at the end of the hose attached to the air box, capped the airbox. Will see how this does and may move 2 vents to each head port.

 

Feedback on breather mod...

I dont have high hopes for any mpg changes, 20~25 mph winds here. But an eye brow was raised... on the way out to the hiway there is a mile-ish long hill that I climb while heading into town, on that hill the trans kept wanting to upshift into 4th whereas prior it would always hold 3rd. My interpretation of that is there is less load on the motor thus less throttle input which is at a tipping point for the upshift. Huh... Ooookay... So I hit the bridge and now see the cross winds, 2 air socks on the bridge are at full extension (18 mph wind speeds to get full extension IIRC). Next hill, a 3+ mile one (I think I said it was 2.8???)... as with every change I attempt to keep it from down shifting and see how much acceleration I can get out of it. To my surprise it is the best yet, However... be reminded that this is week 2 since going back to the DTCM & rpms are ~300 rpms higher, which made a difference... but not to this extent.

To make it clear, the goal of keeping it in high gear and accelerating is to gauge how good or bad the change effected performance at the cruising rpms. I could easily let it downshift and motor on up the hill at higher speeds.

This appears to be an unexpected benefit, zero vacuum on the breathers now and OEM breathers still in place. If I end up wanting to keep a modified breather setup then the 1st thought that comes to mind is to do an updated PCV setup and look at using the PCV location on the fill tube as an oil return. The ram has a setup on the valve cover that may be a good fit to leverage and i think I may have my original still in a box.

'03-'05 5.9L Dodge Cummins 3957987 Crankcase Breather Filter (genosgarage.com)

 

Observation on breather mod... drove in with the gauges on the dash this morning and noticed CT's climbing up to 210. Prior to the mod it held 204ish pretty well. I'm guessing the lack of vacuum on the breathers now is allowing more heat to sit at the heads. Interesting... with this new knowledge (if accurate) that would mean with the 180* stat it should be running up there around 190~195.


edit: A thought just occurred... it might be possible to fine tune the vacuum draw off the air box with a valve and control that flow better. how that could be used is yet to be determined...

 

Your honesty is always refreshing with regards to your findings. Seen to many posts where people fudge numbers to support their arguments.

What is your goal with running it cooler?

Consider this. My truck is still going strong with 330K. It ran probably over 100K mi with a broken electric fan, much of sitting in daily summer traffic jams and the needle climbing a bit past halfway. If it was fine running a bit hotter than intended, I don't see a need to run it cooler than the engineers designed. Constantly running below 212* (the temp at which water boils) is a recipe for sludge. Every trip - long or short, will have the effects of a short trip.

We know the 4.7 has smaller passages, oil galleys and such, so it will sludge faster than say... a 5.9. You've got a thread about the snot collecting in the oil fill cone and I've seen it under the valve covers, yet you want to go cooler. What about the unseen parts of your engine? Most motor oils, esp quality synthetics will not see the onset of thermal breakdown till over 275* and much higher, so the oil is fine at higher temps.

So my original question again....exactly what do you hope to accomplish, longevity? I've already got that and then some.

PS: I've been saying this for a long time. https://dodgeforum.com/forum/2nd-gen...hermostat.html

 

The answer is generally in the data, from my point of view, there is no value in fudging numbers to support any argument. I'll always post up results, good or bad.

Running it cooler = Reduced risk, reduced MTBF of known parts that have failed on other 4.7 engines (valve seats, head gaskets, and then there is the toll on peripheral bearings, wiring etc) . The hotter you run it, the shorter the life. Engineers did not design anything into this motor to make it run at 212*, they run it hot for FE to meet government requirements for manufacturers. They designed in a 195* t-stat yet it runs at 205*, (at least on mine) cooling system cannot keep up with it (or my fan clutch is actually dead). Been around the block enough to know that the 10~15* temp reduction to get my engine running where I want it is not going to cause any additional sludge. The hotter the oil temp, the higher the oxidation rate, sludge forms with oil vapor and oxygen... aaannnd guess what I just did... THANK YOU!! seriously... challenge is good.

Also, the engine does not need to run at 212* to burn off moisture, the moisture will start to vaporize at a lower temp. Not sure what that temp is, never dove into it. this makes me wonder what the vapor is in this shot... oil or water...

 

I forgot why you would change to the 180 thermostat as well.....

Running a hotter engine is better for fuel economy..... and like Dodgevity mentions it's designed for it.

The heads will hold up, no problems till you reach at least 220 or more, so running lower has only downsides in my book.....

The horror story's of bad heads and all i don't believe, if you maintain the engine, which means air, cooling, oil, and all the rest of the truck, you should have no problems.

You could built a 1000hp engine, but when you don't modify you're brakes and run skinny bald tires, you are not gonna last.

Maintenance covers the whole vehicle, not just one part of it, so i don't see the need on a standard daily driver to change a thermostat to operate the engine at a lower coolant temp it was designed for and doesn't improve anything.

Just my 2 cents, don't wanna offend you or anyone, you're all free to do whatever you think is best, but i do like to hear again what's the argument for running a cooler thermostat.

And off course we follow you on the changes, better or worse to see if we could benefit from you're outcome

 

The oil runs hotter than the coolant in any event. Normally rather north of 200 degrees. (when the engine is at operating temp anyway.....) So, boiling the water out of it isn't really related to coolant temp.