First time posting on this site, i have to say this site is amazing always have found stuff that has helped me. Well im hoping someone could explain whats houng on with my truck. First and foremost the truck is a 1999 2wd 5 speed 3500 2nd gen cummins and it has a cold air intake and a intake horn, edge ez, 50hp injectors, new H. O vp44. The truck has 307k miles and runs amazing and has no issues. But when im driving on the highway at a steady speed around 80mph the sound in the engine bay will change every 15-20 seconds it is most deffinetly the sound of combustion changing and or the injection timing changing. The truck will have the typical knocky 24v clatter that sounds kind of like a machine gun but every 15-20 seconds that knocky sound will totally disappear and the engine sounds so smooth at this point, after about 5 second, sometimes a little longer it goes back to the klattery machine gun sound for another 15-20 seconds and then back to the smooth sound. It is most deffinetly the sound of combustion and not like valves or anything like that im 100% sure of that. Its like the ignition timing is changing and changes the engine sound. Exhaust note doesnt change its all under hood noise . Has anyone ever seen this or have a clue at how and why it does this? I wish i had a way to view the timing commands in real time and see if their is a correlation in timing changing and the sound changing. It would be nice to find a way to make it have that smooth quiet tone all the time while on the high way it would deffinetly keep some decibels off  

Good luck man, that **** sucks cancer always goes after the good ones, my mum has multiple myeloma (blood cancer) i wouldnt wish it on anyone. And i figured out that 0-3 infact has no change from my tune changes, i was over here thinking that it did at first🤦 then tried out the other levels and went wtf im an idiot trying all these changes and thinking it was doing something when it didnt

@daav544, here is a tire size comparison for the tire you currently have and the future tires you will install later.

 

 

Below is a sample of how these different tires sizes will have a minor effect on road speed and engine torque put to the ground.

 

The first chart reflects your bald 215/85 R16 tires (30.4" diameter)

The second chart reflects the tire you are going to purchase - 235/85 R16 (31.7" diameter)

 

The numbers high-lighted in yellow represent the direct gear (1:1 ratio) for each transmission.

 

I can change the numbers in blue to reflect different engine rpms, different axle ratios, and different tire sizes.

 

- John

 

 

Check out tacomaworld com they also have a great tire size comparison calculator. It shows you the speed differences at any speed and the percent difference in size the tires are from each other. Thats how i ended up putting 245 75 16 on my front rims they were only like .8 of an in larger than the 215s i had on the rear(trucks 2wd) but again im not fully understanding the reasoning behind why the final ratio needs to be between 3.55 and 3.73 to get a tune made?

EGTs. Lower than 3.55 ratio no matter what I do the EGTs will be high. Then everything else will run hot. You won't be able to run high timing because you'll need constant retard for boost. Remember Trans Temp is my Engine Oil temp. You'll see every stays fairly cool even running 200°F thermostat. Another to note 30 degrees of timing is the max of the VP44.

 

3.69:1 ratio at 80 MPH (I84 heading to Boise)

 

3.69:1 ratio at 65 MPH (US 95 heading between Weiser and Payette ID)

 

3.69:1 ratio at 55 MPH (Between New Meadows and Council ID)

 

Now look at the ECO. Nice high numbers.

 

I know I don't display boost pressure being I know my MAP sensor has some error. 

 

Stock HX35W turbo (54/60/12) with 7x0.010 injectors (+150 HP popped at 320 bar)

55 MPH = 0 PSI Boost

65 MPH = 2 PSI Boost

80 MPH = 7 PSI Boost

 

Again poor finally ratio will require much more retard than me which would build boost and help control EGTs but you'll lose some of the power stroke to build boost wasting expanding gases to spin a turbo.

 

Now the only pic that is not in cruise mode is 80 MPH but I've reduced the amount of retard based on load which allowed me to keep the gains.

Edited May 2, 2024May 2 by Mopar1973Man

Mike, You and I spoke on the phone a month or so ago about trying to get my eco tune dialed in. Regardless of where I'm at with timing/engine load/boost, my oil temp is always 7 - 10 degrees hotter than coolant temp. I know you said advanced timing causes this but I'm running around 19-20 degrees timing, sub 5 psi boost, engine loads in the 20-25% range at 65 - 70 mph, 1800 - 2000 rpm. Is it just impossible to swap those temps numbers in a rig with an automatic transmission/parasitic drag?

@Mopar1973Man question regarding coolant temps just eana know if this is normal or not. Towing my 4k pound camper on flat ground steady speed noticed my coolant temp would fluctuate from 194 to 204 it would take about 20-30 seconds to go from 194 to 204 then back to 194 and do it all over again is that normal

Thermostat is failing and sticking. Don't buy a Cummins which is not designed or built by Cummins. Hence I buy NAPA thermostats.

No **** huh? So what does you coolant temp reading do while cruising down the highway at like a steady 70-80 mph? Or what should it be doing, i know that over a certain temp it reads -40 so with your higher temp thermostat you probably dont get to see the actual temp to often. Is there any way to fix that? Obviously the dash reads up to 240 so why cant the adrenaline?

I'll tip 210°F at 80 MPH. Typically at 65 MPH is floating at 205°F. No, there is no way to fix because it a Cummins software bug in the ECM. A live data tool will see full range of coolant temperature.

Now how come the dash will read up to 240 though? It be cool to tap into that gauges wiring and somehow wire in a little digital temp gauge

Might end up buying one of these so i have an accurate temp reading at all times

Also you dont think it could be a head gasket do you? I still have stock head bolts and stock head gasket 312k miles i get on it here and there but i really do feel that i baby this thing. When its piping hot i can get out of the truck and take the radiator cap off and it barely relives any pressure a little coolant will seep out as a hot engine typically would when taking the cap off. My old duramax i had that had bad head gaskets would build radiator pressure almost instantly and if you took the cap off even after starting the engine cold after 10 seconds if you took the cap off it would geyser out of the radiator like a dam fire hose. So in that sense i feel like im good compared to that truck. Ive heard of people re torqueing stock bolts with good results and also heard of people breaking bolts doing that. I wana get the power driven diesel head bolt kit eventually and change them one by one but i wana be sure that im good HG wise. Im guna change the thermostat this weekend and see what happens.

Cummins CanBus is limited because of the Cummins ECM software bug. Now Dodge CCD network over the OBDII port will show correct because the software does not have that bug. Yes any OBDII live data tool shows correct values but sadly Quadzilla never show any temperature above 204°F.

Yea thats a bummer we dont get to see the full temp range. So back to the slight fluctuations, you dont think it could be HG related do you? Like i said in my previous rant, even when this truck is piping hot i can take the radiator cap off with only slight pressure relife. Truck doesnt eat coolant. I had a duramax with bad HG and it would build pressure within 10 seconds of starting. Ive started it and taken the rad cap off withing 20 seconds of starting and it sprayed out like a fire hose. So compared to that truck i feel like im good. I baby this truck i do get on it sometimes but for thr most part i drive like a grandpa. 312k miles with stock HG and stock head bolts just worries me though id like to replace the head bolts one by one with power driven diesels head bolt kit but want to be sure my HG is good.

Simple test. On a cold engine hook up a coolant tester pump it up to 16 to 18 PSI and wait. If it's leaking out a puddle should form on the floor as pressure drops. Be aware my first head gasket blew out in the rear of the head due to weak head bolts and head curl which is normal around 300k miles.

Now wouldnt i see a leak from just normal coolant pressure from just having the truck idle or driving like i said before this thing doesnt eat a drop of coolant. And 90 percent of the time im babying the thing but have gotten on it a few times. Also if it is still good whats your opinion on replacing head bolts one at a time? And studs or good bolts like power driven diesels bolt kit. Also heard of people buying new stock bolts and torquing them to like 130-140ftlbs with good results holding up to like 50psi. I dont plan on pushing this truck really any farther than im at (7x0.010) injectors,stock turbo)

No. It typically dries up before it hots the ground. Like mine did it only leaked and puddled on the floor with a coolant system tester. Normal driving it would have the smell but nothing on the ground.

If you don't have a coolant system pressure tester of your own, you can "rent" one from Oreilly auto parts store.  You'll have to pay for it first then you have 2 days to use it and bring it back for a full refund.  I've "rented" several of their tools over the years with no problems. 

https://www.oreillyauto.com/detail/c/evertough/tools---equipment/rental-tools/air-conditioning---cooling-rental-tools/12095d53bcad/rental-tools-evertough-radiator-and-cap-test-kit/ren1/67085

Ahh i see,  well if im good would it be fine to do studs or bolts one by one, i really hope its fine and im just worrying i do not feel like pulling the head loll done it once on a 6.7 dont wana relive muscling that tank of a head on and off loll. And to @IBMobile ive rented a few things from them i might do that this weekend when im fixing my AC. Its almost like one of those if i dont check it will be fine if i do it wont kind of dread lol. Atleast its not a duramax, thankfully these things are relatively easy to do 

Soo im reviving this post because this issue came back. The engine tone changes while driving it's the timing jumping back and forth it went away when I installed the adrenaline after I switched from the edge ez timing will jump from 16 to 21 and back while cruising at 2000 rpm, only thing I did yesterday was change battery terminal ends here are pictures of the tow tune I've been driving on

I thought it may have something to do with the grid heater since at the same time i replaced my battery cable ends i disconnected the main lead for the grid heater, i have since re connected it though. Just completely stumped as to why it would be doing this it's almost as if it's going from the adrenaline tune back to stock and back to the adrenaline tune. Before when I would cruise at 2000 rpm it would always stay right around 16-17 degrees of timing on that tune. I was reaching around the can bus area yesterday as well trying to get the grid heater relay block or whatever that is bolted back to the fender well as it was just hanging there from the previous owner so I didn't know if I messed with the can bus by accident but it was plugged in and seemed fine. Also when i disconnect the main plug from the adrenaline and plug it back in I can hear a little click noise, I assume this is normal and it's just doing its thing