Low RPM engine Lug rabbit hole

[Rp930]

My truck does the same thing. Vehicle speed dropping, driver is inputting more throttle to the vehicle, and while continuing to lose speed the whole truck vibrates because it is in too high of a gear. It's pretty much the definition of lugging. Typically, this occurs when not driving like a madman, for me when trying to go about 10-15 mph in the neighborhood (up a slight hill) or cruising around a campground or trailhead. It is not normal vehicle behavior unless you have a Ranger, then it is just considered a "truck thing". You can remedy the improper shift points by installing a tune. Chances are if you are experiencing the lugging you probably keep things easy on the throttle most of the time. If this is the case, another benefit of the tune is you will increase your gas mileage. My theory on this is that I don't have to put the pedal to the floor to get the truck to shift where it should be. It really does make a world of difference. I recently removed the tune on my truck as I'm going to follow the best advice in this thread and I'm getting rid of this truck. Once I removed the tune, shifting returned how it was and the lugging returned. I kept the tuner plugged in so that I could monitor RPMs and temperatures and noticed when it is happening the truck is down around 1100 RPMs. Just some productive feedback from someone who actually owns and drives the same truck as you.

The UAW strike has my replacement vehicle delayed for an undetermined amount of time, so I have been hesitant to start selling all the stuff on my truck. But, keep an eye on the marketplace if you are interested in a Ford Performance Tuner.

Your FP tuner will only work with your truck as far as I know.

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[puda]

Your FP tuner will only work with your truck as far as I know.

I didn't really think about that, it appears to be true. I'll have to see if I can get FPP to "unlock" it.

 

[Rp930]

I didn't really think about that, it appears to be true. I'll have to see if I can get FPP to "unlock" it.

I think it’s one license for one VIN

 

[ControlNode]

I get it, I've read some of your posts, you come across as more educated than others and use your info in that way. I'm sure its not just anecdotal and personal opinions, you seem to have a background in the know.
So help educate me, is there hard data available from the computer to determine if 1500rpm on the highway cruising along is showing signs of pre-ignition and lugging?
If there is, and it's not happening at a highway cruise speed, when is it happening? how heavy of a load do i need to pull to enter pre-ignition and the detrimental effects it causes?
Is some of the pre-ignition concerns caused by the driver themselves? such as puttering in traffic in 10th gear, then flooring it? does that up the load to lugging territory until it finds the right gear and increases your RPM?
I'm only asking because I have lots of manual experience, and I never see my Ranger act like it's lugging under any of my current driving requirements. I could easily make my manuals lug if I wanted to.
If I am puttering in town in a high gear, slow speed low RPM situation, its reacting just fine, even when I accelerate normally, it drops gears quickly and accordingly. I'd really like to find out for fact that my in town driving is creating pre-ignition. If it is, then I might alter my driving. But I'm not going to ask my engine to do 25% more piston strokes, and use more fuel over its lifetime unless I have to.

I'm not claiming preignition. But, the much older man, that had been a mechanic about is long as I'd been live at that time, that helped me swap in a new engine into my 84 Civic (my first 4cyl and first manual that I bought it cheap with a bad engine) said looking at the bearing damage on the rod bearings of the engine we pulled said it looked like too much low rpm driving, or too low for the throttle it was lower RPMs. The car was a 5spd so pure manual user selected gears. He said that under 2k the oil pump is pumping, but the pressure is normally lower than the relief valve's release point. Add the slow rpm to that and even when normal ignition happens it's more likely to smash the oil out from the bearings on the rod to the cylinder that just fired enough to allow metal to metal. He told me that maintaining 2k helps by having the oil closer to full pressure, if not full pressure, and because of the increased crank rpm it's harder to oil the oil out since more is being drawn in faster due to the increased bearing surface speeds. The important part is maintaining that fluid bearing between the metal ones. His guidance was that with a 4 cylinder to maintain 2k driving and if you need to get on it, be over 3k if you can. Following that I've had no issues with my 4 cylinders. I know the newer engine may have higher flow oil pump or even variable oil pressure controls, but it's a habit and it just feels safer to me.

 

[MarioCart]

I'm not claiming preignition. But, the much older man, that had been a mechanic about is long as I'd been live at that time, that helped me swap in a new engine into my 84 Civic (my first 4cyl and first manual that I bought it cheap with a bad engine) said looking at the bearing damage on the rod bearings of the engine we pulled said it looked like too much low rpm driving, or too low for the throttle it was lower RPMs. The car was a 5spd so pure manual user selected gears. He said that under 2k the oil pump is pumping, but the pressure is normally lower than the relief valve's release point. Add the slow rpm to that and even when normal ignition happens it's more likely to smash the oil out from the bearings on the rod to the cylinder that just fired enough to allow metal to metal. He told me that maintaining 2k helps by having the oil closer to full pressure, if not full pressure, and because of the increased crank rpm it's harder to oil the oil out since more is being drawn in faster due to the increased bearing surface speeds. The important part is maintaining that fluid bearing between the metal ones. His guidance was that with a 4 cylinder to maintain 2k driving and if you need to get on it, be over 3k if you can. Following that I've had no issues with my 4 cylinders. I know the newer engine may have higher flow oil pump or even variable oil pressure controls, but it's a habit and it just feels safer to me.

that makes sense, i can understand that happening.
i'm hoping we have higher oil pressures and better oils than the mid 80's

 

[airline tech]

Using 2 separate manuals, this is what I found.
2 different sources

Oil Pressure: Hot
@ 1500 RPM - 28-38 PSI -- Source 1
and
@2000 RPM 29-60 PSI --- Source 2

The Ranger uses a Variable Press Solenoid, to control the Oil Pump Pressure.

On a side note:
The Ranger also has VCT - Variable Camshaft Timing, this alone plays a factor in the Low RPM Torque

 

[VAMike]

The ranger most certainly lugs once the differential pressure sensor dies. On the plus side it's easy to fix, on the minus side Ford is clueless and the dealers haven't been told so they'll just reset the transmission to get rid of you.

 

[Tony Robyn]

If you want to eliminate the transmission bogging and gear hunter press tow and then press the minus symbol on the shifter and lock out gears 9 & 10.

When I had my Ranger I actually increased my MPG doing this (I live in an area with lots of graded hills.

I live in an area of mildly rolling hills, so would typically have hard transmission shifts from low gear at 55 mph speeds on grades. Got to the point where I could anticipate the slam and it made driving so aggravating. I actually lock out 8, 9 and 10 now and haven’t had a problem since. Seems silly to manage the transmission this way on a $40,000 piece of equipment, but it works.

 

[Motorpsychology]

. I know the newer engine may have higher flow oil pump or even variable oil pressure controls, but it's a habit and it just feels safer to me.

The 2.3L Ecoboost 4 is also an udersquare design: bore smaller than stroke, like the 2.0L Ford 8N tractor. That engine had a rated horsepower (at PTO) of 92 @ 2000 rpm and torque of 92 lb ft @ 1500 rpm Undersquare engines are designed for more and broader torque at lower rpm, sacrificing hp at higher rpm.

That's the science. But I, too, drive around town in Trailer Tow because I can't stand the booming drone in 7th/30mph.

 

[2021Ranger]

The Honda was most likely detonating, that alone will take out the rod bearing..

 

[Msfitoy]

I live in an area of mildly rolling hills, so would typically have hard transmission shifts from low gear at 55 mph speeds on grades. Got to the point where I could anticipate the slam and it made driving so aggravating. I actually lock out 8, 9 and 10 now and haven’t had a problem since. Seems silly to manage the transmission this way on a $40,000 piece of equipment, but it works.

Firm down shifts or slam/bang down shifts? If latter, you have bigger issues pending...locking gears out won't fix it...

 

[Shawn_Mc]

The low speed chug comes from the idiotic transmission shift strategy, up-shifting and locking the converter at obscenely low rpm and speed. Switching to shorter tires will just cause the same scenario but at lower actual speeds. If you change the TCM for the shorter tires, it'll still do it because you're not changing the shift strategy.

The way to fix this is to re-tune the TCM to NOT lock the torque converter until about 45-50mph, minimum. But I dont think that's possible with a Forscan. If it is, I dearly need this information, because that will be the very first change I make.

Sport mode and Tow mode hang onto the shifts a little longer, but it still locks the converter at way too low of a speed and keeps it locked. And worse yet, after punching it for whatever reason, it then hangs onto the lower gear, even after letting off on the throttle. Which is also stupid.

 

[Tony Robyn]

Firm down shifts or slam/bang down shifts? If latter, you have bigger issues pending...locking gears out won't fix it...

I would say firm as in solid, not sure I would classify them as slam. Hope not anyway and if so, within my powertrain coverage

 

[yamahaSHO]

I couldn't stand the low RPM lugging, so the first thing I did was pull out my MPVI2+ and tune the transmission. Been pretty happy with how it drives now. I haven't even touched the engine tuning, just make it drive better.

 

[Jedadiah]

Is the lugging a bigger problem if you install bigger tires? Mine likes getting to 1:1 (7th) kind of early, but very little pedal gets it where I want it to go. I'm in the minority: 2wd--not upsizing--for the class though. It sucks it takes a tune to prevent what Ford could clearly could anticipate. I guess T/H and S are an out, but...

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