Why is Lugging Engine Bad?

[Tinton]

You're noobs. The crank is the strongest part of the engine? Go run your engine out of oil and then see what your bearings do .

[Bawked]

i went down to .5 quartz and the bloody engine still lived stupid toyota bloody engines....

[RITmusic2k]

i went down to .5 quartz

That reads really weird. Like you partially crystallized your crankshaft or something.

BUt man, I know what you mean about those Toyota engines refusing to die...

My girlfriend tore a 4" wide gash out of the bottom of her Corolla's oilpan and managed to drive the car ten minutes back to her apartment on a dry engine. The car started the next morning. She'd still own it today, but her mechanic offered her $500 for the car as-is so he could fix it and resell it himself.

[handydandy]

if you are starting in first and you dont add enough gas, making the engine fall under the idle rpm and sputter (but saving it from stalling) count as lugging? i do this frequently when i change my shoes (weird i know)...and i can hear/feel the engine almost die...
is this lugging? or bad?

i have acura tsx btw.

[RITmusic2k]

No, that's "almost stalling". Lugging would be flooring it with the clutch fully engaged and the engine speed relatively low (say between 1000 and 1300 rpms for example). And the higher gear you do this in, the worse it is.

So, if you were cruising in 5th gear and you coasted down until the engine speed was at 1100rpm, then floored the gas to speed back up, you'd be lugging the engine until it got up to a more comfortable speed.

[theholycow]

Lugging would be flooring it with the clutch fully engaged and the engine speed relatively low (say between 1000 and 1300 rpms for example). And the higher gear you do this in, the worse it is.

So, if you were cruising in 5th gear and you coasted down until the engine speed was at 1100rpm, then floored the gas to speed back up, you'd be lugging the engine until it got up to a more comfortable speed.

Actually, no. See Prodigal Son's post on the first page of this thread:
viewtopic.php?p=91271#p91271
In a very old car those would be appropriate instructions to cause lugging, but lugging is predetonation caused by those conditions. Modern cars are protected against it with variable ignition timing and knock sensors.

[RITmusic2k]

Back on pg.3 of this thread I addressed that. There is a spectrum of opinions on what constitutes lugging. The less severe definition (which is my side) is still severe enough to be addressed.

[ClutchFork]

Lugging engine is like beating on your main bearings with a hammer, well not quite the same, but it does pound them in a way they were not designed to be run. Also pounds the rod bearings, scuffs the cylinder walls, and all sorts of other bad things happen. Lug all the time and surely you will cut engine live in half, quarter, or worse.

[Shadow]

[ClutchFork]

I couldn't help myself

[tankinbeans]

It does bring more awareness to the thread. I know I'd never seen it before because it was old when I got here.

[Shadow]

It does bring more awareness to the thread. I know I'd never seen it before because it was old when I got here.

Yeah, that's fine. The thread predates me too, so it's nice to see stuff that was discussed long ago. But at the same time, there have been quite a few more recent discussions about engine lugging and exactly what it is and how it's harmful. In fact, I've had more than one debate with Cow about that very subject. He feels that lugging doesn't happen on a modern engine and I don't agree with him at all.

[ClutchFork]

You're noobs. The crank is the strongest part of the engine? Go run your engine out of oil and then see what your bearings do .

Yeah, the crank is very strong, especially if it is forged, but the bearings have a very thin and delicate surfacing which if scrubbed or hammered off will soon cause nasty scoring of the main bearing journal surface on the crank.

People sometimes run an engine (typically an inline six) without oil until it dies and then proclaim it lasted half an hour or whateve it is, but if they shut it down partway though that process or even after a couple minutes of running without oil and try to save it by refilling it and going on their merry way, I would bet that enginew will have much lower oil pressure than it had to begin with.

My F150 saw a lot of grit from a construciton zone for a 3000 mile oil change interval where the pcv hose fell off and the engine was sucking raw air. Oil analysis showed lead at 476 ppm! That is right off of the main bearing shells. After fixing the hose, the next couple oil changes showed lead at 126 ppm, then about 66. But the end result was my oil pressure suffered a drop of about 8 psi from 44 to 36 on the hot at 2000 rpm. I attribute that directly to the grit treatment.

[bk7794]

Lugging engine is like beating on your main bearings with a hammer, well not quite the same, but it does pound them in a way they were not designed to be run. Also pounds the rod bearings, scuffs the cylinder walls, and all sorts of other bad things happen. Lug all the time and surely you will cut engine live in half, quarter, or worse.

I wonder what is considered lugging the engine. I guess I'd rather slip the clutch and replace that sooner than to replace the engine.

Your topic brings to mind this question in my head. Impact or a torque wrench for the main pulley bolt. New thread time!

[Rope-Pusher]

I wonder what is considered lugging the engine.

Fickset