flywheel weight

[deadbeat]

has anybody ever lost a weight off the flywheel? How would this cause a vehicle to act. I have a vibration at low rpms that smooths out in higher rpms. But it even vibrates sitting still. It seems as though something is out of balance and I have changed the harmonic balancer. It is a 90 4x4 ranger with a mazda 5 speed tranny. Just curious what you guys think.

 

[MAKG]

This sounds much, much, much more likely to just be an ignition miss.

Simple stuff first.

 

[AllanD]

The 4.0 flywheel is "neutral balanced" and thus has no "weights"
to fall off.

the "rim" of the flywheel is drilled to balance it.

the clutch pressure plate ("clutch cover") MAY have a welded on weight
for balancing

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[deadbeat]

it has a 2.9 btw, but i would agree with ignition miss but i have tuned the motor, checked time, and the motor runs quite well. It just has a "shaking" that vibrates when you are at 1200 to 1800 rpms. I have timed the motor to 12 degrees and had it at 10 with no change. The vaccuum i believe was at 17 pounds on the gauge and i have checked every line and sprayed carb cleaner all around the intake. I even thought the vibration might be caused by mounts so I changed all those to. I changed the tps and set it to .95 with a volt meter. I really just dont know what to do now. Thought maybe it was a weight or balance issue since the problem started by hitting a large hole in the road at 55 mph. Also, would the clutch weight you are talking about AllenD have an effect on the truck sitting still in neutral? How would a cracked flywheel act? It just really feels like something is out of balance, and btw, it doesnt do this at dead idle, it only does it when you first touch the gas, but i have changed everything electrical and in the ignition, the truck is not missing.

 

[MAKG]

Waitaminit.....

1200 to 1800 RPM on a 2.9L? The engine should NEVER be running at that, except at cold idle. You're lugging the engine if you EVER do that under power.

 

[deadbeat]

I live in Kentucky and a lot of the small side roads you cruise out in 3rd gear and do lug, but the fact is it never did this until i hit the bump, now it does, and something is wrong. Im not pulling and I dont have large tires, just notice it when driving along small roads.

 

[MAKG]

It doesn't matter if you live on Mars. 1200 to 1800 RPM on a 2.9L is *B* *A* *D*.

Cruise at at least 2000 RPM on a 2.9L. 1200 RPM is barely off idle.

I drove a 2.9L on small mountain roads myself for several years. It makes the difference between a massive POS and a pretty good truck.

You have a stick. This is driver error.

 

[cocoasranger]

MAKG, On the 2.9L, how high an rpm can you go to between shifts on a regular basis without screwing anything up? Also, I am using mid grade 89 octane. Is regular 87 better, the same, or worse to use? The Ranger is stock with 10 degree timing.

 

[MAKG]

The redline is 5500 RPM. Yes, it will do that.

The correct octane to use is the lowest that doesn't detonate. That's what octane is for. It should work fine with 87, but if it doesn't, there is something wrong. It may not be easily repairable (e.g., leaky intake valve guides).

 

[deadbeat]

Yes, but the truck even does this sitting still, something is wrong. I never said I always drive it at these rpms, but i often hit them. For that matter, if you are cruising down the highway in a automatic tranny at 55 on flat ground, what rpms is it running, my guess in OD it isnt running 2k. Does that mean all automatic rangers run bad? My truck has a problem, I just want to figure that problem out, it is not due to the driver.

 

[AllanD]

For practical purposes revving a 2.9 above 5100-5200 on a 1-2 upshift is pointless

4900-5000 2-3
4800-4900 3-4
Shift into 5th when you are going fast enough to suit you, because
for ANY purpose you aren't going to go materially faster in 5th than
you can do in 4th.

It usually takes 4.10 gears to GET to 4600rpm in 4th.

If you are seeing higher numbers on your 2.9's tach, replace it.

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