Jeep Shake

[tjkobs7926]

Hey,

I just discovered today that when my Liberty reaches 4,000RPM the car shakes and the engine cannot go any higher?

Anyone experience this?

THANKS

 

[kjpilot]

4000 RPM regardless of vehicle velocity? Will it shake with the transmission in neutral? how about park? If you can find a safe place, bring the KJ up to a decent speed (MPH), then place the transmission in neutral & rev the engine to 4000 RPM. Try the same thing while at a stand still.

We're trying to isolate the engine, transmission, & drive train.

 

[Jeger]

It is probably the rev limiter kicking in. I think it kicks in before redline if you are in just revving the engine in park or neutral. I have a CRD so Im not sure what the redline is on a gasser, but our other cars will do what you describe if they arent in gear.

 

[hyde]

Are you revving while on park or neutral?
if so it is preventitive so that rpm doesnt go redline and start messing up your engine.

try flooring it when you are dirving, it will always go up to redline every time.

 

[hyde]

wow almost at the same time
redline starts at 5700 on gas kj, and rpm on dash is up to 7k

on crd it is much lower.

 

[kjpilot]

It is probably the rev limiter kicking in.

Perhaps. the rev limiter cuts fuel when over the red line, then once the tach drops below red line it allows fuel to flow. This results in more of a bucking engine than a rough engine.

 

[tjkobs7926]

Was reving it in park and this is when it was discovered. I tried again in Neutral and it still continued. I will try later today while the car is moving and I will put the peddle to the floor and see what happens.

THANKS for the help

 

[tjkj2002]

My '02 will rev to redline in park and neutral,must be different for newer models.My '96 Tauras did the same thing,the computer would limit the rpm's to 3750 in park or neutral.It's just to protect your engine,in top gear at that same rpm is also the governed top speed for the KJ.

 

[hyde]

Was reving it in park and this is when it was discovered. I tried again in Neutral and it still continued. I will try later today while the car is moving and I will put the peddle to the floor and see what happens.

THANKS for the help

yeah just don't floor from 0, try it when you are doing 30 then floor, don't strain the drivetrain.

as for my limiter, it won't go over 4100 at park or N. As I said redline is at 5700 on my 04, 3.7

 

[JeepJeepster]

Ive never gotten mine up to 4k when in park. I wouldnt know if mine does it or not, but guys use to to it all the time at highschool. They would all sit around and bounce them off the rev limiter. \/ :-s

 

[tjkobs7926]

Yeah...I got on the hwy and was almost able to red line before I got going 30 miles over the limit. Thanks for the help...I got a little nervous before....but I am alright now...thanks again

 

[fasto82]

i always enjoy making my libby shake every now and then. just throw it in park and hit the gas a couple of times until u get it up to 4k rpm. i guess theres a rev limiter when its in park or neutral so u dont kill it.

 

[hyde]

i always enjoy making my libby shake every now and then. just throw it in park and hit the gas a couple of times until u get it up to 4k rpm. i guess theres a rev limiter when its in park or neutral so u dont kill it.

I do that in N when I want the dude in front of me to go already.. what I do when I see that he is idling up ahead just as I get closer at slow speed, i drop it into Neutral and vvrrmmm. I don't care if it makes no difference to him, but it sure looks great and sounds mad. A few times dude in front stuck his hand and did sorry wave. It's better than honking!

 

[indieaz]

Yes, this is normal. It's a safety precaution to keep people who don't know what they're doing from destroying an engine by causing their valves to float revving to 8k RPMs in neutral. Looks like it's working! #-o