only in a certain RPM/boost point? I doubt it.

 

I noticed when the clutch is cold has alot more grip compare to when its fully warmed up

 

hmm.. sorry I have yet to encounter this problem so Im only trying to piece all the info together from all the posts. now I think about it if you shifted into neutral and the rpm still rises... then the problem lays within the engine department

 

Yes, but mine does it no matter if ive been driving short period or long period, enough to let the engine warm up along with the tranny, just seems to happen more when its cold out, not depending on how warm the tranny or engine are.

 

I work next to a mitsubishi dealer, ill go ask the techs there if they have seen this problem before and what did they do to fix this. hopefully ill have an answer for you this afternoon

 

That would be excellent.

 

good luck and my guess is that they will tell you it's normal

I have to second that the problem could be th stock clutch or throwout bearing.

 

Well, I'm thinking and still don't buy this, what makes the transmission spin? The engine in the case of that you are acceleration or keeping just enough throttle to keep a steady speed, otherwise the weight and speed of the car in case you are decelerating with the clutch still engaged.

So if you are running at a certain speed the clutch is engaged and running at say 6k rpm, when you then let go of the accelerator and press the down the clutch what could then possibly make the transmission or the clutch spin any faster on flat ground?? NOTHING!!! The only thing that could increase the rpm would be a down shift which would make the transmission spin faster and then if you engage the clutch again this would make the engine rev higher as well but that has never been the case here so it has nothing to do with the problems we are seeing here, period.

If your theory about the clutch were correct you should be able to let go of the accelerator at 7k, let the car slow down to say, 6k, then disengage the clutch and get a sudden increase of rpm. I can tell you for sure that would NEVER happen. As a matter of fact I have tried just that in my car and if I let go of the accelerator and waiting a bit longer that “normally” before disengaging the clutch and make my up shift this problem never occurs. Doesn’t matter at which rpm or in which gear, it never happens.

I’m convinced this has something to do with the throttle not closing properly. Then what could cause that I have no solid proof of at this moment. It could be carbon build up in the throttle housing, throttle cable not lubricated enough, the spring that closes the throttle lost its tension slightly, too high boost so you need a stronger spring, really don’t know but it’s not the clutch, fore sure. On thing is pretty obvious though, lots of people seam to have this or similar problems as have been discussed in this thread before so we just need to find the problem and hopefully it’s easy to fix.

If somebody still would like to suggest it’s the clutch please provide a feasible and technical explanation on why you think so so I can understand what you mean.

Thanks,

 

I agree

 

^^^I agree...I also tried tightening my throttle cable which was loose, tightened it up to where it should have been but that did not help either. Im also very very anxious for someone to find a cure.

 

You're absolutely right EVOII SWE the RPM should not rise even with the clutch engaged, it would only slow down the RPM from dropping. Now Im more curious about whats causing this problem since Im hoping to get my Evo in the next few month. I spoke with the some techs from the local dealer and they said they have not seen any thing like this before..sorry I tried

 

Based on my research it may be throw out bearing not releasing so as a result the engine spins and adds RPM's. Based on infromation I have looked at the cars that have the RPM rise problem have a clutch that grabs and mine was the same. The throw out bearing however may not be doing it's job. It is bearing which is moving part that can wearout before the clutch does.

I changed my clutch not because it wasn't grabbing but engament felt weird which is what would occur with a bad throw out bearing.

Here is some stuff I found on the web.


http://www.carcarecouncil.org/Manual..._bearing.shtml

Description: The throw-out bearing, or clutch release bearing as it's sometimes called, is located between the clutch fork and the pressure plate fingers. The throw-out bearing only operates when the clutch pedal is depressed; the bearing is not designed for continuous use.


Purpose: When the driver steps on the clutch pedal, the throw-out bearing applies force to the fingers of the spinning pressure plate to release the clutch. When the clutch pedal is released, the bearing sits idle and does not contact the pressure plate fingers.

Maintenance Tips/Suggestions: The classic symptom of a worn throw-out bearing is a whirring or growling sound when applying the clutch pedal, which goes away when releasing the pedal. Premature wear of the throw-out bearing can occur when there is insufficient clutch play, resulting in a throw-out bearing that spins continuously. If the bearing fails, it may seize and quickly wear the fingers of the pressure plate. The throw-out bearing does not require routine maintenance, but should be replaced when clutch replacement becomes necessary. Consult a professional technician to determine whether the throw-out bearing or other parts of the clutch assembly need replacement.

 

http://www.carecstasy.com/Technical/..._Operation.htm

The "throw-out bearing" is the heart of clutch operation. When the clutch pedal is depressed, the throw-out bearing moves toward the flywheel, pushing in the pressure plate's release fingers and moving the pressure plate fingers or levers against pressure plate spring force. This action moves the pressure plate away from the clutch disc, thus interrupting power flow.

Mounted on an iron casting called a hub, the throw-out bearing slides on a hollow shaft at the front of the transmission housing. The clutch fork and connecting linkage convert the movement of the clutch pedal to the back and forth movement of the clutch throw-out bearing. To disengage the clutch, the release bearing is moved toward the flywheel by the clutch fork. As the bearing contacts the pressure plate's release fingers, it begins to rotate with the pressure plate assembly. The release bearing continues to move forward and pressure on the release levers or fingers causes the force of the pressure plate's spring to move away from the clutch disc. To engage the clutch, the clutch pedal is released and the release bearing moves away from the pressure plate. This action allows the pressure plate's springs to force against the clutch disc, engaging the clutch to the flywheel. Once the clutch is fully engaged, the release bearing is normally stationary and does not rotate with the pressure plate.

 

I know perfectly well how a throw out bearing works but I’m starting to doubt that you understand the fundamental design and operation of a manual gearbox transmission? Not trying to be rude here in anyway but think about this:

If things would be the way you say the transmission some how needs to spin faster and then in turn make the engine spin faster as well. Until you disengage the clutch the engine and the axle into the transmission has the same rpm so why would disengage the clutch suddenly cause the transmission to increase its speed? What force do you mean could cause the increase in transmission speed? That would also mean that the speed of the car suddenly must increase as that is directly connected to the gearbox. Nothing “drives” the transmission except for the engine or the speed/weight of the car when decelerating with the clutch still engaged. It’s not like the transmission is its own little turbine or something that could produce torque to spin the engine or the car.

All this is as long as you don’t downshift because this would of course cause an increase in rpm when you engage the clutch again but the problems we, or at least I, experience is just in that split second when you come of the accelerator and disengage the clutch.

Could somebody else please try to explain this in a better way if I still doesn’t seam to be able to?

 

yup exactly what I am experiencing as well.