RPM jump
 

Hey guys,

I'm new here, so sorry if this is a n00b sort of question. I didn't see this exactly in any other threads.

Anyway, I have a 2k3 evo VIII. I take really good care of it (change oil on time, etc.), dont' race it much (ok a bit on the streets, but never on a race track. Yeah, I know, shame on me). In other words, I don't pound on it, even though it's made to take a beating.

I recently noticed that sometimes at around 3k - 4k RPM's, it'll jump about 500 RPM's and back down and then start accelerating normally. The clutch feels fine, the gears hold well. It's really weird. Car is bone stock. This is usually in 3rd gear, like when I'm just cruising along and hit the gas a bit to pass somebody up and it just does this weird jump. The dealer told me that it's the glaze on the flywheel, probably not the clutch and probably not the turbo, but to bring it in on Monday when their :mitsu: expert is in. Anyone ever have this happen? Any advice? I just don't want to get d1cked by the dealer trying to avoid blame.

The only issue that I've ever had with it was that the check engine light kept coming on signaling a engine misfire. They eventually replaced the fuel injectors and cat, but tried saying that I was putting crappy gas in there (no red tint from octane boosters like they were looking for).

i had this same issue about 1 week before my clutch started slipping... i would say its the first signs of your clutch going out...

I still have this problem happening. The clutch doesn't slip at all when I shift gears, though. This jump happens when it's fully engaged.

Test it by putting the car in 5th gear at low speed, then flooring it until the boost builds. This will make the clutch slip noticeably if it's going bad. The rpms will climb quickly, but you won't be accelerating...

Tried this. It doesn't jump then. At least, not until it gets to about 3k RPM's which is where it was jumping the whole time. The jump is not there if I gun it in first (starting from low RPM's, not launching it). It accelerates from 2k onward without problems. It only jumps if I'm cruising around 3k and hit the gas a bit. If I don't give it much gas and just let the RPM's gradually climb, it doesn't jump either.

This has been happening for a while (though I've been grandma'ing it so the jump doesn't happen). Just got new tires. I'm at a loss. Do you guys still think it's the clutch, or maybe the turbo/intercooler?

It's definately the clutch... these evo's have real problems with the stocker... I've had this happen twice ( the second time was from the clutch shop bending the disc when it was installed) it's a clip that saves your trannie when the clutch runs low.. so you notice this before the clutch completely goes and starts hurtin stuff... mitsu made this so the clutch goes before transfere cases and such.... make sure you don't go with a cerametallic clutch when you get a new one if you want streetability.... I've tried it and it don't work..... read up on clutches in the forum before getting a new one......................

BTW.... if you have an ODBII scanner you can plug it in for real time load ratings while accelerating and you'll see why this only happens in the higher gears.... in 1,2 and usually 3 there isn't much load on the car cause the gearing is so low.... even though it accelerates quickly it's not working the engine as hard by far so the clutch doesn't slip..


Remember it's only under high load that it will slip and it catches and drops back down because the organic disk of the clutch expands when it gets really hot and starts to grip enough to start pulling again.... don't go testing the jump in rpm or it will wear out extremely quickly..... I know because I let my dad test it for me and I couldn't even drive it afterward (had to limp my car to the clutch shop)

also... it doesn't jump till 3k cause that's when the powerband starts to hit and the engine starts really pulling...... I got my car used and always thought the powerband was weak to start till I realized the clutch was slipping when it first started to hit the band

i am having the same exact symptoms...damn it lol... time for another clutch...maybe the one i'm selling hehehe