Hi,
I just purchased a 2001 Durango 5.9 R/T. At idle, when I take the rpms up it starts to miss out at appox. 4200 rpms. Any help would be appriciated.

Thanks,
CALIBER 308

 

why are you taking it up that high without a load on it? you shouldnt be reving it that high in park or nuetral to begin with, its not good for the engine

the other thing is that you are approaching the rev limiter which will cut spark or fuel when you reach it.

the first thing you can do about misfire problems is to replace the plugs, wire, cap and rotor, use only champion copper core spark plugs, gapped at .040 and quality wires, and a cap/rotor combo with brass contacts.

(btw 5.9L rev limiter is 4700 in park, and nuetral, and 5400 in drive)

 

Uhhh. Let me be the first to ask the obvious. Why are you running the RPMs up to 4200+ at idle?

 

LOL SS, you beat me to the post!!

 

yes i did

 

Well, This is my first Durango. My 1987 Mitsu. Starion ESI-R Revs to 7000 with a 6500 rpm rev. limiter installed by me. I didn't know that Durangos had one??? It is nice to know.

CALIBER 308

 

First Durango or not, as shrpshtr325 posted above, there is no reason to rev at idle. None really. You are just ruining the motor, regardless of what motor.

Specs and tolerance isn't the same on road vehicles as they are on race cars. Revving the motor is useless on a road vehicle. The power has no where to go since it isn't being transferred to the drivetrain. Thus, the internal parts are absorbing the power and causing damage over time. More than one teenager has blown a motor from repetitive damage from useless revs.

With that said, perhaps you had a valid reason we can think of. If so, it is still never a good idea and there are better ways to check on valid reasons. Let us know what you were looking for and perhaps we already have the answer. Like... "is there a rev limiter on my D?" "Is there a max RPMs?" etc.

Sorry.

 

This is not my first rodeo. I am 55 years old and have been rebuilding cars and engines since I was 16 years old. True, this is my first Durango, but not my first experience with revving cars to over 5000 rpms at idle. To me, with my experience in engines, revving a 360 ci.to 4200 rpms at idle or otherwise should not be a problem, now I know it has a rev. limiter so it won't go above that. I'm not out to blow up my engine, but for a rev. limiter to be set at 4200 at idle is to me a little low. Hell, Stock BB and SB Chevys will do 6000 rpms easy, at idle or WOT. How do I know? I've built them from bare blocks.

Thanks for the info,
CALIBER 308

 

FWIW, rev limiter is not set to 4200. The rev limiter kicks in at 4000 when in PARK, 4800 when in low gears and the fuel cutoff point of the stock PCM is 5500rpm at WOT, at that point the PCM will cut off the fuel and force the engine to cease revving up. Any stumble at 4200 is normal and is the PCM programmed and designed to try to prevent pending damage.

IndyD

 

Stock BB and SB Chevys with electronics will not rev past 5000 rpms. Carbureted and fuel injected cars are totally different. Most fuel injected cars with electronics whether it be an ECM or PCM are ALL limited to certain high rpm's unless it is over ridden with some type of tuner. Foreign cars are also the same, limited in park or neutral to a certain no load rpm. Just like Indy said before, why even do it? And I am 51 years old and know it is not a good thing to do and I have also built many hot rodded engines in the past.