Clutch slip under load?

[steefnap]

Hey everyone,

Need some feedback on something. I was on the highway and downshifted to pass a slow moving vehicle. I had the pedal down about 3/4 and noticed a sudden loss of power, making the car shudder. Then it regains the power and continues to climb, and shudders again. It seems like a brief clutch slip. Could it be that, or perhaps a problem with fuel? I am running 91 octane and no engine management. I do not drag it or autocross it, but I do have mods on my car and drive somewhat aggressively. I also have a slow commute to work, so I am always on and off the clutch. Is it just because I have a little more horsepower now that the clutch can't handle it?

What about warranty on the clutch? I'm at just over 1 year, and 24000KM's.

 

[V-tecThis]

I kinda feel like a have a small miss fire if i really put it down and accelerate fast but i hope that isnt a problem with my clutch although it could be. Ill ask my brother he works for Mazda service at the dealership down the road.

 

[jcgemt2003]

ok...first off if your using 91octane when you can get 93 your gonna shorten the life of your motor to say the least....second...there is a PCM reflash (tsb recall)....its for powerloss..use the search button for more info...your dealer will reflash your cars ecu if your car falls within the affected vin...YOU MUST USE 93 OCTANE.....!!!!!!your car has a turbo and is tuned for 93octane...if your using less when your in wide open throttle or full boost you are causing your motor to knock (detonate)....which will eventually BOOM!!!!

 

[steefnap]

I will try 93 Octane... I think I know a couple places that have it. But I am concerned as I have been WOT before with no sudden shudders, it's only recently that this has started to happen. And the power loss happens for a split second, it's not like she runs out of breath or anything and I can't accelerate. It's almost like I hit a pothole on the road or something, it's that sudden and then it recovers.

 

[pHeeL tHiZ ViBe]

ok...first off if your using 91octane when you can get 93 your gonna shorten the life of your motor to say the least....second...there is a PCM reflash (tsb recall)....its for powerloss..use the search button for more info...your dealer will reflash your cars ecu if your car falls within the affected vin...YOU MUST USE 93 OCTANE.....!!!!!!your car has a turbo and is tuned for 93octane...if your using less when your in wide open throttle or full boost you are causing your motor to knock (detonate)....which will eventually BOOM!!!!

his motor will not knock on 91..mazda has clearly stated that the speeds can safely be run on 89 octane in an emergency.

but anyway..
1. the stock clutch is weak, but i don't think what your describing is clutch slip. clutch slip would cause the motor to rev, and you would notice that not a shutter.

2. i think you are experiencing fuel cut my friend. it does kinds feel like a shutter sometimes, or even a bump in the road along with a power loss. and it only happens for a split second.

when my car hits fuel cut on the freeway, its usually when i downshift and go WOT. and the car pulls for a second, then cuts power in a very quick shutter like fashion (along with some backfiring he he, thanks to my super duper flow exhaust ), then i continue to pull through the gear.

 

[pHeeL tHiZ ViBe]

one way to tell if its your clutch is to do a small little test launch, mine slips if i launch past 4k almost every time. depending on how well i engage it.

try it on a hill, and if your clutch is bad i promise you'll know it. mine has been slipping for 15,000 miles now, and somehow it still hooks up great in every situation except when i launch over 4k haha

 

[jcgemt2003]

his motor will not knock on 91..mazda has clearly stated that the speeds can safely be run on 89 octane in an emergency.

but anyway..
1. the stock clutch is weak, but i don't think what your describing is clutch slip. clutch slip would cause the motor to rev, and you would notice that not a shutter.

2. i think you are experiencing fuel cut my friend. it does kinds feel like a shutter sometimes, or even a bump in the road along with a power loss. and it only happens for a split second.

when my car hits fuel cut on the freeway, its usually when i downshift and go WOT. and the car pulls for a second, then cuts power in a very quick shutter like fashion (along with some backfiring he he, thanks to my super duper flow exhaust ), then i continue to pull through the gear.

Like you said..safely run on in an emergency....as in....AN EMERGENCY...so you shouldnt be WOP throttle with 89 or 91 octane if you have access to 93octane.....dont tell this guy his car is fine on 89 octane please...but I do agree now that yes...it sounds like fuel cutt....but why would he fuel cutt?.....I mean other than for obvious reasons like heavy to moderate modification...maybe cool weather....he doesnt have alot of mods....I dont think the stock clutch is weak at all....Im having mine replaced as we speak and its only after about 50 5k launches that its just now starting to slip.

 

[pHeeL tHiZ ViBe]

very true lol, i was in no way saying it is okay to run 89 octane. i suggest 93, and recommend atleast 91...here in SLC we are stuck with 91

and ya, mines had a few launches on it haha. so maybe not that weak, but too weak hehe

 

[pHeeL tHiZ ViBe]

a quote from Mazda:

"fuel octane:

The MZR 2.3l L3T engine has a high compression ratio for a turbocharged vehicle of 9.5:1. Typically turbocharged engine compression ratios are in the range of 7.5:1 to 8.5:1. This engine also has high boost pressure from the turbocharger 15.6 psi. Typical turbochargers boost from 5 to 12 psi. When you combine a high compression ratio and high boost, the result is a higher compression engine, somewhere in the range of 11:1. Higher compression engines require higher octane fuel.

Using lower than 91 octane fuel is not recommended. Lower octane fuel must be injected and ignited earlier. Less timing advance results in lower power and more heat. This engine should be run with 91 to 93 octane, 93 is ideal for its compression ratio. There are several disadvantages to lower octane fuels, less power, more heat, lower fuel economy, more carbon deposits. 89 octane should only be used in an emergency if 91 octane is not available.

The engine management system is able to seamlessly modify the ignition timing and fuel delivery for the entire range of fuel octane from 89 to 93 without detonation. it is also designed to protect the engine from damage due to lower octane fuel. When low octane fuel is used, the fuel delivery and ignition timing are retarded and power output is reduced. Continued operation with low octane fuel can result in increased engine intake air temperatures, when temperatures exceed safe levels, the PCM commands the turbocharger waste gate regulator solenoid off at 4200 rpm. With the waste gate regulator solenoid off, the waste gate opens earlier to reduce heat. A customer using low octane fuel in hot climates may describe this as a loss of power over 4000 rpm."

pretty sure, your problem has nada to do with fuel quality.

 

[steefnap]

2. i think you are experiencing fuel cut my friend. it does kinds feel like a shutter sometimes, or even a bump in the road along with a power loss. and it only happens for a split second.

when my car hits fuel cut on the freeway, its usually when i downshift and go WOT. and the car pulls for a second, then cuts power in a very quick shutter like fashion (along with some backfiring he he, thanks to my super duper flow exhaust ), then i continue to pull through the gear.

YES, that is it exactly! I noticed it when I downshifted in order to swoop past somebody on the highway. It was a VERY brief shudder, and then it goes again. It's not drawn out at all. I have a very free-flowing system as you can see with the mods. Should I look at getting a Fuel Cut Defender add-on for this? Will this cause any sort of long-lasting/eventual damage to my engine?

 

[ccann26]

i have a speed3 and had the transmission replaced at 15500 miles guess i'm a little hard on it but I've had loss of power several times followed by foul brake type smell i would say yeah its the clutch . But its onley happened to me at the time of engagement and stops when I let off the load not when its already engaged . If you know what i mean.....

 

[jcgemt2003]

YES, that is it exactly! I noticed it when I downshifted in order to swoop past somebody on the highway. It was a VERY brief shudder, and then it goes again. It's not drawn out at all. I have a very free-flowing system as you can see with the mods. Should I look at getting a Fuel Cut Defender add-on for this? Will this cause any sort of long-lasting/eventual damage to my engine?

Try the fuel cut killer...shouldnt see any more problems...

 

[pHeeL tHiZ ViBe]

he is right, its definitely your best bet. unless you plan on getting a standback? then its a waste, cuz you'll have to take it off.

 

[steefnap]

Not planning on getting a standback at all. I think once I get the RPM Springs on there, I am probably done. At least until I pay off the car. Too many mods so far!! It's addictive...