Clutch sutter/skipping. Diagnosis?

[overst33r]

Hi,

(sorry for the novel but I'd like to be descriptive)

My miata recently developed something I can describe as a clutch stutter/skip. I had an eventful past month or so with the car, so it could be a number of things that caused it.

The clutch is relatively new, previous owner replaced it a few months before I bought it, so it has about 20k on it at the most. I also replaced the clutch fluid about 3 months ago.

About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like. I continued throughout the rest of the day without any problems or symptoms.

The other day my car overheated because a heater hose busted. I got that fixed in a couple of days and the first time I drove it after I fixed the heater hose, the car did not take of like it used to. Right before the clutch engages at the top of the pedal travel it stutters and skips and the car jerks. This lasts for about a second or so. It is less pronounced the higher the RPM is I take off at.

I am perplexed at the cause of the problem but have a hunch it will be expensive to fix it...

Could there be fluid on the clutch/flywheel? Is there air in the system?

Can anyone enlighten me?

EDIT: after doing some more research, it seems that it could be bad/old motor mounts...

 

[iamwiz82]

Heater hose, huh? Did coolant get in the bellhousing? I could be way off, but it's kind of odd to have those two things happen one after the other.

 

[dandragonrage]

The only symptom is that it sucks during acceleration? It doesn't do anything else like surge or anything?

 

[overst33r]

Originally posted by: iamwiz82
Heater hose, huh? Did coolant get in the bellhousing? I could be way off, but it's kind of odd to have those two things happen one after the other.

The heater hose is a weak part in this car as it is located right beneath the cam angle sensor which is known to leak oil unless the o ring is replaced in a timely fashion. So it probably softened up the hose quite a lot and caused it to break. Not to mention that I replaced the radiator a week before the hose went.

I guess it's just at that point where the car needs to have things changed.

 

[overst33r]

Originally posted by: dandragonrage
The only symptom is that it sucks during acceleration? It doesn't do anything else like surge or anything?

No surging.

Just a horribly unsmooth take off as a result of the juddering.

 

[dandragonrage]

Does the clutch engage with the pedal any higher up than before, or does it otherwise tend to slip where it didn't slip before this problem?

About motor mounts, just have the car in neutral, e-brake on, and open the hood, car running. Pull the throttle a fairly good amount. The engine should rock a bit but it shouldn't jump at you.

 

[iamwiz82]

Originally posted by: mariok2006

Originally posted by: iamwiz82
Heater hose, huh? Did coolant get in the bellhousing? I could be way off, but it's kind of odd to have those two things happen one after the other.

The heater hose is a weak part in this car as it is located right beneath the cam angle sensor which is known to leak oil unless the o ring is replaced in a timely fashion. So it probably softened up the hose quite a lot and caused it to break. Not to mention that I replaced the radiator a week before the hose went.

I guess it's just at that point where the car needs to have things changed.

I have a Miata.

I take it you only replaced one of the hoses, not the other?

 

[overst33r]

Originally posted by: iamwiz82

Originally posted by: mariok2006

Originally posted by: iamwiz82
Heater hose, huh? Did coolant get in the bellhousing? I could be way off, but it's kind of odd to have those two things happen one after the other.

The heater hose is a weak part in this car as it is located right beneath the cam angle sensor which is known to leak oil unless the o ring is replaced in a timely fashion. So it probably softened up the hose quite a lot and caused it to break. Not to mention that I replaced the radiator a week before the hose went.

I guess it's just at that point where the car needs to have things changed.

I have a Miata.

I take it you only replaced one of the hoses, not the other?

No I replaced both. I didn't want to make that mistake.

 

[dandragonrage]

mario, see this: http://www.automotiveblogger.n...you-bought-a-girl-car/

 

[overst33r]

Originally posted by: dandragonrage
mario, see this: http://www.automotiveblogger.n...you-bought-a-girl-car/

Thanks.

I got it in the girliest color I could find.

 

[dandragonrage]

http://images.google.com/imgre...ra%26rls%3Den%26sa%3DN

 

[Zenmervolt]

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

 

[overst33r]

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how else you can stay in the powerband of such a high strung car... That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

 

[spidey07]

Broken clutch finger?

And you don't want wheel spin when you take off, that's bad, that's slow.

 

[overst33r]

Originally posted by: spidey07
Broken clutch finger?

And you don't want wheel spin when you take off, that's bad, that's slow.

Yes I am aware of that, but it largely eliminates the largest of initial shocks. I modulated the throttle shortly after I got wheelspin. Afaik, that is the quickest/safest way to launch a low torque rear wheel drive car.

Wouldn't the clutch finger affect all the gears?

 

[Gamingphreek]

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

 

[spidey07]

Originally posted by: mariok2006

Originally posted by: spidey07
Broken clutch finger?

And you don't want wheel spin when you take off, that's bad, that's slow.

Yes I am aware of that, but it largely eliminates the largest of initial shocks. I modulated the throttle shortly after I got wheelspin. Afaik, that is the quickest/safest way to launch a low torque rear wheel drive car.

Wouldn't the clutch finger affect all the gears?

yes, but it would depend on if the input so if your revs match you'd probably not even notice it and you'd probably only feel it at the last bit of the pedal. I'm no mechanic though.

You'd feel it depending on "load" you're putting on the flywheel/clutch junction when slipping.

-edit-
come to think of it if you broke a finger you'd probably have a lot more noise as that finger gets ground up.

 

[overst33r]

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

 

[spidey07]

Originally posted by: mariok2006
I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

Not to get off your OP here, but controlling that wheelspin/staying in the powerband is what your clutch is for.

 

[Gamingphreek]

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

I don't mean to come off rude by any means with that post. Wheel spin can happen with a perfect shift or start just from torque - You don't need to drop the clutch EVER to make that happen.

Staying in the powerband (Assuming you mean at peak torque), well you just have to accept that if you are going to be launching like that (Keep in mind, tire spin is inefficient at launch as is launching) you are going to incur a lot of wear and tear on your clutch - Honestly there isn't a reason that you should do that in my mind.

-Kevin

 

[overst33r]

Originally posted by: spidey07

Originally posted by: mariok2006
I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

Not to get off your OP here, but controlling that wheelspin/staying in the powerband is what your clutch is for.

I agree with you, but that is next to impossible with 130hp...

I controlled the wheelspin after I got off the line by modulating the throttle...

 

[overst33r]

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

I don't mean to come off rude by any means with that post. Wheel spin can happen with a perfect shift or start just from torque - You don't need to drop the clutch EVER to make that happen.

Staying in the powerband (Assuming you mean at peak torque), well you just have to accept that if you are going to be launching like that (Keep in mind, tire spin is inefficient at launch as is launching) you are going to incur a lot of wear and tear on your clutch - Honestly there isn't a reason that you should do that in my mind.

-Kevin

I'm not arguing the effectiveness of the launch. I'm just saying in order to avoid damage to the differential, the car needs to have a lot of wheelspin initially. I understand the wear and tear on the clutch, but I've never launched the car aggressively at all... 4k max with clutch slip was the worst I've done.

I figure if it can't take one clutch dump, there's something wrong in the first place... I didn't think my theory would be realized.

Although I'm still not sure the clutch dump caused it. Like I said, the car drove fine with absolutely no symptoms until the day after I replaced the heater hose.

 

[Gamingphreek]

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

I don't mean to come off rude by any means with that post. Wheel spin can happen with a perfect shift or start just from torque - You don't need to drop the clutch EVER to make that happen.

Staying in the powerband (Assuming you mean at peak torque), well you just have to accept that if you are going to be launching like that (Keep in mind, tire spin is inefficient at launch as is launching) you are going to incur a lot of wear and tear on your clutch - Honestly there isn't a reason that you should do that in my mind.

-Kevin

I'm not arguing the effectiveness of the launch. I'm just saying in order to avoid damage to the differential, the car needs to have a lot of wheelspin initially. I understand the wear and tear on the clutch, but I've never launched the car aggressively at all... 4k max with clutch slip was the worst I've done.

I figure if it can't take one clutch dump, there's something wrong in the first place... I didn't think my theory would be realized.

Although I'm still not sure the clutch dump caused it. Like I said, the car drove fine with absolutely no symptoms until the day after I replaced the heater hose.

What damage are you talking about with the differential that prevents you from launching normally?

Clutch slip, in my mind (Could be wrong) can be harder in some cases than a clutch dump (Read: Synchronizers, Clutch finger, etc...).

But I don't mean to take this thread OT and apologize for doing so.

As for the problem you are having-- I would imagine that some coolant got in there (If a finger broke off you would probably hear it getting pulverized in there) . It shouldn't evaporate as it is coolant...

 

[overst33r]

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

I don't mean to come off rude by any means with that post. Wheel spin can happen with a perfect shift or start just from torque - You don't need to drop the clutch EVER to make that happen.

Staying in the powerband (Assuming you mean at peak torque), well you just have to accept that if you are going to be launching like that (Keep in mind, tire spin is inefficient at launch as is launching) you are going to incur a lot of wear and tear on your clutch - Honestly there isn't a reason that you should do that in my mind.

-Kevin

I'm not arguing the effectiveness of the launch. I'm just saying in order to avoid damage to the differential, the car needs to have a lot of wheelspin initially. I understand the wear and tear on the clutch, but I've never launched the car aggressively at all... 4k max with clutch slip was the worst I've done.

I figure if it can't take one clutch dump, there's something wrong in the first place... I didn't think my theory would be realized.

Although I'm still not sure the clutch dump caused it. Like I said, the car drove fine with absolutely no symptoms until the day after I replaced the heater hose.

What damage are you talking about with the differential that prevents you from launching normally?

Clutch slip, in my mind (Could be wrong) can be harder in some cases than a clutch dump (Read: Synchronizers, Clutch finger, etc...).

But I don't mean to take this thread OT and apologize for doing so.

As for the problem you are having-- I would imagine that some coolant got in there (If a finger broke off you would probably hear it getting pulverized in there) . It shouldn't evaporate as it is coolant...

The actual shock of the wheels not breaking traction when launching could be catastrophic to the differential, so I've read. I dare not experience it.

I don't suppose there's anyway to check if coolant got in there short of separating the tranny from the engine.

 

[EightySix Four]

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Gamingphreek

Originally posted by: mariok2006

Originally posted by: Zenmervolt

Originally posted by: mariok2006
About 2 weeks ago, I was at an AutoX and I dropped the clutch at 6.5k RPM just to see what a proper start would feel like.

A 6,500 RPM clutch dump is not a "proper start". Whoever told you that is seriously misinformed.

That said, it does sound as though coolant got into the bellhousing and contaminated the clutch, which could cause some jitter/chatter upon engagement.

ZV

From what I've read, the majority of autocrossers prefer a high rpm launch in order to avoid bogging and damaging the diff. Wheelspin is preferred, similar to the S2000. I don't see how it isn't proper. That said, I've gotten plenty of wheel spin launching at 3-4k...

Wouldn't water leak into the bell housing as well? I've washed the engine more than once and never had any issues...

If coolant did get into the bellhousing, wouldn't it eventually evaporate or something to that effect?

You seem to know a decent amount about cars. What IN THE WORLD, then, would lead you to believe that it is ever PROPER to DROP your clutch?!?

Given that, this is coolant, evaporation generally doesn't happen at a high rate

-Kevin

I wanted some wheelspin and to stay in the powerband. I am not aware of any other way of doing such a thing besides dropping the clutch.

Yeah I figured I'd get nailed on that there... What about at least losing its slickness?

I don't mean to come off rude by any means with that post. Wheel spin can happen with a perfect shift or start just from torque - You don't need to drop the clutch EVER to make that happen.

Staying in the powerband (Assuming you mean at peak torque), well you just have to accept that if you are going to be launching like that (Keep in mind, tire spin is inefficient at launch as is launching) you are going to incur a lot of wear and tear on your clutch - Honestly there isn't a reason that you should do that in my mind.

-Kevin

I'm not arguing the effectiveness of the launch. I'm just saying in order to avoid damage to the differential, the car needs to have a lot of wheelspin initially. I understand the wear and tear on the clutch, but I've never launched the car aggressively at all... 4k max with clutch slip was the worst I've done.

I figure if it can't take one clutch dump, there's something wrong in the first place... I didn't think my theory would be realized.

Although I'm still not sure the clutch dump caused it. Like I said, the car drove fine with absolutely no symptoms until the day after I replaced the heater hose.

What damage are you talking about with the differential that prevents you from launching normally?

Clutch slip, in my mind (Could be wrong) can be harder in some cases than a clutch dump (Read: Synchronizers, Clutch finger, etc...).

But I don't mean to take this thread OT and apologize for doing so.

As for the problem you are having-- I would imagine that some coolant got in there (If a finger broke off you would probably hear it getting pulverized in there) . It shouldn't evaporate as it is coolant...

The actual shock of the wheels not breaking traction when launching could be catastrophic to the differential, so I've read. I dare not experience it.

I don't suppose there's anyway to check if coolant got in there short of separating the tranny from the engine.

The car doesn't have enough horsepower or grip to do that much damage to the diff. I'd just slip and modulate until it launches the way you want. No reason to drop it.