Grinding noise in neutral

[humfrz]

Originally Posted by FR-Sky

I mean as long is normal,,then i am fine with it.
I just did a little bit research right now,,many people say its a high pressure fuel injection, and its normal. so i dont know...

If you haven't already done so, you will find that the FR-S can make lots of "unfamiliar" sounds.

Yes, one of them is a TOB going bad. It goes from silent to whirring to grinding to screeching to howling (as it stops and is pushed into the rotating clutch pressure plate fingers).

Another common sound is the HPFP (High Pressure Fuel Pump). It can be silent .... it can tick ... it can chirp (like crickets) ..... it can go rat-a-tat-tat ...and many other sounds ...... depending on type of fuel, temperature, engine speed (fuel demand), and phase of the moon (seeing if you're payen attention).

Like my oncologist tells me ....... "no change is good"; so, if sounds don't get any louder/worse, your car is most likely OK.


humfrz

[FR-Sky]

Originally Posted by humfrz

If you haven't already done so, you will find that the FR-S can make lots of "unfamiliar" sounds.

Yes, one of them is a TOB going bad. It goes from silent to whirring to grinding to screeching to howling (as it stops and is pushed into the rotating clutch pressure plate fingers).

Another common sound is the HPFP (High Pressure Fuel Pump). It can be silent .... it can tick ... it can chirp (like crickets) ..... it can go rat-a-tat-tat ...and many other sounds ...... depending on type of fuel, temperature, engine speed (fuel demand), and phase of the moon (seeing if you're payen attention).

Like my oncologist tells me ....... "no change is good"; so, if sounds don't get any louder/worse, your car is most likely OK.


humfrz

yea its has the chirp sound when idling, other than that everything else is fine. well,,700 miles until 22500 service. Just have to live with it for now.

Thanks guys

[humfrz]

Originally Posted by FR-Sky

yea its has the chirp sound when idling, other than that everything else is fine. well,,700 miles until 22500 service. Just have to live with it for now.

Thanks guys

If the sound is the HPFP, it doesn't mean it's going bad. Some of them just make that sound.

Here's what I tell some folks:

Yep, that sound you hear is the ultra-high pressure fuel pump. In fact, the engine requires two fuel injection systems to keep up. You see, the engine sits in there, flat, like a Porsche engine and has a really high compression ratio; even calls for gas with a higher octane rating that is found at most pumps.

Why? Because racecar. ..........


humfrz

[FR-Sky]

Originally Posted by humfrz

If the sound is the HPFP, it doesn't mean it's going bad. Some of them just make that sound.

Here's what I tell some folks:

Yep, that sound you hear is the ultra-high pressure fuel pump. In fact, the engine requires two fuel injection systems to keep up. You see, the engine sits in there, flat, like a Porsche engine and has a really high compression ratio; even calls for gas with a higher octane rating that is found at most pumps.

Why? Because racecar. ..........


humfrz

phew,,thought it would be something serious.
Lol u sounds like the guy with the simpson icon!!!

[humfrz]

Originally Posted by FR-Sky

...............Lol u sounds like the guy with the simpson icon!!!

Ohhhhhh...........I hope he don't see that comment ....... he will be really pissed ......


humfrz

[FR-Sky]

Originally Posted by humfrz

Ohhhhhh...........I hope he don't see that comment ....... he will be really pissed ......


humfrz

oh Jesus. i am glad he is sleeping right now, and i hope this this post will sink.

[pantdino]

Originally Posted by stevesnj

That's the throw out bearing, it's normal. If you get a screeching sound get it replaced. Until then turn up the tunes.

I don't think so. The TOB should only be spinning under load when the clutch is pushed IN. With the clutch out it's just sitting there between parts and should not be spinning, therefore not making noise.


Trannies have an input shaft that spins whenever the clutch is out (engaged). If the bearings on that shaft go bad it makes noise.


Have a tech listen to your car-- some slight noise is normal just from the gears in the tranny spinning when the clutch is out, but it should not be a grinding noise.

[humfrz]

Originally Posted by pantdino

I don't think so. The TOB should only be spinning under load when the clutch is pushed IN. With the clutch out it's just sitting there between parts and should not be spinning, therefore not making noise.

Well now, @pantdino , back in the 80's or earlier, you would have been correct most of the time.

I had the same misconception until ol @Ultramaroon enlightened me.

The TOB in our cars is an "active" type, meaning it's spinning any time the engine is running. True, it's under pressure only when the clutch is pushed it.


humfrz

[pantdino]

Originally Posted by humfrz

Well now, @pantdino , back in the 80's or earlier, you would have been correct most of the time.

I had the same misconception until ol @Ultramaroon enlightened me.

The TOB in our cars is an "active" type, meaning it's spinning any time the engine is running. True, it's under pressure only when the clutch is pushed it.


humfrz

What is the advantage of that? Instead of spinning like 1/10,000 of the time it's spinning 100%. I guess they figure if its not under load it won't make any difference? But spinning still creates heat and uses up the grease in the bearing.

[humfrz]

Originally Posted by pantdino

What is the advantage of that? Instead of spinning like 1/10,000 of the time it's spinning 100%. I guess they figure if its not under load it won't make any difference? But spinning still creates heat and uses up the grease in the bearing.

Well, now, @pantdino , that's an interesting question and one that I had.

Some ol boy somewhere on the interweb explained it this way:


"On "older" cars (prior to about 1980) the clutch system used "free play", i.e. there was a small gap between the throw out bearing and the pressure plate fingers, when the pedal was up (clutch engaged). Throw out bearings were not designed to run a lot, and these bearings could not compensate for mis- alignment.

Starting in the early '80's most clutch systems switched to "self centering" throw out bearings. At the same time, the clutch systems changed from "free play" systems to "constant running" (in other words, the throw out bearing was in constant contact with the pressure plate fingers, and always turning) systems. And they also incorporated self adjusting systems in the release linkage or pressure plate itself."


Now my (humfrz) take on the situation is that, most, back in the day clutches, were dis-engaged with mechanical linkage. So, the TOB was set close to, but not touching, the fingers of the pressure plate. So, when the clutch pedal was pushed down, the fork pushed the cold, non spinning, TOB, against a bunch of steel fingers that were rotating at the speed of the engine.

Talk about a "cold start" and a sudden temperature change......

Now with the hydrolytic clutches, the inner workings of the slave cylinder puts a 5-15 lb/sq/in pressure on the TOB which keeps it in constant contact with the rotating pressure plate fingers. So, it stays warm by spinning all the time the engine is running. When the clutch pedal is depressed it is called upon to "work" by pushing the pressure plate fingers, thus releasing the pressure on the clutch disk.

So, which would the bearing rather do ...... spin all the time and work when called upon ........ or sit there cold and get slammed up against steel fingers spinning at several thousand RPMs .... every now and then....... ??

If I don't have this completely straight, I'm sure ol @Ultramaroon and maybe others, will chime to correct me ......


humfrz

[Ultramaroon]

Yessir. That's better than I would have done. Part of that magic is, as you mentioned, the self-centering feature of the TOB. Without that, the whole thing would end up a pile of dust in short order.

[zc06_kisstherain]

I just noticed this light spinning noise when all my raido and AC is off. when idling at stop, i hear this and noise goes away when clutch is in.

[Icecreamtruk]

Originally Posted by zc06_kisstherain

I just noticed this light spinning noise when all my raido and AC is off. when idling at stop, i hear this and noise goes away when clutch is in.

Input shaft spinning in the transmission. Normal.

[zc06_kisstherain]

everyone talks only "it's your TOB" shit so i was like wtf. lol