Another Noise….

[Homeboy981]

I am getting a "loose nut" sound when I coast. No…not me!

When in gear I cannot hear anything but exhaust sound. When the vehicle is out of gear (in neutral and coasting) it sounds like the transmission has a noise once in a while that sounds like a 'marble in a can' only for an 1 second or so. I observed the noise becoming more frequent and parked the car.

To shed more light on cause I have recently been down a dirt road…that was being re-surfaced, so it was DOUBLE dirt and gravel - my car was a mess AND I recently put on a clutch/LWFW combination.

Someone suggested they have had the LWFW pressure plate loosen on them. What would that sound like when the bolts let go?

I have not driven car for a couple days since it made that unnerving noise. I was planning on going back to pull the transmission and clutch….unless someone has a better idea, he said hopefully.

Are there specific places that may catch rocks around the tranny or something else that I can check?

[Flavor 987S]

Well, a LWFW will be more noisey vs the stock set-up. So, it could be normal. But I would not describe the normal louder LWFW sound "as a marble in a can". Can you post an audio clip?

[woodsman]

I found 2 loose bolts on my pressure plate but also another for the flywh pos sensor was loose and they never made any noise but the fingers were then working unevenly and this caused the release bearing to break off it's mounting clips and then strange clutch behavior began over 4000 RPM.
With the single-mass flywh there is gear rattling from the gearbox and can be heard from within the car only in a quiet environment while idling, or while standing at the back of the car. I'm not sure if that's what your hearing but it may be premature to tear out the tranny just yet. There's others who can add more than I can but let the scientific inquiry take its course Homeboy!

[Homeboy981]

First off, thanks for the replies.

The 'strange' noise is OVER and ABOVE the normal "dieseling sounds" the LWFW makes at idle. I first noticed it between shifts, then I tried coasting without being in gear, and now I have more evidence.

I was hoping for a rock but I started the car yesterday and heard the noise at idle. I would record it but the noise is un-nerving!

Looks like I'm going in.

Prepare the patient for surgery!

[JAAY]

How old is your flywheel that is in there now? The Dual mass when it goes is noisy as hell . mine is shot right now and shakes like a mofo. I am actually not driving mine right now till I do a clutch job.

[JAAY]

Nevermind.. Just saw you have an aasco.

[woodsman]

hey homeboy before you tear it apart--which side is it... exhaust or trans or...-I'm hoping it's a nut in a cat for yea!--0nce the mufflers off, is it still there? etc.

[Homeboy981]

Thought I had a simple exhaust leak, as suggested by Woodsman. - since I just recently installed headers! The sound is definitely coming from the transmission! Noticed it first when coasting - now it is FULL-TIME!

Here is a 7 second clip of the noise at startup, as suggested by Flavor 987S.

* Listen at the 2-3 seconds mark for the scary RATTLING NOISE. I did not leave the starter engaged long enough to start to minimize damage.

Within 1,000 miles I have added a Sachs Clutch, Aasco Lightweight Flywheel, Throwout Bearing, Pressure Plate & IMS.

This is where I need to rely on this Forums' vast knowledge (I have tried the search function and gleaned some info). So here is the dilemma….

Everything was torqued to spec and thread locker used….except the pressure plate bolts. The pressure plate bolts were torqued to Aasco's recommended spec of 20 ft.lbs. (instead of 17 that Bentley recommends) BUT Aasco DOES recommend using Loctite on these particular bolts, Porsche does NOT. Which is correct? I decided to NOT put Loctite on since it was a factory part and did not take into account the Aasco (not being a dual mass FW) shakes the tranny a fair bit, otherwise known as sounding like a "diesel".

Any suggestions, short of telling me where to dump it, are appreciated. Thanks for the responses thus far. I want to keep the LWFW - already addicted to the performance!

Strange Porsche Sound 5-16-13 - YouTube

NOTE: This is the only downside, emissions aside, to running headers…you cannot hear ALL the OTHER sounds the car is making! But it sure DOES RUN WELL…when it's running!

[shadrach74]

Me thinks it likely that something was not torqued properly when you last had the tranny out. ME also thinks it's flywheel/engine side related if you're getting it in neutral. Throw out bearings can make noises in neutral, but I've never heard one that sounded like that...

Good luck!

[cameronzero]

i know in the miata's that the sound you're describing comes from worn bearings in the water pump and alternator, especially when the belt is either too loose or too tight. they can also come from the crank if the rotating assembly isn't balanced (using the stock crank pulley on the 1.6) and you stay high in the RPM range. factory redline is 7.2 (1.6) and after the LWFW a good amount of people will go 8k+ with cams and dual spring valves.

did you balance your whole rotating assembly before instilling the LWFW on the boxster? i read that installing a LWFW in place of a dual mass without a balance can lead to catastrophic engine failure due to the vibration negating effect of the dual mass fly wheel. also, since both the pressure plate and LWFW are not factory, it's safe to assume that the factory manual will not cover them. go by what the manufacturer recommends when installing their parts, as i would hope (hope being the main point here) that they did actual product testing on the applied parts with the vehicles they are selling them for. as some parts can be pretty universal, it could be possible that the manufacturers recommendations will not suit your set up.

[woodsman]

hey Homeboy, I wonder if the tranny's already been apart on that car and was never repaired properly? How many miles did you drive it before taking everything apart ? I find it hard to believe a bolt YOU tightened could already come loose. I listened to your video and really couldn't decipher any of the sounds. At least it'll come apart easy. I'm sure Aasco calls for loc-tite only on the flywheel bolts and there's a mismatch of metals to consider when bolting the p p down ( long - term oxidation) and this isn't the case with a dualmass but I decided to loc tite the pp too- major bummer for you whatever the prob is!

[Homeboy981]

Originally Posted by woodsman

hey Homeboy, I wonder if the tranny's already been apart on that car and was never repaired properly? How many miles did you drive it before taking everything apart ? I find it hard to believe a bolt YOU tightened could already come loose.

Yep. I tightened it. How did you know I have a tendency to 'over-torque'? That's what I get for relying on a torque wrench…beats a stripped bolt I guess!

I made it almost 1,000 blissful miles. Just enough to be left wanting. The speed and sound of all the cumulative mods is certainly intoxicating.

Here's hoping it is minor.

But, for now, she will remain parked - while I make a living! Those houses don't buy themselves!

[woodsman]

houses be dammed, get 'er ass up and get in there man!

[Homeboy981]

Just to update…got the engine torn down to the point of RMS replacement. Thought I would find an improperly-torqued bolt.

Took it all apart. The transmission is out and dry with some dust, not bad. ALL the bolts were tight to spec. No exhaust shield rattles. No muffler noises. 02 sensors & header bolts are tight. LWFW was stuck on there like glue too. No slippage in the pressure plate bolts either. Water pump has 8k miles on it.

Was it all for naught?

Things to still check:
* Spark Plugs
* Header Bolt Torques
* RSS Pulley - though I doubt it
* Oil Filter for metal pieces

The starter motor (see pic). The shaft had a little 'play' or 'wiggle room' in it, is that normal?


I implore you...Can ANYONE possibly suggest something else to check & help a Boxster guy out?

Thank you in advance.

Signed,
Stuck In The Slow Lane

[EssexPorsche]

Hey Homeboy,
You are just not getting the breaks.
That sound clip was very short (I understand why), but by the time it had fired, and disengaged the starter it was very hard to pin-point the sound.

Was the noise rythmical- in time with the engine revs? Or was it random, like a pinball banging in different directions?

If it had rythm could it be crank related (shells/bearings) or even a piston picking up on a bore.

I ask as I have read that replacing the dual mass flywheel with a LWFW can have detrimental effects on other components if the are not lightened and balanced also?
So whilst everything you have just taken apart and reinstalled in the last 1000 miles might be tight- the issue could now be something deeper inside with something indirectly affects by the mods?
Rather than just something loose from on the new components?

Keep us updated buddy.

[woodsman]

you said;' it was definitely in the tranny' when I implored you to listen closely before taking 'er apart. I wonder if you could run the engine without the tranny in? then you'd know which it is. I know from first-hand experience that sounds travel and bounce off things in cars. Does the tranny look like it's been apart and if so , did they forget something?

[Homeboy981]

Originally Posted by EssexPorsche

Hey Homeboy,
You are just not getting the breaks.
That sound clip was very short (I understand why), but by the time it had fired, and disengaged the starter it was very hard to pin-point the sound.

Was the noise rythmical- in time with the engine revs? Or was it random, like a pinball banging in different directions?

Thanks EssexPorsche,
I KNOW you were "Made to care by your Mum" but I appreciate the sentiment and the suggestions just the same. In fact, you should thank your Mum.

In answer to the one question about the noise being rythmical, it is not. It is like a pinball hitting different spots and being thrown around by centrifugal force. It certainly sounded like a loose nut rattling around. Guess that describes me now..although not funny IF you're the nut!

[Homeboy981]

Originally Posted by woodsman

you said;' it was definitely in the tranny' when I implored you to listen closely before taking 'er apart. I wonder if you could run the engine without the tranny in? then you'd know which it is. I know from first-hand experience that sounds travel and bounce off things in cars. Does the tranny look like it's been apart and if so , did they forget something?

Hi Woodsman,

Can I run the engine without the tranny on? I need to put the flywheel on for starter to engage…but that is a possibility to try the old Dual mass FW and see IF it still make noise.

The tranny does not look like it has been rebuilt. Of course, I have heard that the LWFW can cause some issues, maybe it rattled the transmission to pieces? It is curious I first heard the noise between shifts and then 'out of gear' and now ALL THE TIME!

[BruceH]

I feel for you Mark! Wish I had an idea. Good luck!

[Perfectlap]

Have you tried posting on RennTech?