Whats the noise?

nick4tl

Member
Hi Everyone,
So Im at a loss really as to what is causing a noise in my 1.4 TDI AMF. Im attaching a link to a recording and would really welcome suggestions. Which I'll then feedback to the mechanic who is also a bit mystified at this stage.
Basically there are two symptoms.
1) A rattle when idling that disappears when the clutch is pressed.
2) A rattle when accelerating in 5th and 6th.

This rattle started soon after I had an MYP gearbox and new clutch fitted. We assumed it was a bearing in the gearbox. I then purchased a PTU gearbox (from a 2014 Audi A3 1.6 tdi 6-speed manual with 47078 miles).
When fitting the audi A3 gearbox we found the clutch slave cylinder had also failed so we replaced that and the clutch as it had fluid on it.
Annoyingly the sounds are exactly the same. A rattle when idling and a rattle when accelerating but only in 5th and 6th.

Im hoping someone may be able to suggest something. Id particularly welcome any feedback from anyone who fitted an MYP or other 6 speed box to an AMF, even if just to say it's working fine for them.

The sound was recorded in the cabin. It's not easy to hear when outside due to the noise of the engine.

P.S. (there's a microswitch or something gone in the door so thats the clicking on restart at 33sec. Ignore that)
Audio begins with clutch pressed.
Clutch released at about 2sec and pressed again at 7sec, released at 10.
listen to the sound here

Any ideas greatly welcomed.
N
 

dj_efk

A2OC Donor
Interesting. I am tempted to say you have two duff gearboxes with the same issue as I have no idea what else it could be, but that would be extraordinary.

Are you sure nothing is rubbing on the body anywhere? Maybe crawling around under the car with a stethoscope while it’s idling might be useful?
 

A2Z

Member
Something that's been on my mind this week is the alternator pulley....... worth checking as mine sounded similar before it flew off?
 
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kp 115

A2OC Donor
Hi Everyone,
So Im at a loss really as to what is causing a noise in my 1.4 TDI AMF. Im attaching a link to a recording and would really welcome suggestions. Which I'll then feedback to the mechanic who is also a bit mystified at this stage.
Basically there are two symptoms.
1) A rattle when idling that disappears when the clutch is pressed.
2) A rattle when accelerating in 5th and 6th.

This rattle started soon after I had an MYP gearbox and new clutch fitted. We assumed it was a bearing in the gearbox. I then purchased a PTU gearbox (from a 2014 Audi A3 1.6 tdi 6-speed manual with 47078 miles).
When fitting the audi A3 gearbox we found the clutch slave cylinder had also failed so we replaced that and the clutch as it had fluid on it.
Annoyingly the sounds are exactly the same. A rattle when idling and a rattle when accelerating but only in 5th and 6th.

Im hoping someone may be able to suggest something. Id particularly welcome any feedback from anyone who fitted an MYP or other 6 speed box to an AMF, even if just to say it's working fine for them.

The sound was recorded in the cabin. It's not easy to hear when outside due to the noise of the engine.

P.S. (there's a microswitch or something gone in the door so thats the clicking on restart at 33sec. Ignore that)
Audio begins with clutch pressed.
Clutch released at about 2sec and pressed again at 7sec, released at 10.
listen to the sound here

Any ideas greatly welcomed.
N
Hi it sounds to me a bit induction related strangely, possibly a dislodged charge pipe or a misplaced vac/ air line.
Hth
Keith.
 

Menno

A2OC Donor
Did you install a DMF and clutch or kept the single mass flywheel and clutch?
Some people changed their DMF to SMF on vag Tdi's and the result was "gear rattle" from the gearbox.
PTU and MYP are standard used with DMF (as far as I know, could be wrong here).

If you used a DMF on your AMF, then I don't have a clue what's going on.
Now and then I have a light rattle too on my AMF when idling, but disappears when the clutch is pressed one time.
 
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dj_efk

A2OC Donor
As I indicated in my earlier reply, it does sound like a gearbox issue - But I'm not sure in @Menno is on to something here on not, as plenty of others have installed the six speed gearboxes, including MYP and PTU, and have not reported any such noise despite also running single mass flywheels.

Again as per my previous post, you really need to identify exactly where the noise is originating from, with the car up on stands or on a ramp so you can get under there with a stethoscope.
 
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nick4tl

Member
Hi.
@dj_efk good idea re stethoscope. Nothing obviously rubbing. Odd that it vanishes when clutch pressed if it were just something loose.
@A2Z alternator got a new pulley and tensioner a few weeks back too.
@ menno: We stayed with single mass flywheel. That is a thought.
@kp115: could that give the clutch dependent nature of the noise though I wonder?
@dj_efk: roger that re stethoscope. Im praying its not another dodgy box.
Thanks for all suggestions so far everyone.
N
 
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timmus

A2OC Donor
Just a thought...
This family of 6-speed gearboxes are all designed for cars with DMFs, and therefore have a bell housing that's deep enough to accommodate a DMF. If only a SMF is fitted, the clutch plate will be at the extreme end of the gearbox's input shaft. What do we think about that, folks? Can we marry that with the symptoms described?

Cheers,

Tom
 

nick4tl

Member
Car goes back on lift on Monday. Mechanic buying a stethoscope too.
It would be good to hear from anyone who has put one of these 6 speed boxes on an AMF for sure.
Also if anyone had an idea of the dimensions of the dmf and smf to compare thickness that would be handy too I guess.
I’ll be sure to update here if any developments.
 

nick4tl

Member
We are baffled. I changed the shoe and small white bushes on the shift arms yesterday as they were worn. The rattle at idle persists even when the gear cables are disconnected and the shift arms removed from the tower. Its also there when in gear and driving but much less noticeable. I could hear it yesterday when slowing down in gear.
Reading on the tdi forums it seems gearbox clatter in idle is common when the DMF is on the way out but normally not present when these cars are converted to SMF. I have a single mass flywheel already so not really sure whats going on.

I've not come up with any ideas on the rattle when accelerating that is only present in 5th and 6th gear.
Driving in 1st to 4th, even when pushing it, the engine seems perfectly fine and smooth. Much improved since the engine mounts and oil chain were all replaced and the turbo reconditioned.

The plan now is to change the clutch. again. It has a teckmarx clutch kit in it (cheap!). This was fitted new with the PTU as the fitted plate had gotten clutch fluid on it from a leaking slave cylinder. The exact same teckmarx kit was fitted when the MYP was fitted. Thats now going to be swapped for a LUK.
The breaker that sold me the PTU will supply another gearbox under warranty. We'll have that on the ready in case the clutch doesn't solve the issues.

fingers crossed.
 

Rusty911

A2OC Donor
We are baffled. I changed the shoe and small white bushes on the shift arms yesterday as they were worn. The rattle at idle persists even when the gear cables are disconnected and the shift arms removed from the tower. Its also there when in gear and driving but much less noticeable. I could hear it yesterday when slowing down in gear.
Reading on the tdi forums it seems gearbox clatter in idle is common when the DMF is on the way out but normally not present when these cars are converted to SMF. I have a single mass flywheel already so not really sure whats going on.

I've not come up with any ideas on the rattle when accelerating that is only present in 5th and 6th gear.
Driving in 1st to 4th, even when pushing it, the engine seems perfectly fine and smooth. Much improved since the engine mounts and oil chain were all replaced and the turbo reconditioned.

The plan now is to change the clutch. again. It has a teckmarx clutch kit in it (cheap!). This was fitted new with the PTU as the fitted plate had gotten clutch fluid on it from a leaking slave cylinder. The exact same teckmarx kit was fitted when the MYP was fitted. Thats now going to be swapped for a LUK.
The breaker that sold me the PTU will supply another gearbox under warranty. We'll have that on the ready in case the clutch doesn't solve the issues.

fingers crossed.
When the clutch comes out, assuming the friction plate is the sort with 'sideways' springs, just see if they're all loose, plus compare it to the LUK clutch.

Effectively this was the system used before DMF but for the same reasons, to smooth out the impulses from the engine to prolong transmission life and reduce NVH generally I believe.

If you were to consider changing the box, I'd want to side-to-side them in all regards: input shaft play, with in gear is there any difference in back-lash on both input shaft and output flanges? Generally just compare everything with clutch and gearbox as you might have an 'aha!' moment where one has some backlash (or noise of some sort) and the other doesn't.

The ideal is not only you resolve the noise but you know why you've resolved the noise. Imagine if the noise goes without knowing why. 'Brilliant!', I don't know how, but it's sorted'. If that noise gradually came back over a fortnight say, you're not much better off, esp if two major parts were changed at the same time (clutch / gearbox in this case).

Anyway, cheap clutches can give a whole world of really odd issues, so that'll be a great one to cross off. As @timmus has mooted, it'd also be interesting to see how the various depths stack up whilst you're in there.
 
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Rusty911

A2OC Donor
BTW, be wary of changing the gearbox unless you can definitely prove the one you've fitted is faulty. You know it selects O.K., sounds like it's not whining. If there doesn't seem to be any weird backlash, a sample of oil drops out nice and clean and generally looked like no-fault-found, you'd want a good reason to change it out.

The last thing you want is to sort out one problem and risk starting a new one! 🙂
 

nick4tl

Member
It was the clutch! Both teckmarx clutch kits that were fitted (one with MYP and then another with PTU) were the same it seems. I now have a valeo clutch fitted and all seems fine (I would have preferred LUK but we couldnt get it quickly and I need the car back on the road)
Ive gone back to the MYP box as the car dismantlers may take the PTU box back. If not I've potentially got a PTU box for sale that I now know to be good in condition.
Anyway, just back from an hours drive and the car is transformed following all the work over the past few months.
Thanks for all the support from here. Particularly to Steve(@A2Steve) and Andy (@Clackers) for sorting me out with some tricky to source parts.
 
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