Shudder when slowing down

[Silver Caravelle]

G'day Greg,

Thanks for the response.

Amongst many things, I have inspected the whole exhaust, banged and clattered it, checked for touch points (appear to be none hot or cold), loosened and tightened exhaust hangers and mount (near flex pipe ) to the chassis, moved the flex pipe back and forth in case it is was binding. DPF well who knows - it feels solid with no rattles. I have also got out spanner and tightened all heat shield bolts underneath including all the plastic cover(s) smaller bolts underneath.

But it is worth rechecking again including undoing the exhaust hangers to relieve a little tension to see if this changes the vibration/resonance, or the wire trick as you have suggested. Notably the exhaust hangers do not have a lot of give.

Good advice regarding getting an AUTO place to do a full assessment.

I am a little sus on the auto and over run vibration and possible tinny noise/rattle and vibration potentially from this vicinity.

And unless one of the engine mounts has softened enough to cause this grief. But short of swapping these out, these seem ok as best as I can ascertain loading then up in drive and reverse and visual inspection and feel when engine is running.

Given this all started about 10,000ks ago and its only up to 23K its a bit of a worry for such low kms. Prior to that I was impressed with the general smoothness.

Dam I should have contacted you when I was in Canberra last week! If there is any one in Melbourne who wouldn't mind comparing their vehicle, I would be very grateful, and feel free to PM me.

Cheers,

Scott

[Silver Caravelle]

What car is it Mr Caravelle? T4 or T5?

On a T4, I would check the rear engine mount on a hoist. The one behind the gearbox. They wear the rubber and get horrid vibration when slowing down.

Golf Loon, its a T5 Multivan TDI 6 speed auto. My previous vehicle was a T4 Caravelle (hence the 'old' Silver Caravelle login name).

I had all mounts changed on the T4. Made a big difference at the time.

One would think it is unlikely to be the mounts on a T5 for such low ks. But anything is possible I suppose. The rear one in particular might have softened or separated enough to cause the problem. But feels OK when fully loaded up.

Stay tuned.....

Cheers,

Scott

[Silver Caravelle]

Dear all,

I spent a lot of time over the weekend looking into this.

Have ruled out the exhaust at this stage, by loosening the bolts and flexing the resonator a little and running the engine in this state. No change.

Engine mounts seems fine. The engine does not move much when revving. And there is very little vibration under full acceleration. There is some vibration at 1800 rpm and off idle but put this down to natural harmonic vibration - and the fact that this is a 5 cylinder. This is in addition to the drone at judder at 1400 rpm explained below....

Got the garden hose (stethoscope) out and played doctors with the engine. There two things going on I think:-

1. Drone noise from auto transmission pan at exactly 1400 RPM. If you push on the pan it slightly with your hand it mostly goes away. There is quite a bit of buzz (may be normal?) from I would imagine is the solenoid pack internally. Further investigation required from a professional.

I have also established this is the exact same revs I get from what I am currently assuming is torque converter judder when slowing down to a standstill. Once again it is exactly at 1400 RPM each time and is more prominent after a reasonable drive with the transmission fully warmed up. If one slows down quickly it goes through this rev range quickly and not judder is felts. If one slows down very slowly so that it coasts through the 1400 rpm, the judder is felt.

2. There is tinny rattling gushing (?) sort of faintish noise from either the water pump area or transmission area. It is an internal noise. But could be perhaps just PD injection noise? Or possibly transmission TQ flex plate or water pump? But sort of doubt it is the water pump.

So this is where it is at. But with these sorts of vagaries, it may be difficult for the dealer to run with it....and might just get the standard sort of ' this is normal' response. Therefore an independent professional assessment is definitely warranted.

Outside of this, there is some drone when lugging along at the 1400 rpm range in particular. And will be related to the above issues.

If any body in Melb with a T5 128 kw auto is available, I would be grateful of some time to compare noises!

Thanks,

Scott

[gregozedobe]

2. There is tinny rattling gushing (?) sort of faintish noise from either the water pump area or transmission area. It is an internal noise. But could be perhaps just PD injection noise? Or possibly transmission TQ flex plate or water pump? But sort of doubt it is the water pump.

If any body in Melb with a T5 128 kw auto is available, I would be grateful of some time to compare noises!

Scott,

Good on you for persisting, I hope you get there in the end.

If you are getting the "tinny rattling gushing" noise on over-run you can probably eliminate PD injection noise as the cause - until the engine gets close to idle revs the injectors don't inject any fuel at all and so are very quiet (that's why the MFD will display fuel consumption of 0.0 l/100km on the over-run). I can actually tell how steep a hill is by how much noise the injectors make as I go up it (I call it the "warble" of a working 5 cylinder TDI - sad, I know ).

If you can't locate a 128Kw auto an audio comparison with a manual 128Kw van will probably still be useful, as it may tell you whether the noise you are hearing is coming from the engine or not.

[Silver Caravelle]

Scott,

Good on you for persisting, I hope you get there in the end.

If you are getting the "tinny rattling gushing" noise on over-run you can probably eliminate PD injection noise as the cause - until the engine gets close to idle revs the injectors don't inject any fuel at all and so are very quiet (that's why the MFD will display fuel consumption of 0.0 l/100km on the over-run). I can actually tell how steep a hill is by how much noise the injectors make as I go up it (I call it the "warble" of a working 5 cylinder TDI - sad, I know ).

If you can't locate a 128Kw auto an audio comparison with a manual 128Kw van will probably still be useful, as it may tell you whether the noise you are hearing is coming from the engine or not.

Greg, Thanks for the feedback.

The "tinny rattling gushing" noise appears to eminate from the transmission or water pump area and can be heard with the head under the bonnet at idle and is a separate noise to the juddering noise and vibration at 1400 rpm on overrun. But may the cause may ultimately be the same. At this stage my money is on the auto transmission.

I am drafting an email to the dealer to fully document the observations and for a thorough investigation. If it takes days of road testing then they can have it for as long as necessary as I don't want it back until it sorted.

Thanks again.

Regards,

Scott

[Transporter]

Greg, Thanks for the feedback.

The "tinny rattling gushing" noise appears to eminate from the transmission or water pump area and can be heard with the head under the bonnet at idle and is a separate noise to the juddering noise and vibration at 1400 rpm on overrun. But may the cause may ultimately be the same. At this stage my money is on the auto transmission.

To check if the noise is from the water pump you could easily remove water pump cover - held by 3 bolts (no need for new gasket, just smear a bit of oil on that rubber gasket before you refit the cover) and try to move the water pump gear by pushing on the edge of the gear, if the water pump bearing is worn out the gear would be bouncing on the other 2 gears there. If that would be the case you can expect the coolant leak soon!

[Silver Caravelle]

To check if the noise is from the water pump you could easily remove water pump cover - held by 3 bolts (no need for new gasket, just smear a bit of oil on that rubber gasket before you refit the cover) and try to move the water pump gear by pushing on the edge of the gear, if the water pump bearing is worn out the gear would be bouncing on the other 2 gears there. If that would be the case you can expect the coolant leak soon!

Thanks Transporter, that's an interesting point regarding the water pump and very good picture. I have just sent a detailed email to the dealer regarding my concerns prior to booking it in for a thorough investigation. At least it is now detailed in writing as a potential reference source for the service guys when they are investigating. A five minute chat doesn't convey things in detail and is open to misinterpretation of what is actually occurring.

I will report back on the findings.

Cheers, Scott

[Tornado T5]

If any body in Melb with a T5 128 kw auto is available, I would be grateful of some time to compare noises!

Thanks,

Scott

Scott, would love to help however I'm away in a day and back end of Jan. Hopefully it's rectified before then, if not remind me with a PM and I'll see what we can do.

[Silver Caravelle]

Scott, would love to help however I'm away in a day and back end of Jan. Hopefully it's rectified before then, if not remind me with a PM and I'll see what we can do.

Tornado, much appreciated.

Best Regards,

Scott

[4wheels]

Hi Scott,

You're also welcome to compare 'notes' with me, but mine's a manual 4 Motion.
I'm in Fairfield, where are you? Any-way I'll be around the next few days. Call me on 9481 5673 to arrange if you wish.

Brian
2007 Trakkadu.