Manual i30 diesel transmission thump...

terry hunter · **February 19, 2010, 10:44:17**

This is the first front wheel drive I've owned and have been told by two service centre mechanics that there is nothing to worry about.

Does any other manual i30 driver notice that when you change gears... either quickly or slowly... that the transmission gives a good thump as you take foot off clutch and onto accelerator again...as when one changes gear? If done very very slowly and smoothly I can avoid it but not in normal driving.

I've taken two mechanics for a drive and they seem to have trouble even hearing what I hear! But it is so obvious to me and to others I've had travelling - especially loud in the back seat- that it does not sound normal to me.

Could it just be normal front wheel drive torque/stress on the driveshafts and or engine mounts that I have to get used to?

I can't see why these Hyundai techs. would fob me off if there was work in it for them under warranty. The car has done 17000km and has been noticable to me from the first couple of weeks driving. I'm not sure it's getting worse but it sure isn't improving as time goes on.
Am I hearing things... is this normal...?

Terry H

StarSeeker · **Reply #1: February 19, 2010, 18:29:08**

Does it do it only when you change gears, would it do it if you put your foot down hard, for instance in second gear

Also what gear changes does it mostly do it in

Dazzler · **Reply #2: February 19, 2010, 21:12:16**

Can't say i've noticed it in mine.. very frustrating for you..

I'm thinking clutch or drivetrain more so than gearbox as such...

terry hunter · **Reply #3: February 19, 2010, 22:14:27**

Quote from: StarSeeker on February 19, 2010, 18:29:08

Does it do it only when you change gears, would it do it if you put your foot down hard, for instance in second gear
Also what gear changes does it mostly do it in

Hi Starseeker... only when changing gear... all gears but most noticeable 1st to second, second to third. Putting foot down hard does not do it.

terry hunter · **Reply #4: February 19, 2010, 22:19:27**

Quote from: Dazzler on February 19, 2010, 21:12:16

Can't say i've noticed it in mine.. very frustrating for you..

I'm thinking clutch or drivetrain more so than gearbox as such...

G'day Dazzler,

It is much more noticeable when sitting in the back seat. My missus asks even when she's driving (and she's a bit harder on the clutch than me) "Why does it do that?".... and she's not tuned in at all to car noises so it's pretty obviously there.

I can't understand why the techs have so much trouble hearing the issue.

Terry H

Shambles · **Reply #5: February 19, 2010, 22:28:48**

Quote from: terry hunter on February 19, 2010, 10:44:17

I've taken two mechanics for a drive and they seem to have trouble even hearing what I hear!

Did they drive it themselves or as passengers?

You need a 3rd opinion on this. It doesn't sound right to me.

terry hunter · **Reply #6: February 20, 2010, 02:10:55**

Quote from: Shambles on February 19, 2010, 22:28:48

Quote from: terry hunter on February 19, 2010, 10:44:17

I've taken two mechanics for a drive and they seem to have trouble even hearing what I hear!

Did they drive it themselves or as passengers?

You need a 3rd opinion on this. It doesn't sound right to me.

They did both but only for a short run .... but I could still hear it when they were driving and had trouble hearing it.

My hearing is not that good either! but perhaps theirs is worse.

Terry H

LuciferDarklord · **Reply #7: February 20, 2010, 03:54:35**

Could be engine mounts. I've had them fail on me in a few FWD cars, mainly because I was abusing them (old civic and wife's Daewoo). The torque reaction of the engine/gearbox makes the whole assembly move on the mounts, causing a thump. Generally it is worse when you change quickly rather than slowly - so not sure if this could be your problem.

Blue · **Reply #8: February 20, 2010, 04:44:07**

Quote from: LuciferDarklord on February 20, 2010, 03:54:35

Could be engine mounts. I've had them fail on me in a few FWD cars, mainly because I was abusing them (old civic and wife's Daewoo). The torque reaction of the engine/gearbox makes the whole assembly move on the mounts, causing a thump. Generally it is worse when you change quickly rather than slowly - so not sure if this could be your problem.

I had a mini did this once due to broken engine mounts, sounds like a good starting point to me... too early for busted CV joints.

terry hunter · **Reply #9: February 20, 2010, 05:19:28**

Engine mount seem to be a possibility I suppose. What actually fails with engine mounts if they are pretty well new? Have they not been tightened enough? can one have a broken engine mount from new?

LuciferDarklord · **Reply #10: February 20, 2010, 05:43:56**

I'm not sure I guess one could have had a manufacturing fault? I think these days some of them are fluid filled to reduce vibration. I used to test my Civic by opening the bonnet, looking under the bonnet gap to see the engine while sitting in the driver's seat and moving a metre or so in the driveway and seeing how far the engine 'rotates' on the mount. Unless you have a good i30 to compare to it will probably always look like its moving too much tho.

Blue · **Reply #11: February 20, 2010, 07:21:34**

Quote from: terry hunter on February 20, 2010, 05:19:28

Engine mount seem to be a possibility I suppose. What actually fails with engine mounts if they are pretty well new? Have they not been tightened enough? can one have a broken engine mount from new?

Hard to tell without seeing it or hearing it... but I would think it could be any / a combination of the above.
With limited information / experience with it, the cause could also be a full drink can rolling around under the passenger seat !!!!!!!

(A review team have recently reported something similar with a KIA, only to find the REAL cause - the can !)

I do hope you find it / get it fixed soon though.

StarSeeker · **Reply #12: February 20, 2010, 09:16:23**

Hi terry hunter

You wondered whether it may be the transmission but say the noise is most noticeable in the back of the car. Without hearing it myself I can't comment, but could it be something like the exhaust moving around and hitting the underneath of the bodywork? Maybe you only assume it's the transmission because it only happens when you change gear, but changing gear will cause other parts of the car to jolt.

Think I would be tempted to concentrate on the back end of the car and take it to another dealer to be checked over. Also to check the car over properly, they would need to get it on the ramps.

You assumed the dealer would want the work and is not likely to fob you off, well they may want the work but only if the fault is easy to diagnose in my opinion. My experience leads me to believe that the dealerships seem to be too scared to make a decision on a repair in case they get it wrong and have to foot the bill, I suppose if they don’t get it right, Hyundai may refuse to pay out anymore money and tell them it is there fault for an incorrect diagnosis. There are a lot of examples on this forum where members still have issues that have not yet been resolved and that is because the dealership has not been able to get a positive diagnosis in my opinion.

terry hunter · **Reply #13: May 22, 2010, 12:09:17**

Well I've had two dealerships check the car out now (twice to one place) and none of them says anything is abnormal.

While this is comforting in one way, I'm very disappointed and I suppose I'll have to ignore it till I can drive another manual to see if it's a standard thing. The last lot had it for a whole day to check it out and they checked the suspension and the engine mounts.
I wish it was a can under the seat.

While it is most noticeable in the rear, it is still obvious when in the drivers or passengers seat.

Can nobody else confirm that their manual is perfectly smooth and quiet when changing gears?... that there is no perceptible thud or thump when letting the clutch out?.... even at a slow or moderate pace gear change?....

This issue is the only real thing that would make me not recommend the i30 (manual) to someone else if indeed it is a "normal" thing.

Thanks for your replies.

Terry

By the way... I just did a rough economy run with it over mixture of flat and quite hilly terrain... I'm quite pleased with the 4.76lt per 100k.

This is the i30 wagon... still cool day... mostly kept at 85-90kph.... music up very loud... (mostly Porcupine Tree).

Dazzler · **Reply #14: May 22, 2010, 12:18:03**

Hi Terry..

Three months and still no further advanced..

I have driven my i30 Crdi in all sorts of conditions (and often drive without music) still haven't noticed a clunk or a thump from the drivetrain...

If only you could catch up with one of our members with a similar car. You experience theirs and have them experience yours (to me it is about the only way to get this sorted)

Any takers???

terry hunter · **Reply #15: May 22, 2010, 12:22:13**

Thanks Dazzler... I'm in Bendigo... central Vic.

Terry

2i30s · **Reply #16: May 22, 2010, 12:25:27**

ozsnowman lives in bendigo,[or swan hill] is his car a crdi.?

Dazzler · **Reply #17: May 22, 2010, 12:29:30**

Stew I think his first name is .. yes he has an SX Crdi hatch..

He is a pretty easy going fella. If he doesn't see this thread I suggest you PM him and organise to catch up

Shambles · **Reply #18: May 22, 2010, 12:31:42**

Hi Terry. This has gone on long enough I reckon.

Do you have any independent assessors around your neck of the woods? Over here we can call on our emergency assist groups (AA etc) to assess a vehicle, usually prior to purchase. Here, at a small cost, we can get a completely impartial report on the state of a car.

2i30s · **Reply #19: May 22, 2010, 12:35:54**

racv or vacc can do those tests.

eye30 · **Reply #20: May 22, 2010, 12:36:50**

Quote from: terry hunter on May 22, 2010, 12:09:17

that there is no perceptible thud or thump when letting the clutch out?.... even at a slow or moderate pace gear change?....

My understanding is the Thud may be associated with the release bearing.

Did they mention this as a possible cause of the noise

Dazzler · **Reply #21: May 22, 2010, 12:39:22**

Just had a thought .. maybe terry is THUMPER under a pseudonym..

2i30s · **Reply #22: May 22, 2010, 12:41:20**

you are a naughty boy dazz.

Doggie 1 · **Reply #23: May 23, 2010, 14:07:16**

I have a diesel manual and have no noises such as you have described, so it isn't normal.

Lorian · **Reply #24: May 23, 2010, 15:10:10**

Like starseeker said, Don't overlook the fact the noise seems louder in the back. Are you sure it's not the tailgate banging (poort stop adjustment) or something loose in the boot like spare wheelnuts),

**Reply #25: May 24, 2010, 06:32:17**

I can induce a thump if I let the clutch out a little too quickly. In fact it will readily and noticibly thump if I engage it with barely too many revs on. If on the other hand, I drive sedately and use the clutch respectfully and gently, it is as smooth as honey; best clutch feel I've ever had. It never complains (apart from the subdued "thump") nor slips if I'm a little clumsy with the timing.

It seems to me like it's a design compromise and has been designed to be smooth, if you are, and less happy if you treat it harshly, else it has just turned out that way.

The thump I'm referring to is clearly from the clutch itself. It's as if the springs in the driven plate are a little soft.

Having said that, it definitely doesn't lend itself to boy racer abuse.

terry hunter · **Reply #26: May 24, 2010, 13:54:30**

Quote from: eye30 on May 22, 2010, 12:36:50

Quote from: terry hunter on May 22, 2010, 12:09:17
that there is no perceptible thud or thump when letting the clutch out?.... even at a slow or moderate pace gear change?....

My understanding is the Thud may be associated with the release bearing.

Did they mention this as a possible cause of the noise

No, not a mention of this.

terry hunter · **Reply #27: May 24, 2010, 13:56:00**

Quote from: Dazzler on May 22, 2010, 12:39:22

Just had a thought .. maybe terry is THUMPER under a pseudonym..

... or I've accidentally run over THUMPER who is now caught up under the car...............

terry hunter · **Reply #28: May 24, 2010, 13:58:01**

Quote from: Lorian on May 23, 2010, 15:10:10

Like starseeker said, Don't overlook the fact the noise seems louder in the back. Are you sure it's not the tailgate banging (poort stop adjustment) or something loose in the boot like spare wheelnuts),

I can guarantee it is nothing rattling, banging or loose. It is definitely a muffled "thump" just on gear changes as the clutch is released... either with quick changes or slow changes.

terry hunter · **Reply #29: May 24, 2010, 14:01:56**

Quote from: Pip on May 24, 2010, 06:32:17

I can induce a thump if I let the clutch out a little too quickly. In fact it will readily and noticibly thump if I engage it with barely too many revs on. If on the other hand, I drive sedately and use the clutch respectfully and gently, it is as smooth as honey; best clutch feel I've ever had. It never complains (apart from the subdued "thump") nor slips if I'm a little clumsy with the timing.

It seems to me like it's a design compromise and has been designed to be smooth, if you are, and less happy if you treat it harshly, else it has just turned out that way.

The thump I'm referring to is clearly from the clutch itself. It's as if the springs in the driven plate are a little soft.

Having said that, it definitely doesn't lend itself to boy racer abuse.

If it only happened when I worked it hard, I'd be more understanding and forgiving. But it is almost impossible to prevent it unless I get perfect revs and ease the clutch out so there is no grab on the clutch at all. This is a ridiculous way to drive of course.
Perhaps the clutch plate has a weak spring or a broken one?