Grinding/Vibrating noise under de-acceleration

carstensdj

carstensdj

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Hey fellow forumites,

Was hoping someone might be able to shed some light on this issue for me...

I've just spent R10k on servicing my '05 Polo Trendline. I had a new Clutch Kit installed as well as a major service done. Car feels smoother but now have another issue that wasn't there before the service...

I've noticed that if i'm in 2nd or 3rd gear, go up to just over 4000rpm and then take my foot off the accelerator, there is a fairly loud grinding/vibrating type noise coming from the engine bay. The best way I can describe the sound is it sounds like an exhaust heat shield vibrating against the branch or something like that, but it's not that...

The mechanic reckons that the noise couldn't be heard before because the clutch was very worn and not biting properly. Now that there is a new clutch, it's gripping the gears properly and that the issue is more than likely with the gearbox.

I had to make a loan for that R10k which is being paid back on a monthly basis and I really don't have more money to just throw at this. Really hoping that someone else might have experienced something similar after a clutch change or in general and might have answers instead of me paying hours worth of labor to MAYBE find what the issue is.

Feel like every time my car goes near a mechanic i'm just buying myself months of worry, stress and debt. It just never seems to be a good experience for me :cry:

Thanks for any advice or help guys and gals.
 
carstensdj said:
The mechanic reckons that the noise couldn't be heard before because the clutch was very worn and not biting properly. Now that there is a new clutch, it's gripping the gears properly and that the issue is more than likely with the gearbox.
Click to expand...

Hehe, with a statement like that from the mechanic I would search for a new mechanic ASAP.
 
Is the sound there when changing at the non drag racing rev range?
 
bandooq said:
It's related to the gearbox. You did say you had the clutch replaced. Take it to another mechanic for a 2nd opinion.
Click to expand...

Correct, new clutch has just been fitted. Unfortunately I had to take out a loan just to get this R10k service done so going to yet another mechanic and paying them labor fees to take shots in the dark at what it MIGHT be isn't really an option for me right now. That's why I was hoping someone here might have knowledge of this and could point me in the right direction...
 
Strange, what did the major service entail? It does look like there might be an issue in the gearbox, was the brake fluid and transmission oil checked and renewed?
 
WaxLyrical said:
Does it make any noise when depressing clutch and changing gears?
Click to expand...
I don't think so but it's hard to say as when one presses the clutch, as you know, the revs drop rapidly and the second it's less than 4000rpm the vibration/noise just completely disappears... I'm out on the road shortly so will test a few times and see what I find
 
carstensdj said:
I don't think so but it's hard to say as when one presses the clutch, as you know, the revs drop rapidly and the second it's less than 4000rpm the vibration/noise just completely disappears... I'm out on the road shortly so will test a few times and see what I find
Click to expand...

Could also be nothing to do with the gearbox but engine mountings or something related with the change in load when you decelerate.
 
thechamp said:
Strange, what did the major service entail? It does look like there might be an issue in the gearbox, was the brake fluid and transmission oil checked and renewed?
Click to expand...

All fluids and filters were changed, brakes adjusted, new clutch kit fitted, flywheel skimmed, new plugs and leads, new breather pipe to the intake, new water housing (old one had a small crack in it).

Just strange to me that the noise never existed before the car went in, and now it's there after the service. Mechanic reckons it's because the clutch is now gripping (for lack of a better term) the gears properly and that's what's causing a vibration in the gearbox itself.
 
carstensdj said:
I don't think so but it's hard to say as when one presses the clutch, as you know, the revs drop rapidly and the second it's less than 4000rpm the vibration/noise just completely disappears... I'm out on the road shortly so will test a few times and see what I find
Click to expand...

Just give a service centre a call explaining your problem, they should be able to tell you what could be wrong.
 
carstensdj said:
All fluids and filters were changed, brakes adjusted, new clutch kit fitted, flywheel skimmed, new plugs and leads, new breather pipe to the intake, new water housing (old one had a small crack in it).

Just strange to me that the noise never existed before the car went in, and now it's there after the service. Mechanic reckons it's because the clutch is now gripping (for lack of a better term) the gears properly and that's what's causing a vibration in the gearbox itself.
Click to expand...

Go through the engine bay and check everything yourself, don't just take their word for it. Pay particular attention to the engine mountings, it is possible that they might have forgotten to tighten up something properly and there us something that is coming into contact with something. It is even better to have someone in the car revving it up and you check engine movements and sounds.

Also check the fluids as well. The mechanic's story does not make sense.
 
thechamp said:
Go through the engine bay and check everything yourself, don't just take their word for it. Pay particular attention to the engine mountings, it is possible that they might have forgotten to tighten up something properly and there us something that is coming into contact with something. It is even better to have someone in the car revving it up and you check engine movements and sounds.

Also check the fluids as well. The mechanic's story does not make sense.
Click to expand...

I was thinking engine mountings also... yes check the engine movement on revving. It's common for these to go when mechanics jack up the engine, but then they were close to end of life anyway.
 
WaxLyrical said:
Does it make any noise when depressing clutch and changing gears?
carstensdj said:
I don't think so but it's hard to say as when one presses the clutch, as you know, the revs drop rapidly and the second it's less than 4000rpm the vibration/noise just completely disappears... I'm out on the road shortly so will test a few times and see what I find
Click to expand...
Click to expand...

Just drove and tested while depressing the clutch and it doesn't seem to make the noise or be as bad when the clutch is engaged
 
thechamp said:
Go through the engine bay and check everything yourself, don't just take their word for it. Pay particular attention to the engine mountings, it is possible that they might have forgotten to tighten up something properly and there us something that is coming into contact with something. It is even better to have someone in the car revving it up and you check engine movements and sounds.

Also check the fluids as well. The mechanic's story does not make sense.
Click to expand...

GoB said:
I was thinking engine mountings also... yes check the engine movement on revving. It's common for these to go when mechanics jack up the engine, but then they were close to end of life anyway.
Click to expand...

Thanks for the suggestions guys, will test this and take a look. Engine mountings were definitely not in great shape... That I do know. There was a bit of movement and rocking when revving so maybe that's what it is.
 
That mechanic is a moron. I would not let him touch my mates car with a 6 foot pole. He is talking ***.

Take it back. He could have broken engine mounts. wrong clutch fitted. something not tightened properly.
 
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