Worrying knocking noise on my Cupra TDi 150

[Dyscontinued]

Had this posted in the Mk1 forum but was suggested I post it here too, so,

Over the past week I've noticed a strange knocking type noise coming from where I think the gearbox and clutch are, getting worse this past couple of days.

At first it doesn't make the noise when under heavy acceleration but at first only when coasting in any gear or stood at the lights when not in gear at all.

Over the past couple of days it's gotten more noticeable, and it's when in any gear under very slight acceleration at the very beginning of that gear ie, in 3rd at 20mph, 4th at 30mph, 5th at 40mph.

Please anyone any ideas?

On a slightly related note, that's always how I've driven my petrols, they'd hit 2000 revs and I've change gears, in all the cars it was at the above speeds in those gears.
When I got this I just figured with the extra talk I'd just keep changing at those speeds and keep more economical.
Should I not be doing that? Should I still be waiting til 2000rpm as opposed to the speeds?

 

[thebeno]

My car (same as yours) is more economical at 3k revs than 2k revs, diesels are high torque (not talk) so driving at low revs will reduce your life of clutch, never floor it under 2.5k revs

 

[devonutopia]

Sounds like flywheel vibration to me. It doesn't like being subjected to the low down torque. I recommend not using full power (if much power at all) until 2000rpm. If your flywheel is on the way out, it will need replacing fairly soon.

 

[Dyscontinued]

I never floor it til further up the range, I'll start changing later in general though.

Flywheel sounds a lot cheaper than a whole new clutch. Any suggestions on what to change it for? Another OEM one or is there more....sturdy solutions available?

Any of these any good? http://www.vwspares.co.uk/leon_clutch.php

 

[thebeno]

Sachs is very well liked, guaranteed up to 400 big ones of torque, then you can have a big fat remap!!

 

[Dyscontinued]

hehe so I've read

Do I need a whole Sachs clutch though or will just the flywheel do?

As much as a remap capability appeals I do need the cheapest option.

 

[slick]

You want a single mass flywheel and sach clutch.. costs about £1200 fitted abouts,
Or a helix and single mass fly, sumthing about £900 for it?

Devon if you can correct me if I'm wrong?

 

[Dyscontinued]

How do those prices compare to an OEM replacement?

 

[thebeno]

Think Awesome do sachs for £700??

 

[glynnd]

Before you start forking out for a clutch and single/dual mass get the gearbox mountings checked out. I am sure I have been told at some time that the cupra is prone to gearbox mounting failure. Mine has had a new engine mounting replaced at 60k under warranty. Incidentally it was the mounting by the cambelt cover.

 

[UncleFester]

My flywheel AND clutch almost fell out at 36k miles - i don't boot mine in higher gears at low rpm - it's always been driven through the gears ( might explain rotten mpg ) anyway an OEM flywheel is £300 + vat, clutch is £140 or so and labour is 4 ish hours at whatever the garage charge - MK Seat charge almost £85 per hour .....

Makes a SACHS or HELIX upgrade look almost good value

 

[Dyscontinued]

Cheers guys.

My usual mechanic/autoelectrician is going to have a look for me.

As much as I'd love a remap and nice strong clutch, if it's such a massive price difference I don't think I'm gonna be able to justify not getting OEM

 

[UncleFester]

If the flywheel has gone and the clutch needs replacing, even with 'cheapo' rates you're looking at £200 labour!

£300 for DMF
£140 for clutch
£200 for labour

Possibly + vat ......

That's almost 700 quid, you can get a clutch that will take all you'll ever throw at it for a stones throw more, i would suggest you can't afford not to do it - bearing in mind when the obligatory remap comes you'll only kill another stock clutch and have to fork out again.

 

[Dyscontinued]

Does the Sachs clutch fitting inclde a flywheel?

Sorry I'm really dumb!

 

[devonmikeyboy]

Sachs is very well liked, guaranteed up to 400 big ones of torque, then you can have a big fat remap!!

No it`s not. Sashs organic clutch max torque is 340lb, Helix organic clutch 380lb.

Does the Sachs clutch fitting inclde a flywheel?

Sorry I'm really dumb!

You can get a single mass flywheel if you want but you have to pay extra and it will create vibration and noises problems plus you don`t need one unless your car is heaverly tuned as a DMF is alot better. I am running 440lb torque with a DMF.
To uprate a clutch;
Cheapest is to just buy the pressure plate as thats the first weak link. Best is to buy the pressure plate and friction/drive disc.

 

[Dyscontinued]

Just an update on this, took it to my mechanic mate but it was rainging that day and the noise stopped, it's not done it since.

 

[horace1664]

You can get a single mass flywheel if you want but you have to pay extra and it will create vibration and noises problems plus you don`t need one unless your car is heaverly tuned as a DMF is alot better. I am running 440lb torque with a DMF.
.

Just to clarify, if your DMF failed would you replace it with another OEM DMF?
James

(I just love the TLAs on this site!!)

 

[devonmikeyboy]

Just to clarify, if your DMF failed would you replace it with another OEM DMF?
James

(I just love the TLAs on this site!!)

Yes unless it is highly tuned ie 230bhp+ then you might go SMF.

 

[horace1664]

Just to clarify, if your DMF failed would you replace it with another OEM DMF?
James

Yes unless it is highly tuned ie 230bhp+ then you might go SMF.

Thanks for that, how long do DMFs last in your car?

Is the life greatly reduced?

I'm trying to plan ahead for if the transmission has to come off before the end of the waranty (only two year in Spain).

If it does I'm thinking of a decent clutch and torque biasing differential (Peloquin) as I hate what traction control system must be doing to an open differential!

After that a Hybrid Turbo me thinks.

It's a bit in reverse to the way most people do things but why not?

James

 

[devonmikeyboy]

Thanks for that, how long do DMFs last in your car?

Is the life greatly reduced?

I'm trying to plan ahead for if the transmission has to come off before the end of the waranty (only two year in Spain).

If it does I'm thinking of a decent clutch and torque biasing differential (Peloquin) as I hate what traction control system must be doing to an open differential!

After that a Hybrid Turbo me thinks.

It's a bit in reverse to the way most people do things but why not?

James

I am still using my OEM DMF with no problems at all but i have heard of DMF`s failing on highly tuned diesels due to the extra torque ripping the rubber inserts in the DMF apart when driven hard. If you go SMF you can also get the flywheel lightened so the engine can rev more freely but there are down sides like the rattle in neutral as well which can make a diesel sound very ruff. Good luck with your car anyway and i hope it all goes well.