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Discussion Starter #1
Right!

I posted a while ago concerning the combination of strange noises our '96 2.4D has started to make. It has a 2.5 TDi manifold and turbo fitted (though not by a VW specialist, which may be relevant to the subsequent problems!

No one responded, so I've ploughed on alone!

So - thus far, I have (with no real technical knowledge or mechanical background) removed the EGR system (blanked at both ends) I've removed the inlet manifold, exhaust manifold, EGR assembly and turbo. That was a joy, as I'm sure you can imagine!

I replaced the inlet and exhaust manifold gaskets then found that the gasket between the turbo and the flange on the manifold was a paper one, so have replaced it with the correct metal one. So... no more Harley Davidson impressions from there.

I had also had a variable pitch squeal that appeared after the first refit of the inlet manifold. As people were starting to look as we went past (not just because of the colour of our wheels!) I repeated the manifold removal process, only doing the exhaust manifold as well.

Pleased as punch, I fired her up again, convinced I'd cracked the noise problem by making sure the lever on the actuator (the flappy bit in the turbo body housing) didn't pass the upright position. In a static test, all seemed good - exhaust blow cured, no screaming noise.

So, showered and clean and ready to celebrate, out we went. After 100m, the squealing noise started again.

AAAAAAAAARGH!

Anyone any ideas what it might be, please?

Seriously, please - I'm losing the will to live here.
 

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Could it be a bearing, say in the alternator or power steering pump?

My van has been making a whining noise for months and my garage says it is the power steering pump. I have it booked in next week to fix it.
 

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Discussion Starter #3
Hi there,

Thanks for your reply - I was beginning to wonder if anyone was ever going to respond!

I'm pretty sure it's turbo related - no noise at low revs, but a speed dependent racket when I put my foot down.

The PS pump has only been on for around 4 months, which removed another of the horrid noises!

I don't think it's the alternator, either, as I would have expected to hear something from it even without load on the engine.

I will double check as far as I can, as you could be right.

Thanks for replying!
 

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Take off the aux belt and go for a drive, you'll have no power steering or alternator so obviously be careful! It'll rule out those odds and ends that could be giving you bearing noise
 

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Discussion Starter #6
Hi! I don't appear to have any turbo boost control (or any idea how to install any!) the turbo was fitted by a competent mechanic who has serviced previous vehicles of ours, but I'm not sure he has the specific knowledge required for doing this particular mod.

If you can point me in the direction of what I might need to fit, that would be great. I'm quite good at following simple mechanical instructions, just don't get too techy on me - I'm a simple souls at heart!

Thanks so much for replying - I was getting lonely trying to resolve this issue alone!
 

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hmm, see as I understand it, and somebody out there might correct me, the boost / wastegate on a 2.5tdi is controlled by the N75. Which works with the MAF and ECU to deliver the correct amount of fuel / boost pressure at any particular load. Now maybe your van is set up mechanically where the standard injector pump has been set to match the turbo and it has some mechanical wastegate, but I fail to see how you could put a 2.5tdi turbo on a 2.4 straight diesel without all the controls to go with it???
 

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Discussion Starter #8
You're almost certainly correct. The problem was believing in the mechanic (who has been great at other jobs over many years) I'm a bit out of my comfort zone with the whole turbo system, so trusted him when he said all would be well. It did seem a bit quicker, but that could have been down to many different things!

I'll try to bone up on the more technical side of the conversion via the various threads on here.

Thanks for your support!
 

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Discussion Starter #10 (Edited)
Hi! As requested, here are some pics. I hope they help to explain what's been done.

I get what you say about our mechanic - he's great at servicing, repairing and maintaining but I'm not sure if mechanical conversions are his forte!
 

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All is not lost. There are quite a few 2.4s running Exhaust driven Wind pumps on here so im sure someone will be along shortly.

Getting a reply is a bit like being the first person up to dance or going to the Buffet at a party. It only takes one. :D
 

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Hmmm, I'm guessing it's squealing because the turbo is overboosting and blowing gaskets or something. I'm afraid you just can't throw a turbo on with no control and hope for the best.
The dangerous thing is if he has put on a turbo without modifying the fuelling the van will be far too lean and you risk doing damage to the engine internals.
You really need to find out exactly what he did
 

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Discussion Starter #15
Aaargh!

I think he did exactly that - threw in a turbo!

Is there anyone reasonably close to us in SE London who could take a look at the installation as it stands and help make it work properly?

Thanks everyone who has responded to my cry for help!
 

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You can't just add more air, you need more fuel as well to maintain the stoicometric ratio ~ fuelling needs increasing otherwise power is lost, not gained.

The 2.5tdi turbocharger you are using does not have a preset wastegate turnover pressure, it needs external control hence the N75 valve.

For starters I suggest you remove the entirely unusable and disconnected anti shudder & EGR valve assembly, this is easily effected by replacing with an Allard pipe such as this:

http://www.allardaluminiumproducts.co.uk/egr-valve-delete-pipe-vw-t4-van-transporter-2-5-tdi-new.html
 

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Discussion Starter #17
Aha! Thanks for that. Does this pipe not do the same job as simply blocking off the EGR pipe? If so, that part of the project has already been taken care of.

I'm sorry to be such a numpty on this - but the daftest question is often the one you don't ask!

Thanks for your patience and help.

Stuart
 

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Aha! Thanks for that. Does this pipe not do the same job as simply blocking off the EGR pipe? If so, that part of the project has already been taken care of.

I'm sorry to be such a numpty on this - but the daftest question is often the one you don't ask!

Thanks for your patience and help.

Stuart
Stuart, you need to lose the anti shudder valve ~ the pressure of the inlet tract is sufficient to make it close & starve the engine of air (can cause a shriek noise....)

Your turbo has a positive pressure wastegate, therefore in it's current configuration it is not offering boost ~ you may get around this by using a wastegate bleed screw; you'll still have to increase fuelling on the pump to achieve a worthwhile power increase.
 

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Hi - and thanks again for your help.

Would this do the same thing? If so, it has the advantage of a pre made port for the turbo controller.
http://www.egrvalve.co.uk/index.php?page=T4-Van-Transporter-2-5-Tdi-EGR-Kit
It is exactly the same thing as I suggested earlier (it's an Allard pipe) ~ the port is so that you can fit a boost gauge, nothing to do with controlling the wastegate.

You need this:

http://www.ebay.co.uk/itm/TURBO-MANUAL-BOOST-CONTROLLER-NOT-A-BLEED-VALVE-/220537042109?hash=item33590834bd

You connect it into the existing rubber wastegate pipe.

And a dash mounted boost gauge for setting up is very useful.
 
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