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popeye330d

330d turbo change

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Hey all.

I have posted about a problem on my 2000 plate 330d before.

It kills power at just before 3k rpm, then the power comes back and it will rev all the way to the red line.

Its had both pressure converters, map sensor, maf sensor, crank sensor all replaced.

When watching live data you can see why.

The air pressure gets up to 1.5 times what the specified values are.

Through alot of messing around ive found that the only thing it can now be is the turbo itself.

I have a turbo and oil lines, oil, oil filter, air filter and the oil line gaskets sat here now and im planning on changing the turbo over the weekend.

Has anyone done one of these before and could you give me any advice please? What kind of tools i will need? Any particularly hard parts of the swap?

I know i need to let the engine turn over for a few seconds without it starting, whats the easiest way to do this?

Thanks.

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to crank with no start, pull the fuel pump relay or the fuse. The best way to stop a common rail TDI starting is to disconnect the power to the fuel pump, preventing the rail from pressurising.

The turbo to manifold bolts will be hard to shift, they are on every TDI but a good skoosh of penetrant should work. New locknuts will be needed.

If you have overboost issues, check the turbo actuator (VNT) it may be stuck in the high boost setting from pootling around town on low throttle and not getting high enough EGT's. Google "Evilscotsman Mr Muscle VNT" for my original article on freeing a VNT's vanes for under a fiver. (VAG but hey it works and saved many people thousands of quids) - on audi-sport.net

;)

Edited by Scotty65
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Cheers bud.

Thats partly how i diagnose sticking vnt vanes. I did do the mr muscle trick and it worked perfectly for about a month then got bad again. It could never shift enough crap so i guess its well beyond the treatment. I do alot of motorway mileage so it gets a good visit to the red paint daily aswell as proper cooldown time.

So if i yank out the dde relay it wont start at all? Good to know.

Il grab some locknuts tomorrow before i start :)

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Yep no fuel pressure, no start.

I'm Evilscotsman - that was an epic thread! Folk took a bit of convincing but eventually the weight of success proved it beyond doubt lol. Remember your VNT actuator diaphragm rod may also be sticking, the VNT ring is not the only culprit but was most likely.

Also a duff N75 control solenoid can do this, as the VNT sits in full boost mode at idle after starting, and can jam there for a few reasons. Passing vac on the solenoid, jammed actuator rod / drum and jammed vane ring.

Edited by Scotty65
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Ive done the treatment a few times leaving it for longer, repeated soaking ect. Eventually it goes back to how it was. It has had a new actuator but no sucess so only option left is the vanes. The new turbo arm moves so much easier than mine and i can actually hear the vanes move. I cant on the turbo currently on my car so would you agree that it was fairly conclusive?

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Yeah mate, you may have excessive wear or distortion in the control ring / pivot pins or some such, and since you have a new one and repeated applications of the Sodium Hydroxide has less effect then you would be as well to swap it out now.

At least when you do, you can split the old one down and understand what went wrong. Not many units have resisted the treatment, my own audi tdi did 8000 miles after one treatment and never failed again in the time I had it but I got rid for a newer car so no idea how long the fix lasted. I would say leaving it in too long results in it kind of setting into a goo - 2 hours being the maximum time for a soak from experimentation, for others trying it the best time is about 1 to 1.5 hours then button up and give it a good blast on the main roads to blow out the dissolved carbon.

I'm sure the new turbo will give your motor a new lease of life.

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Well im currently well past the point of no return.

The old turbo is out. The new turbo is ready to mate to the manifold :)

Oil changed already got plenty left too.

The old turbo is goosed. Its got loads of movement on the compressor wheel and i have to force the actuator arm to move. After a few pumps it moves freely bit seizes again.

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yeah no lugging it in high gear low rpm, change up at 3k+ often, get the egt's hot enough to burn clean mate. give it a strong pull every now and then should keep you right, along with proper warm up and cool down time, 5 mins warm up 1 min cool down while running after driving. (dont just pull up and switch off)

If you do lots of short trips you will have to take it on the m way once a week and give it a romp.

;)

Edited by Scotty65
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ah even chemistry cant beat wear.

prob from mixing synth with non synth.

classic problem with audis - google sludge issue

Talk about jumping to conclusions. Components can simply wear out through no fault of the owner no matter how well you maintain it.

The issue with the VNT is probably down to wear also - it's a bit hard to explain but due to the way it works it's only actuated at a single point in the ring so once the metal starts to wear slightly the tolerances change and it can jam against the side of the compressor housing. Now you've got the turbo off you should take it apart and have a nosey......it's actually very simple mechanism.

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New turbo is on and working :)

I need to have a look at the vacuum hoses as its a little flat low down but it flies up top now. No power cut at 3k :D

Edit: nuts. Not that simple. Ive got vacuum as the actuator arm moves on startup. But when i rev high and change up it goes flat.

Edited by popeye330d
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ah even chemistry cant beat wear.

prob from mixing synth with non synth.

classic problem with audis - google sludge issue

Talk about jumping to conclusions. Components can simply wear out through no fault of the owner no matter how well you maintain it.

The issue with the VNT is probably down to wear also - it's a bit hard to explain but due to the way it works it's only actuated at a single point in the ring so once the metal starts to wear slightly the tolerances change and it can jam against the side of the compressor housing. Now you've got the turbo off you should take it apart and have a nosey......it's actually very simple mechanism.

I was referring to the play in the shaft bush mate, re loads of movement in the compressor wheel. If the bush was always lubed it would last a very long time I guess. Forced lubrication should prevent contact wear in sintered bushes and I've seen them last for tens and tens of years in machinery when the lube was clean and good, obviously could be down to poor maintenance of course as you say by not changing oil often enough, but if its got full service history it could have had multiple oil types used by indies etc and this can cause sludging and poor lubrication on a huge range of cars from vauxhalls to audis.

Not so much jumping to conclusions as observation based on personal experience. My audi turbo suffered this, and the oil when drained set overnight to a kind of jelly in the tub we collected it in. Previous garage had used semi synth and one after used fully synth. Audi have since issued a bulletin saying if this happens, the engine warranty is null and void. The problem is the heat of the turbo cooks the oil combo producing long-chain molecules that bind into a thick sludge when cooled.

Just my own tuppence worth, nothing more.

Edited by Scotty65
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Hey Popeye and Scotty,

I'm just about to do this on my 2000 330d... I'm going to take the turbo up to a place in Milton Keynes to exchange it for a reconditioned one for around £300.

Then I've got to source the extras, such as gaskets and oil lines.

If I replace the turbo assembly including the vacuum actuator, rod and all, the actuator comes preset to that turbo assembly? i.e. the unit doesn't need to be set up to my car specifically?

Did you get your low end flat spot sorted in the end Popeye?

Ta for any advice,

Chris.

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my turbo was goosed. the vanes were sticking and there was loads of play in the shaft.

it sounded like a police siren so needed doing anyway.

my flat spots are still there but sooo much easier to drive around. My cars ecu was reset so just needs coding and it will be perfect by the looks of it.

youl need the gasket where it mates to the exhaust manifold, i replaced both oil lines, oil, oil filter, the air box is open anyway so may as well change the air filter too.

crankcase breather (vortex type) aswell.

my turbo actuator was pre set by the place i got it from on their rig.

are you doing the job yourself?

I've only done the job once but i'd be more than happy to help if you need any advice

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Yup, doing the job myself.

I've had the top end off the motor already as there was a questionable 'reconditioned' long motor put into it, so I wanted to check the compression, condition of pistons, head and turbo.

All seem okay, apart from the rather sizeable amounts of play in the turbo shaft bearing... This is probably why it kicks out a significant amount of smoke under power!

Any pictures or tips are all appreciated! :)

I'm hoping that this sorts it and it goes on for a few more years! If not a 530d touring is looking a little tempting right now.

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