rgfmurray

Hi - I'm having a few problems with my 2001 Octavia TDI 110, there's some great info on this website and I now have a few ideas as to the problem, but I would welcome some extra advice please.

The turbo is shutting down. This typically occurs under load when accelerating from low revs in 3rd or 4th gear onto an uphill motorway slip road, the engine pulls hard until between 2700-3000'ish rpm I loose power. The fault is cleared by cycling the ignition. This has been ongoing for a while.

Recently, when first driving off, when I accelerate and generally in second gear I experience something similar to a misfire, at the same time there is a sort of "swish swish" noise similar to an actuator working / air rush? I have also had this swish swish noise occur repeatedly when holding the car at about 1700rpm in 3rd.This doesn't seem to happen when engine is warmed up.

I've had a diagnostic at the local skoda dealer and they have said I need a new turbo (£850 fitted inc VAT !!!!!)

I've read about faulty boost pressure sensor or sticking turbo variable vains causing this, but I'm reluctant to change the turbo straight away - could it be anything else?

Would the swish swish noise be coming from the butterfly valve located on the end of the air inlet manifold casting and which is operated by a small vacum bellows unit - Assume this controls excess inlet pressure?

If the vains are sticking would removing the turbo and flushing through with carb cleaner work? Better still, would spraying "Power Boost" or adding a fuel additive be worth a try first?

I've also seen an N75 referred to, can anybody explain what this is please?

Looking forward to your help and thanks in anticipation

Russ Murray

Lummox

Sounds like the vanes are sticking.

Ive never understood how carb cleaner or anything sprayed into the intake would help as by the time it got to the exhaust turbine and housing it will have been burnt up in the combustion process.

And if you want to clean the mech itself it means stripping the turbo down.

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rgfmurray

Thanks Lummox.
I've just been reading up on the Garrett website http://www.honeywell.com/sites/ts/tt...s_VNTworks.htm
I didn't realise the vains are on the turbine side but it makes sense, so as you say, anything like power boost will have been burnt up by the time it reaches the turbine.

With the carb cleaner, I was thinking about removing the turbo and washing it through with this. However, having seen a strip down on the following link http://www.technologie-entwicklung.d...t15-turbo.html I may well take it apart to clean it if I can do this without damaging any gaskets that joint the chambers which enclose the turbine.

I was just wishfully hoping that it might be something else.

Do you think the sticking vains may be causing the "swish swish" sympton which I think is the relief butterfly on the inlet. Possibly an overboost relief, but not enough for the management system to shut down the turbo, but just control excess pressure?

Thanks for the quick response - Russ

Lummox

Now you can see why these things stick up..



Should look like this..



And moves like so...



There isnt a relief butterfly on the inlet, boost levels are controlled via a feedback to the engine ecu from the MAP sensor to the N75 which actuates the vanes on a duty cycle.

The issue is these vanes usually get stuck at max boost, so you get lag, a large amount of whoosing then a kick. If the kick gets big enough the ecu registers an overboost fault. I changed on the other week at 16,000 miles where the car had been pootled around in. Didnt register any boost on test as the vanes were jammed solid all the way open, the actuator wouldnt move at all.

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rgfmurray

I'm not getting any lag, engine is responsive. Just get the turbo cut out after long period of boost such as accelerating up to motorway speed.

The wooshing is more of a short duration swish - usually speeds below 30. Also noticed on an occasion when taking foot off throttle to change up.

Also experienced problem yesterday when accelerating off a roundabout, It missed/swished then got really really lumpy - similar to a petrol engine with the choke left on - I managed to drive through this - Any ideas please?

Plan to try to disconnect linkage between vain actuating arm & bellows so I can feel any sticking when I operate it - suspect I will. Next step will be out with the turbo & strip down.

Could you tell me what the butterfly valve does please? I noticed that it actuates when you switch the engine off also?

Thanks again - Russ

NascarMike

My mate has turbo diesel Fabia 105 bhp model and whilst in Germany last year, he could not get more than 3000 rpm from it and we were travelling back from Belgium.

We thought that the turbo had gone as well.

When we took it to the dealership in Frankfurt, the dealer diagnosed that one of the hoses had been chewed by a martin (a small mammel like a squirrel) and the ecu had gone into a "safe mode".

The replacement hose and diagnostic only cost 35 euros.

Maybe try another dealership for a separate diagnostic check and hopefully it isn't anything termibal.

Best of luck.

Lummox

Russ,

The flap is mainly for EGR. As a diesel doesnt have any inlet manifold vacuum then exhaust gases fed into the inlet wouldnt be drawn into the engine to be reburnt. The flap partially closes causing a depression behind it so EGR will work. It is also shut off when you turn the engine off to stop diesel run on.

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rgfmurray

Thanks Lummox

I got the car up on ramps today to see if I could disconnect the vain actuation linkage and feel any sticking - you'd need to be a contortionist to undo the circlip, I gave up.

It looks pretty tight to get the turbo out - do you lower it out? the driveshaft appears to be in the way, also looks pretty tight to lift it out.

Also I couldn't see clearly, but I couldn't see or feel any flange or joint between the exhaust manifold and exhaust inlet to the turbo - is it all one casting?

The more I look at it, I might just bight the bullet & get the local Skoda dealer to sort it out, although the thought of paying out £850 brings a tear to my eye.

Thanks for your help in answering my many questions.

Cheers

Russ

DJM

I have a thread with a very similar problem (see 1.9Tdi running out of oomph) - I don't think it is the Turbo... Hmm same year motor - mines a 51 plate...

boginhood

hi ya mate had a simlar problem myself,cars out of warranty and dealer suggested fuel additive,put diesel magic in tank and 10k in air side but spray other side of airflow meter, after a couple of minutes somthing ressembling fog came out of the exhaust took for a ride round and more responsive but still shutting down so restarted engine and built power up gradually over next few days didnt go to point of shuttdown to start with then gradually build up revs on accelleration a bit at a time after couple days clear,also found the odd 100-110 mph blast for a few minutes makes it perform better as it blows all the crap out hope it helps,i couldnt understand how the additives would work either but when you put the 10k in youll think the engine has blown with all the smoke, but it does what it says on the tin and i use it every time i service the car.my problem started at about 63k when i used additive its now done 107k.

mbames

Sounds just like the problems I had about months ago. I replaced the MAF and v75 valves first (as Westover told me they were faulty), but to no avail. It was decided that something was sticking in the turbo, and that a new one was needed. Fortuantely I sourced one FoC, and had my mechanic fit it (3hours @£25/hr)

johnyardley

Hi, If you ring allards 01452 500333 speak to Lloyd I bet he has a replacement for a fair price if you need one.

Best wishes

John

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cmcm789

Excuse my ignorance, but what is 10K??

My TDI has 37k on clock doing mostly stop start driving, and i would like to give the engine a bit of a flush out sometime.

JD

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cheezemonkhai

10k is a solvent of some description, i can't remember if it's a boost or adative, but it claims to clean crap out of things.

As ross said though, that part of charger is on the exhaust side, so i have no idea how it would work as it's been burninated before getting there.

greg123

Don't forget that the MAF failing gives symptoms like this. If the turbo is spooling fine it's difficult to see that it could be shot, though if the vanes are not moving it could be running out of puff. I'd get it fault logged and check/test a new MAF after clearing faults and see if that fixes it.

Lummox

Usually with a MAF fault though it doesnt clear by cycling the ignition.

The lack of power isnt caused by a shot turbo. Its producing boost, thats not the problem. The issue is its producing to much at the wrong time so the ECU shuts it down.

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oskah

I have hear of a case on a 130pdtdi Golf where the vanes on the vnt were sticking so when it reached max boost it took to long for the vanes to back the preassure off the turbo causing it to overboost and go into limp mode. My GF had the same trouble on her 110tdi Ibiza where you pull out to overtake boot the throttle it pulls away fine then suddenly loses all power. It was a bit hairy to say the least. switched the engine off for a bit and it was fine again. Seat dealer said it was the maf. I showed them the magazine with the 130 golf with the same problem but they were not interested and changed the maf. needless to say that didnt work and in the end they changed the turbo and it was fine.
hope this helps

cheezemonkhai

How difficult is it to take the turbo out?

I assume exhaust goes through the center where you can see vanes, but are the oul pipes the two bits at either end. Just curious as to how much work it would be as I'm willing to spend a day taking it off cleaning it up and putting it back to save £1000.

I mean are there any seals that you could have to replace etc, or is it just a case of off, seperate, solvent & toothbrush clean, put back together, fit it back in, top up oil and then go again?

Lummox

Not quite the same but similar.

http://www.technologie-entwicklung.d...t15-turbo.html

Turbo is a piece of cake to take off, but then i would say that as ive done loads of them. Its all relative to your skills.

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cheezemonkhai

I'm amazed that there are not local turbo specialists or similar that will recon your existing turbo for a small fee. Seems crazy to pay £1k when they could just take yours off, put a recon on and send your off for a recon.

yaktrebor

What's the best way of keeping the turbo in good working order?

I guess, as I spend half my life on the motorway, this is OK?

Although, at 70 mph, the rev's are quite low on my TDI.

Do I need to give it some stick every now and again?

My turbo was replace due to this problem at 56k. Dealer paid the £1k.

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cheezemonkhai

I would guess a work out of the turbo so you blow all the crap out of the back can't help and it would make the vanes move fully

Oh Ross, I've seen that page, just wondering how to remove it from the engine as opposed to disassembly really. Any help you got would be great

rgfmurray

Thanks for all the posts - the symptons have been getting worse so I finally decided to strip it down.

Getting the turbo off wasn't to bad, had to remove the inlet manifold to get clearance. The clips on the rubber pipes were the biggest pain. I was surprised that the exhaust manifold was part of the turbo casting - expected a flanged joint to the manifold.

Once off, I disconnected the bellows unit linkage that actuates the veins and it was immediately obvious that there was hardly any movement and extremely stiff. When I split apart the outer housing to access the mechanism that moves the veins, you could see that it was coked up with carbon deposits. Removed the actuating ring that sits on 3 rollers and scraped off the carbon deposits. Also generally cleaned up.



Once reassembled I had full movement on the veins with no sticking - things looking very promising.

Back together and out for a test run. Success and £850 better off. Performance has picked noticeably. One very happy Skoda owner.

I have learnt a lot from this forum, and now understand how the variable vein turbo works and how the sticking veins cause overboost - When I stripped it down the veins were partially nozzled in with not enough movement to open out, thus causing overboost as engine revs picked up and hence exhaust gas flow. The venturi effect of the veins causing overboost at kigher revs and thus shutdown

Thanks for all your support & contributions to this post.

Russell

Attached Images

	Actuating Ring.jpg (313.2 KB, 139 views)
	Turbine.jpg (328.4 KB, 139 views)

stranger

as to the swish noise we had the same noise that turned out to be a split in the intercooler air pipe ( rubber joining piece) behind o/s headlight

L&K TDI

Hi Russell,

I have been following this thread for a while as I have exactly the same problem. I have spent £200 so far on a MAF and N75 but still have the problem.

I presume it's a fairly easy job to remove the turbo but is it done from the top engine or from underneath? I'm pretty handy at this sort of thing but without a manual it's difficult to know where to start. Also did you have to replace any gaskets etc.

Any tips would be greatly appreciated.

Thanks

Michael