Mk2 Turbo Vane Problems!

[galaxy]

Hi,

I was wondering if anyone out there has some practical experiences with the turbo vane mechs fitted on a MK2 Galaxy.

I've had a good look through the threads on this website and used the information to get as far as proving whats working and whats not (by the way it's a great site).

Basically I've lost all boost - I've been under the car today and applied about 20" vacuum to the Vane diaphragm - but it didn't move at all, thus i've found my problem.

I tried giving the actuator arm a little help - but could only move it in one direction. I was expecting the rod to move towards the diaphragm unit (due to vacuum), however the only movement i can freely get out of the rod is away from the diaphragm? Is this right? - Should it pull towards or push away from the diaphragm.

If it is right and it pushes away, then the vane is actually working fine - it's the vacuum diaphragm unit not moving the rod.

Before I start stripping the thing out and getting it replaced/ repaired I'm interested in finding how the rod moves away from the diapragm unit under vacuum (unless the unit is constructed in a abnormal way).

 

Additional - can the vacuum unit be replaced?

 

Thanks

Dave.

[f0ster]

not too sure but there is a possibility that it uses boost pressure to operate the control rod, trace the pipe that feeds it, it should go to a three way solenoid,

I think called the n75 valve, then follow the pipes from there

[Scorpiorefugee]

I have chased this around on my AFN engine and the following may be helpful.

The vacuum is produced by a vacuum pump on the front (radiator side) of the engine and this is also the source of the vacuum for the brake servo. The feed is teed off to the variable vane and recirculation control systems and it is possible to pull off a tube and check for vacuum. The control system uses 2 three way solenoid operated valves and a reservoir tank behind the radiator header tank. The solenoid valves are operated in pulse mode and are known to fail occasionally although, when I took mine out I could not make any sense of how they actually work. I suspect that mine are faulty but I still get good turbo action. It helps if you have a TIS disc and can trace all of the tubing but, even then, it is not easy to follow a logical fault finding path beyond checking for leaks and vacuum while the engine is ticking over.

 

Good luck.

[f0ster]

on the n75 valve there are three ports, when the valve is "not" energised two of the ports are connected, if you then energise the valve the main port then switches over to other that was not previously functioning, if you intend to test the valve you need to make sure that you energise it with the correct polarity,

with solenoids there is usually a protection diode built in to the coil to get rid of back emf and connecting it backwards blows it up,

turbo removal might be required, there is a website showing the internals,

[Scorpiorefugee]

F0ster,

 

Thanks for that. I don't think mine had the diode. In my experience (not auto) the diode is usually panel mounted to protect the switching semiconductors. I had assumed that the valve arrangement was pretty much as you described because that is what made sense from the requirements. However, both the boost control and recirculation control seemd to allow passage reasonably freely from all 3 with minor effect from the energising coil. (Not entirely surprising after nearly a 1/4 million miles of careful neglect.) Not having replacements, I wiped everything over and put it all back and, after a lot of nervous research, found my problem to be one or more injectors which recovered completely after an accidental tankful contaminated with 5% unleaded. :rolleyes:

 

It now runs as well as ever. My point is that these things seem to be quite fault tolerant up to a point.

 

It's a funny old world, innit.

[galaxy]

Thanks for the input so far guy's.....

For those how are interested...

 

The pipes connecting to the n75 valve are easy to trace (well on my Galaxy they are), one goes to the Air intake down pipe (going to the turbo) - and is connected just after the Air Mass flow sensor, this is the Vacuum line. I checked this and I was getting some limited vacuum out of it - however until the turbo goes onto full boost you won't get full vac.

The other pipe goes to the turbo - the text book quotes this connection as atmospheric pressure - however in theory, as long as it starts to release the n75 valve which it will as soon as the n75 valve swaps over then boost is released.

 

This valve is operational as far as I can tell, I have already proven that the vacuum diaphram isn't moving the rod - however I struggling to understand how it moves the rod out rather than sucking it in? It almost suggests that the pipes were connected round the wrong way. However the TIS clearly states it is operated under Vacuum - and then shows how to test it!!! So it's got to be right.

 

I noticed a few pictures of a Turbo that been pulled out of a Galaxy MK2 on this web site - however this picture and others I seen elsewhere all show a slight variation on the equipment. The vacuum diaphram units all point downwards and are pretty much central - however my unit has the vacuum diaphram mounted on the right hand side (pointing off side - looking up from under the car) and activates a rod across towards the near side? I can't find any pictures with this description?

Have any of you guy's out there got a simlar type Turbo configuration or have I obtained a special?

[Scorpiorefugee]

Galaxy,

 

As far as I have been able to work out, it is as I wrote, the vacuum which makes everything work is the same as for the brake servo. If you have brakes, you have vacuum. The pipe to the air intake is used as a supply of clean air and is only used to turn things down(I think). Cirtainly, on mine, there is not much happening there and any vacuum in that pipe is due to the control system using it to turn down the system. (or up - I didn't need to work that out.)

 

If it's any consolation, yours does sound similar to mine. I believe the GLX classification indicates 110bhp and, if you can find it, AFN on the label on the top of the cam belt cover. (I couldn't find mine!)

 

As far as sorting out the plumbing, I wouldn't call it easy cos you have to take the bulhead panel out as if to get at the wiper mech and then it's not too bad. There is also a non return valve between the two solenoids.

 

Someone gave me a brilliant link to a full description and if you have a brouse through my topics in the past few months you should find it. It's well worth the look. Sorry, I'm whacked at the moment and I'm off at 5:00 tomorrow. If you're still struggling in a day or two I see if I can find it.

[Desmond]

I also lost all turbo on my galaxy and thought it was the turbo, i am not a mechanic so i asked my neighbor mechanic to have a look and he found a split in a large pipe going into one of the radiator doohickeys ant the lower front of the vehicle,it is now ok and has been for 12 months

[davgree]

Thanks for the input so far guy's.....

For those how are interested...

 

 

I noticed a few pictures of a Turbo that been pulled out of a Galaxy MK2 on this web site - however this picture and others I seen elsewhere all show a slight variation on the equipment. The vacuum diaphram units all point downwards and are pretty much central - however my unit has the vacuum diaphram mounted on the right hand side (pointing off side - looking up from under the car) and activates a rod across towards the near side? I can't find any pictures with this description?

Have any of you guy's out there got a simlar type Turbo configuration or have I obtained a special?

 

Hi, I replaced turbo on my 2004 Tdi 115 Auto ( AUY ) about 3 or 4 weeks ago, so this might help you

[Scorpiorefugee]

Not sure, but I was reading an article on the VeeDub diesel prior to the PD family, use a 'needle lift' sensor in one of the injectors to accurately set and control the timing. If the sensor fails it falls back onto basic timing.

 

 

Have a look at this

This is the bit that helps it all make sense. Hope it works

[galaxy]

"Hi, I replaced turbo on my 2004 Tdi 115 Auto ( AUY ) about 3 or 4 weeks ago, so this might help you

[galaxy]

Right Guy's,

I have an update, I went under the car again and this time applied some positive pressure.... Hey presto! The vane actuator arm moved away from the unit!!!

This is proof that my unit moves the vane actuator on postive pressure???? Completely the reverse as to what the TIS guide gives? Does this mean someone has fitted the wrong turbo at some stage?

 

It also raises the question now as to how the n75 valve can work properly! I had this off as well and started blowing into various holes: I seemed to get different results each time I switched the ignition on and off. I'll do a bit more digging on this one as I beleive this valve is variable, rather than just two position - I think it can actually have all three ports open at some stages: Has anyone actually proof tested a working unit to see what it should do and on what pipe?

 

I've attached some shots of the turbo and the n75 valve for reference should anyone need it.

 

1: This is what my vane actuator looks like:

2: The turbo:

3: The n75 valve:

 

I did have a play with the pipes on the n75 (swapped some around) and managed to get a very small amount of movement on the turbo vane actuator - I'm going to have a think about it and test the n75 properly first. Watch this space.

[Scorpiorefugee]

As I said in my earlier reply, my valve exhibited much the same sort of behaviour as yours but, as my problem was intermittent, I was reasonably confident that the problem was elsewhere. The valve is operated pulse mode by a fast switching pulse so there is obviously something going on that is not explained anywhere that I have looked.

 

Have you checked for vacuum on the pipes around the valve? I could detect a useful control vacuum in the feed to the vane control

 

Have you checked the error codes yet? This, together with some running readings from a VAG com would help enormously because that could indicate the readings that the control system is getting and what it is trying to do to make things work as they should.

 

There is a valve in the system, in my case between the boost control valve and the recirculation control valve, and mine was totally shot. I replaced it with a valve from a fish tank air line but it made no difference at the time but as mine works fine now I cannot really comment on its importance in the system.

Edited December 21, 2008 by Scorpiorefugee

[seatkid]

Deleted......gone to check my info..... Edited December 21, 2008 by seatkid

[galaxy]

I do need to get the error codes checked out again.

After some investigation I have descovered that something isn't quite right with my motor. The car was orginally advertised as a 115bhp TDI, however the engine code is clearly ANU. This means its a 90bhp version - fraud have also verified this?

Stranger still, the turbo is actually a 90bhp version which is why it looks different to the other pictures on this website, however the control gear seems to be 115bhp variable vane type?

I was under the impression that the 90bhp version uses waste gate technology and utilises a different type of actuation unit. If you look at my photos above you can see the turbo solenoid valve which according to the TIS is 115bhp variable vane control gear? It might be that my car should have a 115bhp turbo fitted to go with the control gear... or someone has been bodging

 

Has anyone got a 90bhp version who has this type of control gear?

 

In answer to you question, I did check all of the associated pipework and found the following:

1: One pipe from the solenoid goes to the turbo air intake and creates the vacuum pressure

2: One pipe goes to the turbo, which when tested gave a positve pressure

3: The last pipe goes to the vacuum actuation unit on the turbo: i.e. adjusts the boost.

 

I took the solenoid valve off and tested it on the bench and it works fine. As before, the trouble is the vacuum actuation unit on the turbo doesn't move under vacuum, it only moves under positve pressure? However, the turbo solenoid only supplies vacuum for boost control, the positive pressure is used to reset the uint and release the boost. My only assumption is that the turbo actuation unit is shot.... I'm going to have a talk to some turbo specialists and find out what type of pressure actuates my type of turbo. I can then start to work out whats going on.

[big_kev]

After some investigation I have descovered that something isn't quite right with my motor. The car was orginally advertised as a 115bhp TDI, however the engine code is clearly ANU. This means its a 90bhp version - fraud have also verified this?

 

Are you positive its an ANU engine, I thought you had an Automatic ?

[seatkid]

AFAIK all vw engine turbos are controlled by a vacuum operated actuator. It sounds as if yours is stuck in the boost position. This from what I read is usually because of failure internally of the vane mechanism. If I were you I'd take the turbo off, examine and start a strip down.

 

Alternatively spray liberal amounts of WD40 to the actuator rod (turbo end) and after a soak-in period use pipe plieres or something similar to work the rod - see if it looses up.

 

There is a thread posted some time ago with photos showing how to do this, apparently the actuator rod can become encrusted with hard carbon, jamming its movement.

 

PD engines are all variable vane, the old Tdi 90bhp (AHU) was waste gate.

[galaxy]

Update:

Right, after getting hold of some test equipment I have the following results and advice for all...

 

The Engine is a 90bhp ANU type, however having read the VIN code the car appears to have come out of a German factory but registred in England? Don't know if that makes a difference.

The Turbo (look at my previous pics) is actually a wastegate type (not variable vane). I proved the actuator runs on positive pressure as well and is working fine.

The solenoid valve which is the normal you would find on a 115bhp Variable vane controlled type is indeed a 'standard fit' for this model and year (I fail to see how though), even though it is plumbed the same way, it actually uses the positive boost line from the turbo to control it. So if you read above how the variable vane runs.... this is the opposite.

The solenoid stops the pressure getting through to the actuator until it reaches full boost, then starts to back it off. But it uses the same gear.... not the standard wastegate control gear, so be careful if your model is a 2000 such as mine. It looks like Ford have mixed the components on the early models before they set the "standard".

 

I ran the car with a turbo gauge plumbed in... must have looked funny with these pipes hanging out of the window while I booted it up and down the road.... anyhow I digress:

The turbo boost gets to about 15PSI on full boost, the wastegate starts to operate at about 7-8 PSI (reading from the actuator), although the actuator will fully open the wastegate at about 15PSI.

Everything turbo wise is actually doing what it should be doing: i.e. A waste gate type has the turbo on boost all the time, the positive pressure moves the actuator away from the unit and opens the wastegate, thus releasing the pressure. If this doesn't move you will get an over pressure fault and the car will switch to limp mode.

My car was showing symtoms of lack of power and hunting at high revs.

I pinned my money on the TMAP ( as the wastegate runs on pressure - I assumed it may have a direct effect on it) after a bit of investigation, managed to get an after market (new) MAP for

Edited January 14, 2009 by galaxy

[galaxy]

Further update:

New MAF sensor replaced, which squeezed the top end power out of the car. It's now running great.

A good point to note is that I swapped the MAF at the start but it didn't make any difference..... that was because the TMAP sensor was shot and the system was ignoring both.

Another point is that I ran the car without the TMAP and it made a big difference to the running of the car - it was really slow. You would have assumed from that the TMAP was working fine then.... not the case.

After the TMAP was replaced and the car started to respond better I tried the MAF again and it made no real difference.

Now a new one is fitted I can see the difference... its not massive but it is definately better.

 

Job done! Hope it helps.