Anyone clued on the VW 1.9 tdi engines?

[stevepeanut]

I've bought a 1996 Audi A4 which has the 1.9 tdi engine. I've been told this is a VW engine, same as in golfs, seats, skodas and others.

Round the streets the car is spot on, but as soon as I get to a bit of motorway with an incline or need to do a motorway overtake, the turbo dies off and I loose power.

I've been looking into it and from what I can it could be a very common fault with the turbo vanes starting to stick. I've done what's been suggested on a lot of the sites, to put some Mr muscle oven cleaner into the turbo manifold as this is meant to clear off the carbon and put things right. Once the oven cleaner is in place, the actuator needs to be moved up and down every 10 minutes, to slowly free it off. On mine there was almost no free movement in the actuator rod, after a bit of pushing and pulling on it, I've now got about 5mm of movement. But on videos I've seen, it looks like it should move up and down 20mm or more.

Anyone got any thoughts on this?

Also if anyone can point me to a good Audi forum that might help too.

[vertex]

Worth a try

www.vagoc.co.uk/vb/

[Rich]

Needs the turbo removing and stripping to find the cause of the seizure. Could be the vnt vanes have fallen off and jammed the turbo or it could just be jammed with rust and carbon and need cleaning up.

[stevepeanut]

I'm wondering whether it would be better to buy a used turbo unit, there's lots on eBay for under £100. I don't imagine a turbo strip would be something I could do at home.

[Rich]

Sept 1, 2015 19:47:55 GMT stevepeanut said:

I'm wondering whether it would be better to buy a used turbo unit, there's lots on eBay for under £100. I don't imagine a turbo strip would be something I could do at home.

You can, you need nothing more than a few torx bits and a really good 10mm spanner. You aren't removing or disturbing the core or bearings other than removing the exhaust housing to get at the vnt. It's pretty simple. If you are technically minded enough to be able to remove it from the car you will be able to strip the hot side housing off

[contrarian]

This should have the 110 brake AFN engine. If so there's a short rubber boost pipe only a couple of inches long joining the hard plastic turbo pipe to the inlet manifold next to the EGR valve. This splits on the bottom where you can't see it and the resulting boost leak puts you in limp mode. Sorted this on my old passat and it chuffed loads of smoke for a day or so and got a fair bit quicker once it cleared itself. This more or less cured mine but it would still occasionally go into limp if I really caned it.

Worth a look and the pipe was pretty cheap from memory.

Hope this helps.

[duggers]

Mr Muscle is cheap effective method of cleaning the VNT but do not get it on any aluminium parts as they will disappear.Takes a very short time to do.
Have you done a logging session on Vagcom or similar as this will give you accurate Turbo data . If the actuator is stuck you have got serious carbon build up!
Always check vacuum hoses to the turbo and any associated valve.

As stated the 'proper' thing to do would be to take the turbo off and do a strip and inspect

Had the AFN in my old Sharan and never suffered limp mode or performance drop but then i did give it regular Italian tune ups.

[stevepeanut]

Yep this one does have the 110 engine.

I am struggling to get my head round it all to be honest, I've never done much with turbos apart from some tinkering with a Kawasaki 750 turbo bike I had years ago.

I will check all the hoses tomorrow.

Should the actuator rod go smoothly up and down with just the force of moving it with my hand? It seems solid to me.

Haven't done any plug in checks yet.

[g40jon]

How well has the car been serviced? A few years back I had a 9n polo with the 3 pot 1.4 tdi (its derrived from the 4 cylinder 1.9 tdi, just munis a cylinder). I had a problem very similar to what you describe, i.e. the power suddenly drops off, almost feels like the turbo has stopped boosting. Well after replacing few bits, the car was no better. So I decided to get back to basics and give the car a service. Changed the oil, oil filter and fuel filter and the car was transformed. I can only assume the very grubby fuel filter was starving the car of fuel at higher engine speeds.
Worth a try before spending big money or removing big parts from your engine!

[gavs1]

i remeber having a vw sharan that had a similar issue, turned out 2 be a split vacum hose in the ecu

[stonyray]

Mr Muscle foaming oven cleaner in the steel side of the turbo. Take the egr pipe off and squirt it in. Give it 5 mins then work the VNT actuator arm back and forth. Should get rid of the carbon build up stopping the VNT working.

Whats happening is (from the sounds of it) when you boot it the turbo spools up and the VNT vanes (controlled by the N75 valve) can't move back to lower the boost the car overboosts and the map sensor (built into the ecu on these early AFN (110bhp) diesels puts the motor into limp mode. Hence your lack of power. Had this on my old 1997 A4 after I modded the fuel pump and had over 20psi of boost at full chat.

[stevepeanut]

Jon, I'm not sure when the car has its last service, it has got a a lot of history in the first 75% of its life, but not as much in the last couple of years.

Ray, I did the Mr muscle thing last night, the thing that I am struggling with is that there seems to be almost no movement in the actuator arm. I have heard they stick and you have to sometimes really force it to get it moving, but I don't know whether mine is jammed up or down.

[bigfella2]

I might be wrong here, but isn't a 96' too early for a VNT turbo, and therefore not have the vaines that stick. Not sure when these were introduced, but I thought 2000 or later was when they started with these types of turbo.

[contrarian]

I think the AFN engine was the first to have VNT. These came out 96/97 around the time the B5 passat was introduced. The PD engines are the ones introduced around 2000.

[stevepeanut]

I've joined an Audi/VW forum for some help, this car does have the VNT. There's still a lot to look at, even a leaking hose would cause the problems I'm having. I just hope it's a simple fix as I've skinned myself to buy this car.

[stonyray]

Oh mine also split a boost pipe as it went into the inlet manifold on the underside. That had me puzzling for a while. With the Mr M I filled mine to the brim and left it for 10 mins. After that I could work it back anf forth with ease.

It is normally down so you want to be able to pull it up.

[stevepeanut]

I have learned a bit more from reading articles. The actuator rod itself apparently is very difficult to move by hand. So what I need to do is unbolt either the actuator and remove it, or undo the rod, so if do either I can move the arm on the turbo, this should move very easily just with my fingers.

Just got an early finish from work and I was going to have another look, but its just started raining and I can only work outdoors, it'll have to wait for another day.

[Thrasher]

Next thing I would do is get some fault codes off it mate before you start taking things apart. :-)

You can get ones that work "ok" off ebay.....should be fine for what you need to find out.

If you get really stuck, get down to Darkside Developments in Barnsley ( TDi experts and racers ) - they'll be able to check the codes for you.

When its sorted , replace the egr with a straight through upgrade pipe - stops it all clogging up with soot....welcome to TDi world.

[stevepeanut]

After the rain stopped today I took a drive to my local garage, they are the perfect garage, friendly and helpful. The kind of place that let me use their lift or pit and tools if they are too busy themselves to look. I know they had recently bought a high end code reader. I asked if they could try it on my car for me and next thing it's put it my hand and I'm told to help myself

I plugged it in and no faults were showing, fired it up and no faults were showing. I asked if I could borrow the reader while I took the car onto the motorway to high speeds to get the fault to happen and hopefully show the code. For the first time since buying it, the car went straight up to motorway speeds with out any power loss. I held the car at 65 and waited for an incline and floored it, the car took off and pulled right up to decent speed with no turbo power loss.

Yesterday for the second time I had used some Mr muscle on the turbo inlet, although this time I had a much better idea of what I was doing and how to move the actuator rod. I am really hoping what I have done has freed off the vanes and made the car work like it should. All is looking good, and if the problem has been sticky vanes I need to look into it more and prevent it from happening again.

[stevepeanut]

Thanks for the tips thrasher, Barnsley is nice and close. I don't fully understand what an egr does but all I see time and time again is to get rid of them.