Jump to content

passat pd100 fixing


tobyd
 Share

Recommended Posts

Some of you may have noticed i put my passat tdi up for sale the other day. Whilst i'm hurt no one immediately bought it I'm slightly relieved as it became an sdi model the other day. 1500kg of car, 1.9 diesel with no turbo does not equal anyones rapid escape from Ipswich.

Plugged in the computer which said it was sad that the turbo was overboosting and won't be available. This can be fixed with turning the car on and off again but will come back as either: the turbo is full of crap and can't adjust or the controller valve is bollarded. Now, the car has done 213k so i'm not expecting its factory fresh mpg but it is on the low side so rather than dick around with pouring mr muscle down the EGR hole and hoping it works and doesn't roast the seals i opted for just ripping the fucking thing to bits.

first off is remove the airbox arrangement. this is about 5 screws and a bolt.

intake.jpg#

This went without drama. Slightly below center you can see the turbo sulking.

turbo start.jpg

With all that crap out the way you can see some pretty rusty nuts and bolts. My main fear was the three 12mm nuts holding the turbo to the rest of the exhaust. I figured these would be crisp and prior experiance of VWs makes me nervious about there hopelessly terrible fixings. Significant quantities of wilkos penetrating spray were deployed.

exite.jpg

3 for 3, even using a 12-sided spanner for one of them like a total pro.

oil.jpg

this is the oil feed, they are reputed to be a bit of a dick and shear off instead of undoing. it was tight but came adrift. its a bit rank so i might replace this.

no intake.jpg#

at this point i removed the intake. This came off without a struggle. the ports are a bit skanked up and the intake needs some nitromors or something tipped through out. The engine is pretty greasy and rank but this seems to have been kind to the fixings to far.

gubbins.jpg

all this rotten hosery and wiring is the n75 machine that does something. boost control? i don't know. apparently its made by pierburg who i didn't think existed anymore. anyhow, the controller itself isn't mega money for an OEM one so i'll probably just replace it since i'm there.

out.jpg

and that (part of an endless sequence of shots of the same side of an engine) is the exhaust manifold and turbo removed.

blurry old pap.jpg

here is a blurry picture of some things. if you are easily led, these are the things i just removed.

Absolutely exciting.

Next step is to remove the turbo from the manifold. I know nothing about turbos so i'll likely dispatch it off to be cleaned and have new seals and bearings and whatever. I was entertaining the thought of cleaning it out a bit myself but now its all in bits i think getting it refurbed might be for the best so i can continue to drive it around pointlessly with nowhere to go. The water-leak-selling-point in the advert is actually a bit severe now i've worked out where its from. Seems like some flange or other at the back of the head under the vacuum pump is leaking. various forums suggest this was to be expected about 100k ago so will look at replacing the gaskets in there and heater hoses which are pretty crunchy. Will take a look at that tomorrow or at least have a poke about in there.  I'm faintly tempted to send that work out to a garage as it might be messy and i feel a bit of a prick spilling car fluids all over the road.

If you have read this far: its over and you aren't in a coma.

Link to comment
Share on other sites

The turbo looks like a Garrett Variable nozzle Turbo. 

I put in 4 assembly lines in Skelmerdale to build those, but they ended up going to other European Sites. 

If the centre housing doesn't have fucked bearings, the 2 basic faults will be either the Actuator diaphragm leaking, so that vacuum doesn't move the control rod.  Or the vanes, clogging up, due to soot. 

It's relatively easy to take them apart at the turbine end and clean all the parts, but some of the parts are tiny, so can get lost. Perhaps disassemble in a plastic bag ? 

Link to comment
Share on other sites

Honestly I would say don't send it off to be rebuilt, most 3rd party places will chuck in any old bearings and may not be able to balance it properly, set the actuator etc. 3rd party Aliexpreshial cores are no good either, ask The Moog.

I would get the turbine housing off and go at it with the Mr Muscle or off brand equivalent. 99% there is nothing wrong with this turbo except sooty clag.

You can take the actuator off and try to move the lever by hand, likely to be hard/gritty to move.

The other aspect as POD sez is the actuator which is just a vaccuum can, you can test it if you have a vaccuum pump and replace the lines etc when it goes back together anyway.

Link to comment
Share on other sites

18 hours ago, New POD said:

The turbo looks like a Garrett Variable nozzle Turbo. 

It is indeed, Garrett 1949V with what were once variable vanes.

I've removed it from the manifold and cleaned some of the crap out. The Vacuum controller for the vanes is freeish but the adjuster has a range of about 1mm so I suspect those vanes are well and truly coked. I've removed the bolts for the VNT housing but its rusted shut so left soaking in penetrating oil. The turbine doesn't seem to have any play in it so might just so as Mr Q says and clean it up myself and put back together with new hoses. I'll check the N75 and adjuster vacuum in case they do want a replacement.

Need to get some gaskets in and a thousand gallons of carb cleaner for the intake manifold...

4 minutes ago, The Moog said:

Cheap Turbots havent done me any good - unless you like taking things off and back on again! 

Its not a bad job but everything so far has come apart without a fuss. I can imagine if half these bolts snapped the car would be at the scrapyard by now and i'd still be in a rage.

Its also not a job i'd want to do every weekend.

Link to comment
Share on other sites

Well done. After fannying about with our vectra just to change a 5" hose I am beginning to realise what   a drain it can be working an an ancient modern. I am not really surprised garages pass on these jobs.

Link to comment
Share on other sites

From a centre housing survival point of view the best you can do is change the oil frequently and let it cool down before you turn it off.  Oil, turns into tar otherwise. 

And lots of short journeys are to be avoided. 

In terms of the vanes. You need to make sure you cycle them. Applying full throttle at low engine speeds should cause them to close fully. 

Link to comment
Share on other sites

whilst my copper mallet won't be the same again, i got the casing apart with only most of a can of wilko fluid and much battering.

impellor.jpg

fair bit of crap on this.

crud.jpg

and this. Its quite a tarry mess and most of the vanes were sticky, only a few seriously stiff or jammed.

bits.jpg

took it apart and left all the bits to soak in some petrol overnight and i'll clean them up tomorrow.

Haven't checked to see if the mechanism is worn out yet.

Link to comment
Share on other sites

A bit late now, but my preferred method is to remove the egr pipe (the tube with the folds for bends) from the exhaust side of the turbo. Fill up exhaust side of turbo with mr muscle oven cleaner, and use a vac pump to exercise the vanes. Refit pipe, start engine, hoon.

 

Must have fixed 20 or so, including Volvos, Renaults but many VW / Audis. I keep a can of Mr Muscle in my toolbox.

Link to comment
Share on other sites

I considered this approach but it seems a bit hit-n-miss or might work for a bit then need doing in the pouring rain on christmas eve with a gun to my head.

and since i don't have anywhere to be at the moment taking it all apart and cleaning it out properly seemed to be a more comprehensive solution.

of course, if it'd snapped every bolt on the way i wouldn't be saying that.

Link to comment
Share on other sites

On 03/08/2021 at 21:28, Dave_Q said:

you can test it if you have a vaccuum pump and replace

i put a vacuum over this and it stays put, has a full range of motion. The vacuum didn't last forever but the hoses were cobbled together and just jammed in one-another so might have been leaking a bit from that.

Put everything back together on the turbo and the VNT mechanism moves from rest to the stop cleanly so once the exhaust gaskets arrive and it's not going to be pouring with rain i'll bang it back together and see what happens. Haven't checked the N75 with the vacuum pump yet but have ordered some silicone vacuum hose to replace the old ones with.

Need to take a look at the water leak situation too but works been rather draining of late. pretty sure its just going to be 1 or both of some cheapo gaskets but need to make sure its not borked pipes first.

Link to comment
Share on other sites

23 hours ago, tobyd said:

whilst my copper mallet won't be the same again, i got the casing apart with only most of a can of wilko fluid and much battering.

impellor.jpg

fair bit of crap on this.

crud.jpg

and this. Its quite a tarry mess and most of the vanes were sticky, only a few seriously stiff or jammed.

bits.jpg

took it apart and left all the bits to soak in some petrol overnight and i'll clean them up tomorrow.

Haven't checked to see if the mechanism is worn out yet.

Brings back memories, of negotiating the assembly and test equipment in Italy, in Italian.  I don't speak Italian, and I have no idea whether my translator, a manufacturing engineer from our Italian  sister company passed on all my  words. 

Mind you that one won't have been assembled in the UK 

 

Link to comment
Share on other sites

Personally I would have stuck Mr Muscle down the exhaust side. Given this turbo has been on the car for so long undisturbed, removing it will disturb seals and pipework that may end up leaking after. Sometimes it's better to disturb the least possible, especially if it doesn't need removing completely and can be done in situ. This would have been one of those times for me. 

Link to comment
Share on other sites

Interesting read this, I’ve got an old Polo TDI that loses power occasionally and this happens when the engine is under load and suddenly the car feels like it has no turbo but the EML doesn’t come on. Pull over and switch off the engine and restart and it’s fine again. Have I got a slightly gummed up turbo?

Link to comment
Share on other sites

Mine didn't throw up the EML but the turbo just stopped turboing after keeping my foot down for a few hundred meters. There was a fault code about it in the memory but no dashboard indication. I understand cycling the engine makes it go away until the fault re-occurs. If you can get to the turbo you should be able to move the actuator up and down and it should have about 10mm of movement, if it doesn't (and don't force it) then it might be clagged up? Progress without the turbo is slow indeed. again, depending on access / visibility / having a vacuum pump you can put vacuum over the actuator and the adjuster should move to the stop pin and back. Not sure what turbos went on the polo but i'd assume its all the same sort of thing on a PD diesel?

Link to comment
Share on other sites

Pics look very familiar. I had an intermittent lack of power on mine years ago (earlier AFN engine). Took the manifold off, was fairly disgusting but not blocked

2021-08-07_06-23-32.thumb.jpg.9957441bc2b2ff9de97bd7b5df111a19.jpg

Several cans of poundland oven cleaner and a wash in unleaded got me here

2021-08-07_06-23-14.thumb.jpg.c5f1bfbde6273889418f5ddf189bf509.jpg

while I was there the EGR got blanked off to try and stop it clagging up again. None of this made any difference and eventually the problem was traced to a broken cat blocking the exhaust

2021-08-07_06-28-54.thumb.jpg.de5c397992cd8180024fb3ab9cb4190d.jpg

That was "fixed" and power was restored! I left a little reminder of these mods for the MoT man to enjoy

2021-08-07_06-25-40.thumb.jpg.c60286e17cf947b91da6c17b50835b7d.jpg

I still have a fault that I think someone on here told me the cause of back in the mists of time, but I haven't fixed yet - no boost below 2000 RPM then ALL the boost. Think it's an actuator fault?

Watching with interest anyway. Think my turbo is the non variable vane type and has clocked up 256k so far. Looks fairly similar and I have that ball thingy with lots of dingy looking pipework coming off it - might have to invest in a roll of the correct size stuff and change it all

 

2021-08-07_06-34-39.jpg

Link to comment
Share on other sites

AFN is a variable turbo just like tobys.
No boost below 2000rpm does suggest actuator or more likely vacuum hose.
The actuator pulls the vanes closed to generate boost quicker at low revs, if there is no vacuum supply it defaults to vanes open which behaves as you describe.

It's either that or the turbo is clagged and happens to be stuck in that position.

Either way it's very unlikely to need more than a clean and some new hose.

Link to comment
Share on other sites

On 07/08/2021 at 06:34, bunglebus said:

lots of dingy looking pipework coming off it - might have to invest in a r

^^ I have bought rather too much black silicone vacuum hose in a few dimensions so shout if you'd like some bunged in the post.

The weather this weekend has been rather tempramental some haven't done a lot. All the gaskets arrived so its ready to go back on the car and i cleaned up the intake manifold as best i can without having access to a bathtub full of boiling brake cleaner (i assume this is what you are mean't to use?) Cleaned up the side of the head and scraped out some more clag and vacuumed out anything loose so hopefully it'll be alright. I don't think it was too badly caked up in there, plenty of crud but not enough to make me think it was being strangled. Replaced all the vac hoses i could see. Weather looks better in the week so might tackle the job in parts and get the exhaust side bolted back up. Then controller bits. then intake. over lunchtimes and evenings. Haven't yet tested the n75 controller but i think thats easily doable in-situ.

Link to comment
Share on other sites

Lashed the heavy bits back on with new gaskets so all thats left is the airbox and pipework. had a brief chat with a neighbour who commented that he didn't much like Edd China on Wheeler Dealers and that Mike was much more fun. takes all sorts i suppose.

Link to comment
Share on other sites

took it out earlier and under boost there was a whining noise. not ideal. came home. googled the answer and one was loose manifold bolts. this reminded me i may have forgotten to tighten the EGR bolts at the EGR itself. lo and behold they were finger tight. knipped up and whine gone.

boost is back car seems to accelerate fine and managed a smoky 1st gear getaway to the grimace of the environment.

Probably should look at that water leak now...

Link to comment
Share on other sites

So next on the fixing things front is the coolant leak.

PXL_20210815_142503525.thumb.jpg.0ef9fd335b3eb996d745ade2803c43d5.jpg

Chuckles here is all wet (doesn't smell like diesel), but this carries on onto the bellhousing and into the clutch (clutch judder cause? i doubt it). The flange mates with a receiver bit that is attached to a hose. The plan is to replace just this plastic section - need to check that the replacement actually comes with the oring but i think this should be doable. Access is pretty sad though.

This whole thing forms parts of a larger assembly but that seems fairly dry so i'll leave alone.

Link to comment
Share on other sites

Had a hangover yesterday so didn't do anything but today, with a yellow warning of rain, i took on the water leak. I might still be hungover as all the photos are focussed on the wrong thing.

flange.thumb.jpg.58af67a6913c1c43285aeb4dd7d9d91a.jpg

any how, this rust 'n' black bit is the old flange, its just three 10mm nuts and pops out. access is pretty crap though as its below the vacuum pump at the back in the middle of the engine so much stretching was required.

seal.thumb.jpg.8b46f6c61ca9ddb52dc7942b1254973f.jpg

I don't want to jump to conclusions but the presence of bathroom sealant is usually a good indication that this is completely factory...

1819396366_morewear.thumb.jpg.1d414edf9d06f1399693f2009f8df0fd.jpg

It absolutely wouldn't budge from the coupler for whatever it is attached too, there is a little spring clip i removed but it in the end pried it out like a fucking savage. Looks like the inner lip has seen better days.

wear.thumb.jpg.748e51f0e90a918c5975481cba280599.jpg

not liking that mark poorly circled in red, the coupler this fits into is only available, from vw anyway, as part of a larger assembly and they don't sell the oring that lives in there separately because of course they don't. autodoc do one so if leaks i'll swap it out with one of those.

anyhow, the new flange fitted into the old coupler without any force (which concerns me) and i've sprung-clipped it back and finger tightened the flange nuts down. Its now absolutely hammering down so i'll finish it all up later or tomorrow.

Link to comment
Share on other sites

Put 60 or so miles on this now and its holding its coolant and the joint / rest of the block is dry so tentative that thats that. The car smells of diesel when idling or slowing / in slow traffic which isn't great for the old lungs. I'd noted that a breather pipe was a bit suspicious in its level of grot for being no where near anything that makes grot and lo and behold.

pipe.thumb.jpg.30c7385133de3a7114a09d21c93e1719.jpg

breather pipe from the rocker cover to the intake (post MAF for bonus points) is a bit haggard. Hopefully that'll see the smell gone and empeegees skyrocket. exciting times indeed.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...