Light Silver TDI Sport - Refresh and repair

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whitbytom

Member
Following on from my intro thread I thought I'd follow on with my forays into fixing and improving my little silver bullet...

I got my hands dirty on the car for the first time yesterday, I wasn't overly shocked by what I found and I now have a list of parts to buy. It's getting the full service treatment, cam belt, tensioner, idler pulley, water pump, thermostat, oil/air/fuel/pollen filters, accessory belt, fluids etc.

The undertray was a bit of a random mix of fixings but it's secure so I will address that later. There are no scary oil leaks and I've identified the dead oil level sensor so I'm going to order a genuine replacement. I can see some new parts under there which back up all the receipts I have with the car, and I put a nut and bolt back where cable ties have been used to hastily secure the bottom coolant hose in the past.

One thing that has irritated me since I got the car is the quiet droning noise under the dash that seems to be vacuum related. I think I've traced it to the boost control valve, when you grab it it's vibrating at idle and then stops when the throttle is pressed, when the vacuum drops. It's the valve set back in the centre in the photo below if anyone can shed any light?

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When all the service parts arrive I'll update with any progress - I've ordered a PD timing pin kit to help me to do the belt, any tips/tricks for that job are most welcome!

Tom
 
Strange. The left most valve is the N239 known as the anti shudder valve. This lets the diesel engine shut off cleanly. The middle valve is the N18 valve and this controls the position of the EGR valve. The one on the right is the N75 and this is the one that controls the turbo boost pressure.
 
audifan said:
Strange. The left most valve is the N239 known as the anti shudder valve. This lets the diesel engine shut off cleanly. The middle valve is the N18 valve and this controls the position of the EGR valve. The one on the right is the N75 and this is the one that controls the turbo boost pressure.
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You're right - I've printed off this page:

https://audi.7zap.com/en/rdw/audi+a2/a2/2003-248/1/131-131010/#18

I'll go over all the vac lines with the diagram and look for leaks over the weekend and go from there. I remember from my old PD130 engined golf the vacuum system was a hot mess so I suspect this will be much the same.
 
N239 and N18 are vacuum operated N75 is pressure from the turbo. Even a very small hole, perished or loose hose or fitting can be a problem. Check carefully where the braided rubber hose are fitted over the thin plastic tubing.
 
The sound may be the mooing noise that the tdi's like to make i think it's one of the valves n75 possibly that's bolted to the bulkhead. Best to make some new rubber mounts so it's not directly bulkhead mounted this should stop this noise. There is a thread somewhere on the forum that has instructions
 
I investigated a bit more this evening, the droning noise in the cabin is definitely coming from the N18 valve. When I disconnect the vacuum hose between the T piece under the valve that leads to the N239 anti shudder valve, the noise from N18 stops (and the revs raise slightly because I've caused an air leak)

1659731734529.png
 
Took it for a run up to the Lakes on Saturday and it didn’t get above 70 degrees in spite of the traffic. Picked up a new thermostat and fitted that Sunday, comes up to temperature fairly slowly (as I think these engines do) but sits at 90 spot on now when it’s warmed up!
 
The little A2 has really started earning its place in the household now, and has provided ice cold air conditioned luxury in the hot weather, which is more than any other car on the fleet can claim!

So to reward it, I splashed out on a load of parts and braved the heat yesterday to give it a thorough service. It got:

Gates cam belt, tensioner, roller and water pump (full kit)
Gates multi rib belt
Fuchs 505.01 oil service, with filter
Gearbox oil change
Air filter
Fuel filter
Pollen filter
Genuine oil level sensor

I'm glad I bought a timing pin kit - it timed up perfectly and I didn't have to mess with the cam sprocket. I might get the torsion values checked to be certain they're right.

1660566416733.png


The belts were definitely past their best:

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The old boy who lives next door stuck his head over the fence just as I'd finished the cam belt, said he hated to see a man suffer, and handed over some timely refreshment!

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I've spotted a few vac lines under the turbo that look past their best so have ordered some silicone hose to replace that, then I'm looking forward to driving it knowing the major service items have been addressed!
 
Looking good! You’ll feel much better using the car knowing all this has been done.

How many miles has it done? If more than around 130k consider changing the oil pump chain that drives the balancer shaft along with its tensioner at the next belt change - or else listen for a tinkling sound and vibrations at lower revs that could point to this needing doing sooner.
 
dj_efk said:
Looking good! You’ll feel much better using the car knowing all this has been done.

How many miles has it done? If more than around 130k consider changing the oil pump chain that drives the balancer shaft along with its tensioner at the next belt change - or else listen for a tinkling sound and vibrations at lower revs that could point to this needing doing sooner.
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Thanks! The car has done 135k, I've investigated for the symptoms of the chain/tensioner failing and can't find/hear anything that concerns me massively. Given that I believe the parts for that job are upwards of £175 and at this point I'm already well over £200 deep on service and replacement parts, I think I'll save that one for another day. I'll probably take off the sump on the next oil service (there is evidence it's been off before) and investigate further.
 
The car continues to soldier on on daily duties and I've braved the weather to address a few other niggles.

A few weeks ago the temperature gauge suddenly died altogether, so from a steady 90 degrees warmed up I had no gauge at all. I ordered and fitted a proper Beru temp sender (not a pleasant job, but the old one was an unmarked aftermarket thing) and now the gauge is back in action, but the temperature is struggling to get much above 75-80 degrees. Even working hard on long motorway climbs fully loaded it reaches 85, and running around town it rarely gets much above 70. I know the cooling system is good, it's had a water pump and a new thermostat, I would have thought it would reach 90 eventually?

I replaced the N75 valve (a proper one from Murrays) as the existing one was ticking loudly when energised, the new one has cured that, although i have a vacuum related droning noise coming from the dash area, the drone stops when engine vacuum drops but it is really starting to irritate me. I replaced any suspect pipes in the engine bay back in the summer, I think I need to investigate under the dash.

In the last few days I have noticed what I suspect to be a fuel leak - the economy has dropped by 8-10mpg (measured on fuelly) and there's a distinct diesely smell coming from the engine bay. Are there any common places where they leak?
 
Tandem pump is first place to check, to right of engine block where fuel lines go in. (it also generate vacuum as well as deisel supply). If its more fumes check for dirty leaking along back of cam cover where you ahve EGR valves and EGR coolers etc..
 
I would check the temperature readings using VCDS or similar - it sounds like your new thermostat is faulty, although I know that won't be a welcome prospect.
 
Having run well for nearly 5000 miles, the car decided to give me some grief. The alarm had been sounding randomly at certain times for a while, but the problem had got worse to the point that the car was waking me up at 4am and neighbours were complaining of the row. The problem was so bad I was barely able to use it and leaving it unlocked on the driveway overnight to avoid annoying the neighbours.

A frantic message to @timmus was sent and he was really accommodating, so I took the car up to Timmus towers 2 weeks ago. What can I say, Tom was a true gent. He quickly diagnosed and fixed my alarm issue and then moved on to identifying and fixing a host of other niggly faults with the car, all while being a very interesting and knowledgeable guy to chat to. He's an incredible asset to this forum and I will definitely look to use his services again in the future.

I admit I was having a wobble with this car, the niggles coupled with the fact my wife hates the car had me seriously considering putting it up for sale. Tom's love for these cars is genuinely infectious and I came away with a new found appreciation, plus if my wife refuses to drive it I never have to adjust the seat and the mirrors when I get in 😄
 
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