SuperbTWM

Needs an internal inspection, that or put a water pump and belt on it and turn it over by hand and see if it locks up Mileage? when was pump last changed?

Belt is reccommended but the pump has never been a service item which is why they design the coolant to 'last forever' as some will choose not to change the pump, especially average people who won't see the value in changing it just in case. I have removed my 'Mit Silicat' expansion tank but mine was actually in some sort of plastic repository rather than a tea bag but didn't want to chance it. I will go ahead and do the coolant with the water pump every 4/5 years and I think that will be more than fine.

Just to clarify, when I said 'start pottering about' i'm refering to driving the car around steadily, not reorganising your stamp collection 😂 Plenty on youtube that are even VAG specific, there is more than one way to skin a cat mind. If you have VCDS and the 2.0 TDI with the complicated cooling system you can enable the water pump/s manually to try and help burp the system as well.

Never had any issues purging VW cooling systems, especially now they get to operating temperature at tickover if you have euro 6. Get as much coolant in and air out as you can while the engine is warming up at tickover, then start pottering about until everything is hot adding coolant as necessary. Don't be surprised if you are still topping up by small amounts for the next month or so so carry a bottle with you just in case. I believe if you had a totally dry engine/radiator and charge cooler system then using a vac filling adaptor would be worth doing and you can get one for around £75. (obviously you need a decent volume of compressed air for this also) But typically just dropping the radiator hose or taking the water pump out only drains part of the systems anyway. Also, IMO use the G12 evo.

It's a good job really, the Passat of the same vintage was a bit of a barge, also had a front suspension set up that consisted of 4 arms per side rather than 1, pricey to replace and a nightmare to diagnose a knock wheen there are an extra 3 ball joints!

Give it some Hammerite!

I think this is what my Passat is like, there is something after the turbo but it isn't not big enough to be the DPF and it can't be the main SCR catalyst because it's before the DEF injector. I do have a failure of the post SCR NOX sensor also, seem to be quite an expensive part as well ☹️

Maybe there is a restriction/blockage in the charge air coolant cooler/radiator? I believe the charge air coolant cooler/radiator is behind the air con condenser but in front of the main radiator. Are the fins on the condenser straight and clean (IE not reducing the airflow through it and subsequently the charge air radiator) What are the amibient temps when this happenning? Also, what is the speed limit in Portugal??? 😂 I'm willing to bet if you try not going over 100mph in the blistering heat everything would probably be fine

Are you saying that all was well before the incident on the motorway? Seems very strange to have a sudden failure that has physically damaged the DPF to that extent. 28K is not a lot for 4 years use at your time of purchase, maybe repeated regenerations in its previous life as it pottered about around town took its toll on the DPF

Can you do the same test on HI but with the air con off? Maybe the cool blend flap is passing on the drivers side causing it to overcool, obviously turing the AC off will bring the blend air to ambient instead of close to freezing (not 100% sure this is how it works but I thought it was worth suggesting)

If it's the standard VAG sump plug then the washer comes with a new sump plug as the washer is captive (I've never had one fall off on me anyway). I believe you could get it off if you wanted though. I have never bought a new sump plug for any VAG car I've ever had and never had one leak yet.

My 2015 Mk2 had this leak from new, leaked in via the intake and dripped throught the bottom of the blower motor, dealer fixed with with sealant IIRC but never saw the repair.

What are the fault codes in relation to? I think the low pressure EGR at the back of the engine uses an electrionic butterfly valve, and the high pressure EGR valve at the front of the engine uses a vacuum operated valve for EGR flow control. Therefore if you have codes relating to a solenoid operated valve, my best guess is that on the bulkhead there will be a modulating solenoid valve that uses vacuum to control the EGR valve at the front of the engine so that is where I would look first. I could be wrong though so the best thing to do is have a good look yourself.

Sounds like the lights are somehow back-feeding the ignition. Do you have a rodent problem? Any water damage? Dodgy aftermarket stereo?

Get an early mk3 Superb if you can, even if you get a nice facelifted mk2 from 2015 its still an old dog from 2008 underneath and does handle like one.

I can't believe you had the exact tool you needed to do the job right and you have completely fluffed it up! There is not much else you can do apart from crank at this point, it will go eventually. WOn't do the HPFP much good if it has been run dry or is airlocked though

They are on a taper but im about 80% sure they are splined somewhat presumably to reduce the chances of them slipping rather anything else.

I had this issue on my Passat but there is a plastic deflector on each side of the windscreen it was hitting rather than hitting paint causing an annoying tap. It seemed at first that the bottom of the wiper wasn't travelling over the bottom of the screen smoothly causing the top to kick out but no amount of cleaning the screen seemed to sort it. It sat in the parked position too well to be out by a spline but ordered a puller to properly investigate. In the mean time I put a pair of gloves on and gave the wiper arm a tweak, its very rigid but managed to move it enough to never have it hit again. Yes, I know I am a rough a**e

save yourself £70 and buy a £5 brake fluid tester, I bet you have part exchanged the car before it actually needs a brake fluid change.

Run it without the aux belt, it will either confirm or rule out the alternator, tensioner or air con compressor.

Not a bad idea for the price of them, if you do though it is worth at least plugging them into the car because I have had them dead on arrival before.

I hope you have more luck with cheap sensors that I have, I would go OEM every time, it saves a lot of hassle 😉

If the code comes back immediately without movement I think it would most likely be the sensor, but then again a large shock is more likely to damage the bearing than the sensor . I'm 50/50 at this point.

This gives a fairly good overview of all the main control and emissions systems: https://pics.tdiclub.com/data/517/820433_EA288.pdf

As has been disussed previously, this engine has 2 EGR systems high and low pressure complete with control valves and coolers for each, it still has the same throttle butterfly but with an additional throttle butterfly in the exhaust as well for added backpressure for even more EGR goodness, this might be worth a check to make sure is not suck but im sure the car would let you know via the EML. The majority of the EGR flow comes from post DPF so intake should be relatively clean compared with pre 2015 Euro 5 variants. I agree a cheap endoscope would be handy to have a look inside and up at the cooler, would be interesting to see how much build up there is. I am sceptical that this sort of build up would cause any sudden economy issues though, it would probably be much more gradual and not noticeable. Have you scanned for fault codes recently? Have you jacked up each corner to make sure the brakes are not binding or felt for excess heat after a long drive?