What's in the workshop this week? Jim's black Final Edition

[MikkiJayne]

That's just how they are when they are new Same material as far as I can tell, but younger and less brittle obviously. The aftermarket pads are slightly more brown than the new genuine ones but seem to be also the same material.

The old pads in Stephen's are exactly the same colour so I think its more to do with the material ageing than picking up dirt from the oil.

[The_Laird]

It’s starting to go back together again. How exciting!

Were the old tensioners visibly knackered, or can’t you really tell - apart from the rattle?

[MikkiJayne]

There are no visual clues which ones rattle and which ones don't unfortunately.

I have discovered something interesting though - there is a tiny wire gauze in the oil feed to the tensioner to stop debris getting in. Odd, since the oil filter is much finer, but they do trap debris so they obviously have a purpose. On many of the tensioners I remove, this gauze is either broken or missing, which means it has gone through the tensioner! Now debris or not, a small chunk of stainless wire going through something containing rubber o-rings is not going to do it a lot of good! I have a theory that when this gauze disintegrates, this is what causes the tensioner to start rattling since it trashes the o-rings. On that basis, they may well be better off without the gauze and just take the tiny amount of debris that turns up. I will build an engine up like this in the summer and see what it does long term.

Curiously, this is a known issue with the W engines, except in those the gauze apparently ruins the tensioner rather than just making them rattle. It's a $10K job for the W8 Passat at dealer rates!

Another job for the summer is to build some sort of test rig for the tensioners. I plan to saw the end off one of my trashed heads and just use a couple of cam lobes and a tensioner to see if I can test good/bad/indifferent. That will also be useful if I can figure out how to rebuild them too.

[MikkiJayne]

These are the two old tensioners. Note the broken gauze on the right hand one. I wonder if it was only this one rattling because it's eaten some stainless steel wire? I might put the left one in another engine and see what happens.







Last nights update a little late:

The temperature sensor is totally rusted in to its socket. With overheating issues we're changing this as a precaution, plus with it seized in like this it would be a nightmare to change later on with the engine back in.





It has to be destroyed to get it out



The o-ring was totally perished and crusty so just as well we're changing it



Socket cleaned up ready for the new sensor



Water pipes back on the engine



This is my tool for fitting the crankshaft seal. Its a piece of exhaust tube that fits perfectly inside the old seal so it can be used as a drift to push the new seal in.



The bushing that drives the oil pump is swapped back to front when fitting a new seal so that the seal lip has fresh steel to run on. After 185K miles the rubber seal has worn a noticeable groove in the steel bushing



Timing gear all back on

[MikkiJayne]

Tonight's progress:

I don't know why people say the oil cooler pipe is really difficult. Just turn the engine on it's side The aluminium cooler pipe is fitted to the block here





This is the old plastic pipe - split at both o-ring grooves so the o-rings were stopping it leaking for now



Oil cooler housing back on



I removed and cleaned the oil pump pickup gauze but forgot to take a before pic! It had a few chunks of carbon debris and old silicone sealer in it so I cleaned those out and put it back together



Not many people get to see their engine like this Its so much easier to do the sump like this though!



Cleaning old silicone out of all the bolt holes is most vexing!



Sealing flange all cleaned up



Sealant applied



Bolts torqued and a nice even-ish bead of sealant all round the sump



This damn oil sensor! This was leaking because the seal (missing from the pic sorry) was perished but you can't buy the seal on its own - you have to buy a new sensor for £loads Luckily I had a duff sensor with a good seal in left over from the sump I got from A8parts for Stephen's car so swapped the seal over and put the good sensor back in



I subconsciously registered that there was something odd about the oil filter housing when I took it off, but only twigged what it was when I went to put it back. Jim's on the left, a spare of mine on the right. The support structure for the filter is missing! Its not in the old filter which means at some point in the past someone has managed to snap it off when removing the filter and 'not noticed' I sense another call to Maria in my future...



One thing that really annoys me about these cartridge filters is that its impossible to fill the filter with oil when changing it. This means on restart the engine is starved of oil pressure for a moment while the pump fills the filter.

With the engine upside-down I can pre-fill the filter, so I do



Back together with my spare filter housing which I shall replace with one from A8parts



It'll stay upside down overnight to allow the sump sealer to set completely before refilling with oil.

[Nognar]

Love that, great work.

Mine at 197,000 probably needs the D2 Doctor Platinum service in the near future.

[MikkiJayne]

The 'valley pan' gasket has been bugging me a while - it's responsible for all the oil under the inlet manifold, but has been on back order. Luckily, it arrived this morning

This is the old one - no re-using that!



New one in place



Cover on



The knock sensor plugs disintegrated as I removed them, which is a very common problem.



New Bosch sensor in place, hiding under the inlet manifold





The other one is easier to get to



The viscous fan bearing was worn out and very noisy. £loads for a new one and also on back order, but luckily I had a low mileage used one in stock



Removing the engine from the stand since I don't need to turn it over any more



and back on the separating table so I can get to the crank main seal, then it can be reattached to the gearbox

[moltuae]

Originally Posted by MikkiJayne

New Bosch sensor in place, hiding under the inlet manifold

Ah, so that's where it lives!

I had one fail a few months ago. Fortunately it was the other one, which is much easier to get to, but I bought two new ones and asked the garage to replace both. They replaced the faulty one but decided to leave the other one because they couldn't find it. We guessed that it might be under the inlet manifold but I couldn't find any info or photos confirming it.

[David's8]

Originally Posted by The_Laird

Let’s name and shame, shall we? The “gorillas” who did the last belt change were from AudiTechnik in Glasgow. Thanks guys!

That'll be the same crowd whom you got to change the belt on my car when you owned it and didnt change all the pulleys/tensioners and didnt use "genuine Audi parts" as they specify in the adverts..........

Fantastic and informative thread MJ
At 115k I think that mine needs a thorough look at in the next year.

[ainarssems]

The viscous fan bearing was worn out and very noisy. £loads for a new one and also on back order, but luckily I had a low mileage used one in stock

Have you looked into changing bearing(s) for it? Mine is noisy as well, not sure if PF and FL is the same. New ones from dealer too much money and I don't think there are any aftermarket alternatives.