allroad V6 TDI slow build

[gldgti]

Got one head together today and all the turbo stuff done.

https://youtu.be/foHDqWEHeWk

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[gldgti]

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[gldgti]

So what happened here with my allroad build?
Well after a big weekend putting the engine back together with all the new bits, I ended up pretty deflated when I only had compression on 3 cylinders.
I got the ****s with it and bought a v5 bora to drive in the meantime while I figured out what was wrong.
After a month I built up the gumption to pull the heads off again, assuming I'd rushed the valve job and buggered it.
So, last weekend I re lapped all 24 valves and vacuum tested all of them before torquing down the heads again, assured they would be perfect.
By Wednesday night I had the timing belts back on, so I could turn it over by hand and check for compression.
Imagine how I felt when this time, I only had compression on one cylinder.
It's then I realised that I was probably not my lapping skills that were the problem. Rather, the tolerances of all the new parts (cams, valves, rockers, lifters) adding up to hold the valves open!
Today I confirmed this by pulling vacuum on the ports with the cams torqued down, and then after loosening the bearing caps 1/4 turn... That's right, 0.25mm is all it took to close the valves.
I didn't particularly want to pull both heads again ( $300 in bolts and gaskets each time) so I could grind the valve stems down, so I found I could grind down the tip of the cam follower instead and achieve the same results. Ask me if this was a good idea in a year or so I guess! But I can replace the followers easily any time... Pulling the heads is something I just don't want to do a 3rd time right now!

Anyway, I managed to modify 12 followers on 1 head this evening, and get it all back together so that I could pull vacuum on the intake ports with the cams torqued down and finally, success!
I'll do the other head tomorrow and put the car back together next week.
So relieved. Damn tolerances!
I did measure the new valves, they are all within tolerance, however they are all at the higher end of the range.

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[brad]

Well done you. Character building to say the least.

[gldgti]

Yes, that's one way to describe it!
I am pleased to report good compression when turning over by hand now. Finally I can put it back together!

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[anthony--t]

Just fulfilling the 'slow build' part of the thread title

Good to hear it's assembly time.. again haha

[gldgti]

It lives!

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[anthony--t]

Please elaborate...

[gldgti]

Got it going Thursday night and took it to work Friday.
Apart from a couple of teething problems its been good so far.
It's pretty much the same as before, but smoother and has more power at the top of the rpm range.
Once I happy with it I will swap in the bv50, hehe

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[gldgti]

Also, the cold idle is beautiful and smooth.

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[gldgti]

So a bit of an update.
I took the car up the coast over the weekend - it performed flawlessly and I was all back in love with it.
Yesterday morning I jumped in and left for work. After about 5 minutes the car starter to idle really weird (high, around 1300rpm) and I get esp, abs lights on the dash. Gear changes are all rough and tumble.
So I took the golf to work and scanned for codes after I got home. Got 2 error codes apiece on abs and trans control module, plus 3 on the engine including a persistent coolant temp sensor error.

I changed the coolant temp sensor tonight and bingo, car runs perfect again.

Fancy that a coolant temp sensor fault could cause all that woe!

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[sports racer]

That's why my MK1 is getting twin carbies. The only engine electrics will be in the dizzy.

As much as I'd love to fit a modern turbo diesel I hate not knowing what to fix when the engine has a cough.

Cheers

Paul

[gldgti]

It's not a huge deal - didn't take long to diagnose, but its surprising the flow on effect from just the one failure.

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[gldgti]

So I'm now very happy with the Audi once again. Running very well and today I've ordered new engine mounts and front driveshafts to freshen up the driveline (split CV boots and engine mount fault codes popping up recently).
I have also begun a little work on the turbo conversion bits and bobs, sorting out some small issues. One of them was a bit of a leak between my adapter and the new turbo, which is really down to me only half doing the job in the first place -hehee.
I'm not using gaskets between the manifold, adapter and turbo. This means the mating surfaces need to be nice and flat.
To acheive this, I'll be wet sanding the adapter on a bit of granite bench top like so:
You can see the leaky bit, just on the top left edge of the triangle. Lots more sanding required yet. Unfortunately stainless takes forever to sand like this.

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[anthony--t]

yay! keen to visit you soon!