Finding and preparing a new to me AMF

rotifer said:
Hi,
I agree, use bosch injector seal kits or similar brand.
My apologies for moving off topic, you were talking about the lower seals at the tip of the injector unit.
I am graetful for your reply.

Measuring the indentations in the well walls to establish their diameter is good advice.
The shape may not be circlular but the o-ring should accommodate this. I guess viton seals would work in this application if oversize required?
I need borescope to inspect the lower o-ring well wall.
Is it possible the injector body has made the indentations due to a slight sideways force exerted by the hold down clamp?

Hypothetically speaking the lower seal could be damaged right from go. As when nstalling the unit it may not be diven into the injector well evenly.
There is probably mechanics hack to reduce the likelihood of this. Apply engine oil to the o-rings and well walls and gently drift the injector down in stages at the opposite side to the clamp to overcome the well wall ridges?
Your build is fantastic and a great read.
Cheers!
Click to expand...
Maybe use diesel as the assembly aid?
Mac.
 
Thanks Mac,
Sounds like an option.

I found this document here post number 2 details on 'how to' in the document.

I've been installing an injector not exactly to spec.
I've not been very careful and used the clamp to push them down. 😣
Screenshot_20240112_143433_Adobe Acrobat.jpg
 
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I think I said I would post this picture for somebody? All three injectors, all equally worn with equally worn O rings:

IMG_0915.JPG



This is one of my bad running 170k miles injectors. The lower red O ring has given up and started melting:

IA2 Head 16.jpg


Wear on one 170k mile injector:

A2 Head 15.jpg


It is the same as the 100 k injectors but deeper.
 
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Finally got all three pistons clean. They all show signs of wear / erosion but I think that has been caused by carbon deposits and the pistons are good:

IMG_0916.JPG


I just want to do a couple of checks for wear before putting them in storage:

Piston ring.jpg


Piston ring gap 0.4mm, that's good.

IMG_0919.JPG


Ring to groove clearance 0.15mm. worn but not worn out

IMG_0917.JPG


I now need the opinion of an engine remanufacturer on the bores but first I will check the valve guides for wear.
 
philward said:
Finally got all three pistons clean. They all show signs of wear / erosion but I think that has been caused by carbon deposits and the pistons are good:

View attachment 117809

I just want to do a couple of checks for wear before putting them in storage:

View attachment 117806

Piston ring gap 0.4mm, that's good.

View attachment 117808

Ring to groove clearance 0.15mm. worn but not worn out

View attachment 117807

I now need the opinion of an engine remanufacturer on the bores but first I will check the valve guides for wear.
Click to expand...
Hi Phil,
Where are you measuring the 0.4 mm as the second photo appears to show the piston behind the ring after Insertion
but the feeler gauge is twisted through 90 deg to my eyes
Hope that helps
Keith.
 
kp 115 said:
Hi Phil,
Where are you measuring the 0.4 mm as the second photo appears to show the piston behind the ring after Insertion
but the feeler gauge is twisted through 90 deg to my eyes
Hope that helps
Keith.
Click to expand...

Hi Keith
The feeler gauge is in the gap in the ring. I think what you can see is the reflection of the ring on the gauge perfectly matching the ring to make it look like the gauge is behind the ring. It was difficult to photograph, job done as the illustration from the manual.
Phil
Edit, measuring he ring gap 15mm from the bottom of the bore puts the ring in an unworn part of the bore so gives a true measure of ring wear. The same measurement 15mm from the top was 0.5 mm indicating a small amount of bore wear.
 
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Good news this morning, the head is good so no machining of valves is required. I've removed the valves and seals and checked for valve guide / valve stem wear.

Valve.jpg


I was so confident they were good I didn't bother to set the gauge up correctly. I just held it on a block and rocked the valve from side to side.

IMG_0922.JPG


0.6mm comfortably within tolerance. Just flatness to check then the head can be cleaned and reassembled
 
This task is proving far more problematic than I expected:

A2 Cylinder Head.jpg


I ordered a precision steel rule but overlooked the word flexible in the description. The necessary rigid steel rule has arrived today. 0.1mm is very little and I'm finding the slightest trace of head gasket is throwing out my measurements Checking is now waiting on me thoroughly cleaning the head.
 
CrispyEdd said:
It says you can't skim the head?? Why not
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Good question as the heads are skimmed in the factory, fly cutter marks are visible. Also if the valve guides had been worn the only corrective action advised in the manual was to fit new valves. If that failed then the solution was, as in this case, a new head. So in the case of excessively worn valve guides or a head warped more than 0.1mm the Audi solution is a new head. The head is probably NLA.
I’m no diesel expert but having taken some measurements I have an opinion. Let’s see if somebody more knowledgable comments before I speculate.
 
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Head now clean, I used a new stanley knife blade lubricated with silicone spray to scrape off bits of gasket and carbon and then rubbed down with a fine Scotch Brite hand pad. It is an aluminium oxide abrasive pad but it does not produce the grit you get with abrasive papers. I wanted to keep grit out of the oil and fuel ways.
The spec is no more than 0.1mm of distortion so I used a 0.09 gauge. It didn't even come close to going under the rule. It was checked across the width and also along the length in several positions. The head is flat.

IMG_0927.JPG


Any diesel experts able to advise why if it had not been flat it could not be skimmed?
 
philward said:
Head now clean, I used a new stanley knife blade lubricated with silicone spray to scrape off bits of gasket and carbon and then rubbed down with a fine Scotch Brite hand pad. It is an aluminium oxide abrasive pad but it does not produce the grit you get with abrasive papers. I wanted to keep grit out of the oil and fuel ways.
The spec is no more than 0.1mm of distortion so I used a 0.09 gauge. It didn't even come close to going under the rule. It was checked across the width and also along the length in several positions. The head is flat.

View attachment 118058

Any diesel experts able to advise why if it had not been flat it could not be skimmed?
Click to expand...
Hi Phill,
It’s probably due to the extreme pressure that the PD generate 32,000 psi I think reading in the technical docs which is all in the head.
Regards
Keith.
 
Filthy awful job, squirt in brake cleaner, scrub with bottle brush. The valve seal insert tool is there to stop muck getting down the valve guides. If you do this job start will all 3 exhaust ports, saves transfering crud from the inlet to exhaust ports.

IMG_0928.JPG


Nice and clean in there:

IMG_0929.JPG


I did notice more wear on the exhaust valve guides, I need to check I checked the lateral movement on an exhaust valve.

Edit, yes it was an exhaust valve I checked, back to steaming the outside and start thinking about reassembly.
 
robskiA2tdi said:
inspired with your post @philward just bought myself ATL engine, engine stand to keep me busy over winter months, I very like this thread. Need to get workshop manual now.
Click to expand...
If you search on this forum the question of manuals has been asked several times. Genuine Audi manuals can be accessed for a time limited fee, but there is time to download the manuals you need; I think? I'm not sure what the site is called.
 
philward said:
If you search on this forum the question of manuals has been asked several times. Genuine Audi manuals can be accessed for a time limited fee, but there is time to download the manuals you need; I think? I'm not sure what the site is called.
Click to expand...
thx @philward, I think\hope it would be same source I've used for my VWT5 to get manuals from
 
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