2.0T Engine Rebuild; Story, Plans, Advice, and Results!
11-18-2014, 10:29 AM
#1
AudiWorld Newcomer
Thread Starter
Join Date: Apr 2013
Location: Roc
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
2.0T Engine Rebuild; Story, Plans, Advice, and Results!
Hey fellow lovers of all things Audi!! Firstly, the story:
2007 Audi A4 Quattro, APR Stage 1
Since I bought my A4 (a year and a half ago at 97k) I noticed that it burned an unusually large amount of oil. ~1L per 800-900 miles. Also, if driving in city areas too often, upon highway demand it would stutter a bit and spew black smoke, then all would be fine. I assumed that oil was getting either past the valve seals or the piston rings, and without a clear diagnosis I just decided to leave it be. Firstly; learn from my mistake and don't do this. It becomes a headache once whatever's failing finally gives up.
About 3 months ago (now at 126k), i'm driving and a CEL comes on. It says "Massive EGR leak". So, I replace the N80 valve and the PCV and that doesn't help. One week later, I'm driving and it starts running really rough, like one of the cylinders is just plain not firing. I got it tested at Audi and they found that Cylinder 3 had no compression at all. So, difficultly, I drive it home and started disassembling everything. I knew something was up, and I was right!
Turns out, after full front end disassembly, engine pull, and strip down, that my #3 piston FREAKING CRACKED at the piston skirt and a piece of the piston and my rings in that spot all went down into the oil pan (somehow making it past the oil pump and balance shafts because there's no damage to them or the oil pump). I'm not sure which (piston or piston ring) failed first, but I just know that both failed. At this point it doesn't matter...
Luckily, it didn't score the cylinder wall too deeply so I should be able to have it bored and honed and I'll be buying new JE pistons at stock CR, getting them coated with low friction side coatings and top coated with heat reflective. I'll also be installing Calico-coated main and rod bearings. I won't be replacing the rods because they seem to be really mint.
This bottom-end (parts and work) will cost me $1345.
The part I'm undecided on is whether I want to trust that (with 126k miles) the valves, springs, seals, guides, and lifters are all ok or if I want to replace all that with performance parts and KNOW that everything is buttoned up. It does seem like the valves don't seal 100% and let some air leak by, but I'm not sure if that's just because of carbon buildup and maybe cleaning will regain the seal. However, cleaning won't save valves springs that might be close to failing.
That head (parts and work) will cost me $1630.
What would you do? What would you suggest I do? Try the head as it is and see if it works and take it off later if something's wrong? Get it tested? Go ***** out and get all this work done since it's all apart?
Looking for your experiences, feedback, and advice! I'll post pics of the damage and all the heinously beautiful new parts. Hopefully I'll get a video of it once the engine's back together and everything's fixed.
2007 Audi A4 Quattro, APR Stage 1
Since I bought my A4 (a year and a half ago at 97k) I noticed that it burned an unusually large amount of oil. ~1L per 800-900 miles. Also, if driving in city areas too often, upon highway demand it would stutter a bit and spew black smoke, then all would be fine. I assumed that oil was getting either past the valve seals or the piston rings, and without a clear diagnosis I just decided to leave it be. Firstly; learn from my mistake and don't do this. It becomes a headache once whatever's failing finally gives up.
About 3 months ago (now at 126k), i'm driving and a CEL comes on. It says "Massive EGR leak". So, I replace the N80 valve and the PCV and that doesn't help. One week later, I'm driving and it starts running really rough, like one of the cylinders is just plain not firing. I got it tested at Audi and they found that Cylinder 3 had no compression at all. So, difficultly, I drive it home and started disassembling everything. I knew something was up, and I was right!
Turns out, after full front end disassembly, engine pull, and strip down, that my #3 piston FREAKING CRACKED at the piston skirt and a piece of the piston and my rings in that spot all went down into the oil pan (somehow making it past the oil pump and balance shafts because there's no damage to them or the oil pump). I'm not sure which (piston or piston ring) failed first, but I just know that both failed. At this point it doesn't matter...
Luckily, it didn't score the cylinder wall too deeply so I should be able to have it bored and honed and I'll be buying new JE pistons at stock CR, getting them coated with low friction side coatings and top coated with heat reflective. I'll also be installing Calico-coated main and rod bearings. I won't be replacing the rods because they seem to be really mint.
This bottom-end (parts and work) will cost me $1345.
The part I'm undecided on is whether I want to trust that (with 126k miles) the valves, springs, seals, guides, and lifters are all ok or if I want to replace all that with performance parts and KNOW that everything is buttoned up. It does seem like the valves don't seal 100% and let some air leak by, but I'm not sure if that's just because of carbon buildup and maybe cleaning will regain the seal. However, cleaning won't save valves springs that might be close to failing.
That head (parts and work) will cost me $1630.
What would you do? What would you suggest I do? Try the head as it is and see if it works and take it off later if something's wrong? Get it tested? Go ***** out and get all this work done since it's all apart?
Looking for your experiences, feedback, and advice! I'll post pics of the damage and all the heinously beautiful new parts. Hopefully I'll get a video of it once the engine's back together and everything's fixed.
11-23-2014, 10:54 AM
#2
Sorry to hear about the damage. What do you mean by parts and "work"? Are you quoting the labor cost for someone else to fix them? Why miss all the DIY fun 
Good luck anyway. If you don't have it, search and download (BitTorrent) ElsaWin 3.6 manual. It will save you a lot of guess work.
Good luck anyway. If you don't have it, search and download (BitTorrent) ElsaWin 3.6 manual. It will save you a lot of guess work.
11-23-2014, 04:47 PM
#3
AudiWorld Newcomer
Thread Starter
Join Date: Apr 2013
Location: Roc
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
By "work", I mean bore, hone, and resurface (few thous) on the block and 3-angle valve job, press out/in valve guides/seals, and resurface of the head. All the part installs (including pistons, rings, rods, bearings, crank, cams, valves, valvesprings, rocker arms, and lash adjusters etc.) and full engine install will be done personally! 
Yeah, thanks for the info about the ElsaWin, I'll have to try to check that out. So far, I've used the Haynes manual for guidance removing the engine (and associated lines, panels, front-end, etc.) but the ElsaWin definitely sounds worth a look.
Yeah, thanks for the info about the ElsaWin, I'll have to try to check that out. So far, I've used the Haynes manual for guidance removing the engine (and associated lines, panels, front-end, etc.) but the ElsaWin definitely sounds worth a look.
12-06-2014, 08:05 PM
#4
AudiWorld Newcomer
Join Date: Dec 2014
Location: San Diego
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
By "work", I mean bore, hone, and resurface (few thous) on the block and 3-angle valve job, press out/in valve guides/seals, and resurface of the head. All the part installs (including pistons, rings, rods, bearings, crank, cams, valves, valvesprings, rocker arms, and lash adjusters etc.) and full engine install will be done personally!
Yeah, thanks for the info about the ElsaWin, I'll have to try to check that out. So far, I've used the Haynes manual for guidance removing the engine (and associated lines, panels, front-end, etc.) but the ElsaWin definitely sounds worth a look.
Yeah, thanks for the info about the ElsaWin, I'll have to try to check that out. So far, I've used the Haynes manual for guidance removing the engine (and associated lines, panels, front-end, etc.) but the ElsaWin definitely sounds worth a look.
Thread
Thread Starter
Forum
Replies
Last Post
insomniacdm
A4 (B5 Platform) Discussion
3
06-29-2016 08:46 AM
quadrinary
Audi 90 / 80 / Coupe quattro / Cabriolet
6
07-04-2006 08:07 PM