Hello all,

Long time Audi lover (and reader). While on vacation recently (over 1000 miles from home), I ran into a situation that I'm unable to troubleshoot on my own so I'm hopeful some of the great minds on here can provide some additional insight/suggestions...

I was driving down the highway at about 80 accelerating at fairly high boost (in manual mode, probably around 5k RPM) and then I heard a loud"pop" kind of like a gun shot... I looked down and saw my oil pressure light was on and my engine was making a loud noise, I figured I'd blown my turbo since I was still able to drive, just an immediate loss of boost (at least that was my initial suspicion). I drove the car a mile and a half to the nearest exit and pulled into a gas station right at the exit and had it towed to a local mechanic. While I was waiting for the tow truck, my dad suggested starting it up and driving it a couple hundred yards to see if I had oil pressure (trying to rule out some things before my car was taken) and the oil pressure light didn't trigger again and the engine wasn't loud at all (until I got to ~25-30mph for a few secs). At this point, my dad (who was on the phone with me) was pretty sure my Turbo was toast. I parked the car and waited for the tow truck.

The shop verified the turbo was toast and they also said my oil filter was FILTHY and made a guess that it hadn't been changed in quite some time. This part is distressing since I take my car to my mechanic like clockwork, every 8-10k miles (or before any long trip like this one) and have my oil changed and my tires rotated. He theorized that the filthy oil filter was starving my turbo of oil which caused it to fail.

I had them order a remanufactured turbo kit (I wanted something they could warranty) and it was installed earlier this week. Once the turbo was installed, they took it for a test drive and it was having issues (I forgot what he said, I think he said it went into limp mode) so he took the sub frame off to get at the oil dump and he found metal shavings in there (presumably from the turbo coming apart) so he cleaned it out and had his tech flush the system to get all remaining shavings out yesterday.

After test driving the car again after cleaning the system, it was still triggering the limp mode (I'm not a mechanic as you can see but between my dad and google, I have a pretty good idea of what's going on now). The shop said my engine needed to be replaced and I told them to get me some pricing on some salvaged engines which I should have the prices on Monday.

In the meantime, I spoke with my dad for a while and after going through everything that's transpired, his confidence level in the shop isn't very high since he would have approached this completely differently (my dad isn't a licensed mechanic but he's worked on cars all his life) and for the most part, I'm starting to feel like he may be on to something...

First question, how is it possible that a blown turbo could have damaged my engine? I've spent the last couple hours reading every story I could find on turbo failures and nearly all of them result in the engine surviving but some associated parts being replaced. Based on how the turbo interfaces with the rest of the engine, I don't see either (I may not be a mechanic but the mechanics/physics are pretty straight forward). The only thing that makes sense as that after I drove the car to the exit and drove it the extra couple hundred yards, I got bits of metal shrapnel in my motor which caused damage yet while I drove it the 200 yards, the oil pressure light didn't trigger so that makes me skeptical that the engine is in fact dead.

Second question, could another part near the shattered turbo be causing a misdiagnosis? My dad theorizes that it may be a sensor or other piece (intercooler, etc) that was damaged and is causing the car to go into limp mode (I haven't researched every reason it'll happen but I will after I finish this post).

Lastly, I'm in $3,000 so far, is this reasonable for this work? Purchase and install a re-man turbo and a thermostat, extra labor to take the sub frame apart (whatever it's called, the piece that's in the way of the turbo/oil dump), flush the system of oil, replace the oil pump (or something, was a $50 part he said) and put it back together) and of course add new oil.

Thoughts? I'm going to see the car on Monday and take pics of the oil filter and the damaged turbo in case I need to litigate against my mechanic back home. I also need to find out if there was oil sludge (there should be if the filter was that dirty, right?).

 

If the turbo blew and small pieces were sucked into the intake, there could be your problem.

I'm not sure how they can tell if your oil filter was "dirty". I've never seen a "clean" one after you run it for a while. If it's a cartridge type. they will usually collapse a bit when they are getting "dirty".

Also, another thing to think about. Some shops will talk up a story blaming the "other" mechanic hoping to get your business. Take their talk with a grain of salt. Engines blow all the time and it's no one's fault but the nature of the beast. Turbo cars even more so because of the ungodly RPMs that turbos turn and the additional heat generated by them.