Low compression plus visible cylinder scoring

Sorry for the long list of questions, I go to school in a smaller town with limited access to quality mechanics. I very much appreciate your help.


Background
Recently had the rear main seal replaced after it went bad and for about a week everything was fine. Then the car started misfiring and I took it back to the only local European Indy mechanic. He did a full workup and found low compression in cylinder two. He also looked down the cylinder with a scope and found a small to medium amount of scoring on the cylinder wall. His thought was that with the recent main seal leak and possible oil loss, the scoring most likely recently happened and is likely the cause of the low compression. For about $700.00 he could pull the head and make sure it’s not a bad valve causing the low compression, but he thought this was relatively unlikely as I had the timing chain replaced preventatively at around 65, 00 miles and I guess he doesn’t see many valves go bad on their own without timing chain issues. I also called VW to get their opinion. While they agreed the low compression could be from the scoring, they weren’t quite so convinced and recommended I bring it in to them to have the head pulled for about $1,400.

Q1: How do we feel about having the head pulled? Do we agree this is likely engine scoring considering the possible recent oil loss, or do we feel like it still might be worth pulling the head to see if it’s not a bad valve, piston ring, gasket, etc?

Q2: Would a leak down test be a reasonable alternative prior to pulling the head? I’ve read that the location of the air leak can help pinpoint where the loss of compression is coming from (ie. Air from the CV valve, oil filler cap hole, or dipstick tube suggests cylinder wall damage vs air from the intake or throttle body suggests an issue with an intake valve). I ran this by VW and they just kind of said “it’s better to pull the head”. Is it possible a leak down test might help us decide whether or not pulling the head might be worth the money?

Q3: assuming this is cylinder wall & piston scoring... Would replacing the scored piston with a new one provide any improvement? The Indy mechanic said he wouldn’t advise it but thought i’d double check here.


- If scoring is the issue I’d have to install a used engine for $5,500. The trade in value of the car in working condition is 3-4k (despite Carvana selling them for 12k). I just don’t think It’s worth doing on a 13 year old car that’s likely going to have more issues. What I am wondering now is about driving the vehicle in it’s current state of low compression. The internet says this is a no-go and to take your car to get fixed ASAP. Does this apply to me if the issue is with low compression from scoring and I don’t plan on replacing the engine? My mechanic said at this point there is nothing wrong with getting what remaining life is left out of the car. Again, I’ve read online that with one cylinder out, the car would begin to shake uncontrollable and be unsafe to drive. So far the car has been running incredibly smooth. You can definitely tell the rhythm of the idle is off, and there is a very noticeable yet quiet sputtering sound from the engine, but otherwise the idle is smooth and the acceleration is smooth and strong. Can a broke college student live with this for a year until he has enough saved up for another vehicle?

Q4: Do we agree with my mechanic that it’s safe to drive? Is there anything I could be damaging by driving it, and would this even matter considering the car essentially has zero value and I have no plans to put in a used motor?

Q5: Anything I should be aware of should I continue to drive it? I know I have to worry about unused gas making its way to the catalytic converter and damaging it. I asked my mechanic if we should disconnect the injector to prevent this but he said the car should do this automatically after it detects enough misfires (and from what I can tell this does seem to happen). Anything else?

Q6: Since the CEL is going to remain on, would purchasing and OBD2 scanner and pulling the codes weekly just to make sure other repairs can be addressed as they come up be a reasonable idea? Don’t want the permanent CEL to mask new (and potentially easily fixable) codes as the arise.

Q7: anything relevant that you think i’ve failed to address?