Lost compression to left left bank Options

[Willisbegood]

So everything was fine up until a few days ago when I noticed I was having a bit of a problem climbing RPMs when I got on the highway. My initial thought was that my fuel filter was plugged up so I changed it out and that didn’t fix it. I thought maybe because I ran an octane booster in it with supreme fuel that it may have just been running too rich. But it won’t stay running at idle. If I give it gas it will stay running but as soon as I let off it dies out and won’t stay running on its own. I figured it’s cause it was rich fuel so I added regular unleaded to bring the octane down but nothing changed. I then got curious and did a compression test and sure enough the left bank only holds 60lbs. (1&2) cylinders. Cylinder 3&4 hold 115 lbs. does this mean that the engine blew or a gasket blew? Do I need to get a new motor? Any and all input would be greatly appreciated guys thanks!

[Superhawk996]

Tough to call but based on symptoms of both 1&2 being so low. I'd guess you've lost torque on the cylinder head studs. Is there any excessive oil under the engine on the #1/#2 side?

I had a similar thing happen on a Type 1 VW bug engine long ago.

Have a leakdown test done or buy a leakdown gauge (~$100). With a leak down test you'll be able to tell where the leakage is.

Typically goes to 1 of 3 places. In your case you may have a #4.

1) Into the intake
2) Into the exhuast
3) Into the case

4) In your case, it may exit the cylinder between the head and the cylinder.

Plan on dropping the engine to fix any of the possible root causes.