E84A 6A12tt Missfire - Suspected lifter failure

Hello VR4 family,
I will start of with saying I do not often post in forums so I do apologize if that shows.
I've owned my 95 VR4 E84A 6A12tt for roughly 8 years now and its been an incredible car. High maintenance for sure but that's the sacrifice you make when you get addicted to the vr4 spirit. I do all the work myself since otherwise it would leave me broke. Oil changes every 5000km, air filter changes, leads and spark plugs and coils all have been replaced several times :D and again now done about 100'000ks since purchase motor now at 261'000 which is of course a lot.

The problem:
Car currently has a misfire with high pitch ticking. Lifter tick, but not normal lifter tick, it sounds louder than usual.
It appears to be coming from the top of the engine. The motor starts relatively fine but it struggles through the RPM considerably.

So far I have replaced:
*Leads *Spark Plugs *coil packs have been checked also
* Oil change, oil filter change - no signs of bearing or other engine damage.

I suspect at this stage that its a collapsed lifter (missfire & loud tick indicate this) or it is the oil pump that has given up. I don't think it is the oil pump because the oil sensor is not lighting up. No error codes light up at all which is kind of the issue.

Anyways, I was going to get the car diagnosed to see if there are errors showing in the system (OBD1).

I know I can take the engine apart again for the 5x time and take the valve covers off and check the lifters and valve train but I am going to wait until I get it diagnosed before taking it apart again so it can run.

Does anyone have any experience in this? I have a second straight replacement motor (6A12tt) sitting in the garage for a couple of years now and am wondering if its time to replace the whole motor rather than doing all the lifter replacement work etc?

Any ideas would be appreciated all though I know its a long shot.

Thanks!

Ps: I will share a video very soon.

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