thinfire

OK Guys, I have been on this forum at different times looking for answers for my 2002 RX300, we have only 112K on the ODO but haven’t come across this one or anyone else who has had this problem.
During a trip we experienced some roughness in the vehicle at highway speeds (barely) but pretty rough in drive at idle. We returned from our trip (6 hrs. each way) and took it to the dealer.
Diagnosis: Random misfire caused by a Seized Piston Ring causing low cylinder pressure on #2 cylinder (35lbs.), others checked out at 180lbs.
Remedy: rebuild engine at $6000.00
Question: are they just treating the symptom of a larger problem? The dealer said there was no “oil gelling”
I’m thinking that the problem could be worn valve guides, high oil consumption leading to carbon buildup.
They have offered to cover 25% of the repair as a goodwill gesture. Still a lot of money.
We did experience very low oil level on one occasion before this but no low oil light. Could the light be defective as well?
How would anyone out there pursue this?
Thanks to all in advance.

code58

That might be an accurate diagnosis, but I would want to know how they arrived at that. That would be unusual to say the least for the rings to seize on one cylinder and (obviously, at 180 lbs) NOT seize on the other 5. With the hard valves and guides that they have used since going to unleaded fuel 30 years ago, it's very unusual for there to be that kind of wear on valves or guides and though seals do go bad occasionally, they also don't give the problem they once did. I think I would be tempted to pull the plug on that cylinder and pour some Marvel Mystery Oil in and let it soak for a day or so. Then run some Auto RX in a new oil change and see if you can get the rings on that cylinder to free up, if in fact they ARE stuck. you don't have a lot to lose, those things aren't likely to hurt anything, could only help. Be sure and remove the excess MMO if you used that by spinning it over with the ign. disabled and a rag over the hole. Just sounds unusual to me. If it were my car, I'd want to take a look in that (and the other ) spark plug holes with a borescope to see what things actually look like.