We have a 2000 Toryota Sienna with about 130,000 miles on it. About a year ago we had a huge sludge problem that cost a lot to get fixed. Since then we have been dilligent about quality oil and changes. The oil light came on the other day and we realized the oil line was clogged completely with sludge and the engine was running with no oil getting to it–metal on metal. Our mechanic says time for a new engine or new car. It has been decloged, cleaned up and runs fine for now, but my husband and I are trying to decide the best route. He is leaning towards engine replacement (an engine with 35K) and I just want a reliable car and am uncetain if engine replacement (with a 2000 Sienna engine) will give us the reliability I am after or if we are better off trading this car in before it belongs in the junk yard. Thank for reading 
My first post…lol
Buy the new car and this time be diligent with the maintenance. Your vehicle choices in terms of reliabilty has expanded over the past few years, but I still would recommend a Toyota.
You just need to follow the maintenance schedule in your next vehicle. The fact that sludge killed your Sienna is all on you. You need to change the oil according to schedule. It is so much cheaper and easier than buying a new car.
You say it has been de-clogged, cleaned up, and runs fine for now. What is the problem? Run it until it dies–that is the least expensive transportation solution. From now on, change the oil every 3000 miles to avoid the same problem.
Or are you looking for a reason to get a newer vehicle?
I too wonder about the bit of information that says the car runs fine now. I also wonder about the statement that you spent money getting the sludge problem fixed but that it came back. In any case, alot depends on the condition of the rest of the car (which you don’t say any thing about) This leaves me to believe the rest of the car was a neglected as the engine, can you clear this up?
Based on what little I know about your situation (and what I suspect) I say change cars all together and do better with maintence on the newer car.
Toyota engines of this vintage are highly prone to sludging. Slightly lax or even regular oil change habits trashed the motors due to a poorly designed PCV system overheating interior of engine leaving deposits.
Toyota owned up to it however they extended the warranty to 8 years so the poster is out.
I am well aware of the Toyota sludge situation.
If the engine was running metal-on-metal it would likely have seized. If it is running fine now, just run it until it dies. Change that oil often and avoid short trips, though!