Hello,
Just bought my first 4Runner, a 1998 4 Cylinder 5 speed with 220k miles from the original owner. Got a deal on it (at least I think so..) because it has what the seller described as "top end noise."
Here's what I'm experiencing:
When first started, runs pretty smoothly with a subtle *clack clack clack*. I hoped when I test drive that this was valve noise, knowing I can adjust those myself.
However, once the engine is good and warm - maybe 10-15 minutes down the road, this noise gets louder. When I pull over and listen under the hood, the noise sounds more like a knock..

The second issue that seems to go hand in hand with the noise is lack of power. I have read enough around this forum to know not to expect much pull out of the little 2.7 4 cylinder, but there definitely seems to be an issue. In first gear it took everything it had to get up the small hill in my driveway. The Honda Civic climbs that just fine. On the highway I have to downshift into 3rd to make it up gentle grades doing 55 mph.

So far I've been told by friends it might be (please no) rod knock, a timing issue with spark not advancing, or an oil pump causing other problems.

Doubting it's anything catastrophic bc of good maintenance records and relatively low mileage.

Any similar experiences? Ideas for diagnostics I can run?