A Total Novice's Start with a 1984 4x4 SR5 -- Advice Thread

[Petros]

is your valve clearance correct? check the fuel pump, they can get noisy too.

might also be an exhaust leak, it can sound like a knock if it is up close to head or exhaust manifold. Check by putting your hands around the manifold at various places, do not touch it, hold them back, everything is hot. You will feel the "puff, puff, puff" of warm exhaust where there is a leak.

You can also try and find it with either one of those auto stethoscope (only about $20, very useful tool), or just use a long screw driver or other similar solid steel rod. YOu place the tip on various parts of the engine, and press the other end against your ear. local noise will transmit up the shaft and you will "hear" it as it transmits into your head.

If it is non-localized and deep in the engine it might be piston slap, or too much rod bearing clearnace. Adding STP or similar oil thickening agent will take care of it until you can rebuild or replace the engine. This happens if dirty motor oil is not change often enough, the dirty oil slowly wears away the cylinders or crank bearings like fine sanding grit.

[xirdneh]

Sounds like valve clearance adjustment (done with hot engine) needed and,/or a sticking valve