The way to tell if the bottom end needs rebuilt is to: Get an accurate mechanical OP guage. Then run the engine full throttle for 20sec (at highway speeds)then let completely off and watch the guage. When you let off the crank will center its self in the main bearing because there is no longer a down load on the crank. When the crank is centered, less pressure escapes from around the main bearing. If the OP increases more than about 2-3 psi then the main bearings are getting loose.
quote:What oil filters are you using? What oil weight are you using?
Originally posted by 55: The Celica is an 88, with 208000 kms. The wagon is a 90, with 249000 kms. I notice when I start the Celica I hear some clatter for a second or so after I start it, then the motor tends to be a bit noisy for the first minute or so when I'm driving it. The 3300 in the wagon doesn't make a sound, and isn't noisy during the first few minutes when I start driving it like the Celica is.
quote:Jon, unless it's a mechanical gauge (and few are), the power to the gauge is shut off, and the residual oil pressure has nothing to do with the fall of the needle. Also, with no accumulator in the system, as soon as the pump stops turning, pressure should be zero. I beleive that most electrical gauges fitted to cars are so heavily damped that the slow rise/fall is due to gauge design, and to stop people worrying about spikes/dips.
Originally posted by JonS: I've heard that when you shut down an engine, the pressure on the gauge show go down really slow. If it goes down fast, this mean worn bearings.