My guess would be screeching from a worn water pump, sometimes difficult to isolate with a stethoscope around moving parts and belts. I'd throw in some water pump lubricant additive to see if it goes away -it's not expensive and wouldn't hurt, just makes the coolant a little milky. I've continued to drive with lubricant for some time as long as it doesn't start leaking.
For rough running, based on recent work, I'd say incorrect timing belt installation is a distinct possibility. I'd re-check timing belt installation and also check the TDC mark and notch in the built guide for the crankshaft balancer using a probe in the #1 spark plug hole, carefully splitting the difference on either side of reaching the high point from opposite directions. You can temporarity re-install the timing cover to use the timing marks on it for accuracy, then check the belt timing mark on the crankshaft belt guide to see if it's correctly aligned.
As an AMM was just installed, I'd want to put it on the potential suspect list. If it was used then it definitely goes on the suspect list. Also if someone ever tried using spray AMM cleaner on it, not good for hot wire AMMs, then that makes it a higher suspect, trust me on the that one, learned the hard way. If you could try it another engine you'd soon know. Any LH2.4 engine would do, 1989-on 240/700/900.
--
Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now
|