I have a 740T w/ over 206K miles. Within the past 50K I have installed new head, piston rings & rod bearings, valves, turbo unit, idle speed motor, fuel pressure regulator, air mass meters, oxygen sensor, power stage boost, main fuel pump & pre-pump & relays, engine wiring harness, & a whole bunch of other stuff. In other words, I have spent over the past 5 years nearly $10K on it. I love my Volvo but I can no longer afford service shop prices & have started to do work myself. I am pretty mechanically inclined & can follow (some) directions but I lack the troubleshooting skills.

My problem now is: Blew my dipstick out last week. Oil everywhere! Also suddenly had lack of power & horrible idle & rough running under load whcih smooths out has it starts moving along. Decided to focus on the pressure first figuring the rough running was something fouled. Cleaned out the pcv system found the fittings clogged. Still blew out the dipstick. Put the o-ring on the stick, no longer blew out there but now blows under the oil filler cap. Put on new gasket under cap, still blows there and keeps on blowing off the small hose (part of pcv system) that goes to the intake manifold at the Y-plastic fitting. Obviously still have excess pressure. Now my big blunder, pulled the breather box to clean (before reading the warning) and out came the hose that goes into the oil pan. The end looked broken & jagged. Went back in though! I then flushed the engine and replaced oil & new filter. No evidence of water in oil or fuel in oil(dont know what that looks like). Started to work on the rough running. Replaced plugs, wires, distributor & rotor, no difference. Checked if injector seals were leaking but no difference in idle or fluid being sucked in when carb cleaner sprayed into each injector. I am stumped.

My plan is to first pull the oil pan and replace the broken plastic tube making sure it is clipped into place. Next what do I do? I am worried I have a broken ring. But I did have the rings, and bearings replaced about 5oK ago. And did a valve job with new head about 25K ago when it overheated and cracked the head. Could I have a head gasket leak (but no radiator fluid getting by). My car overheated 2 months ago & I put in a new water pump and it did get awfulliy hot but I kept it full with coolant (stopping every 20 miles) until I got home to fix. My exhaust is clear no black or white smoke visible and it passed smog just 2 weeks ago with flying colors which doesnt make sense if I had a ring leaking unless it broke suddenly? Could my intake manifolds be leaking or is there a vacuum leak possible that isnt part of the pcv system. My pcv valves were clogged possible being the original cause, but are my new running problems a result or a cause. What else should I check? Help!