Update: Replaced Manifold gaskets, no oil pressure

[97 silver 4.0]

I'm back to update after 2 months of trying to fix the problem of lost oil pressure after replacing my upper and lower manifold gaskets.
The problem being my engine had sludged up incredibly because antifreeze was leaking from the lower manifold gasket just enough to not be able to detect it in the oil by sight. It never showed on the dip stick and when I changed the oil I never saw any signs of antifreeze in it, however I drained it directly into the recycle pan. I should have known if it was leaking on the outside it was leaking on the inside but I did not know this would have created a big sludge problem.

Trying not to have to pull the engine to get to the pickup screen and oil pump
I did try to flush the engine with many, many oil changes, that is running the oil through, catching it and straining it, even with the manifold off. I also tried the soak it in kerosene treatment and also had enough pressure to idle the engine so I could run the kerosene through it but the sludge would not leave. Before I did all these oil flushes about 120 in all I carefully cleaned the top end and lifters with kerosene.

I found a mechanic who replaced the oil pump and screen for $650 which were both clogged and somehow was able to lift the engine enough to take off the oil pan without removing the engine.

I just got it back from the shop on Saturday and have run it about 120 miles so far. Oil pressure maintains 40-55psi running, idle at 20-10psi at warm idle, no lifter noise what so ever and I don't think I messed up the bearings and no leaks that I can detect. I also dropped the oil twice and found only a couple of real small pieces of dirt.

It was still running alittle rough and the CEL came back on with codes P0133/P0153, not the original P0171/P0174. Today I thought I should clean the MAF and intake connection because when I was doing all the oil flushes, some of the oil ran up into the intake through the vent hose which I should have disconnected when flowing so much oil through there and when I took it apart I found a shop rag behind the air filter blocking the air inlet, this should take care of the CEL trouble codes. Just another reason I don't like others working on my vehicles.

So anyway I haven't given up on my Ranger yet and thanks again for the helpful info I received from Rockledge, Fordboy and others.


from Rockledge, Fordboy and others