1989 Dakota V6 No Oil Pressure

[C_alexander]

I have a 1989 2wd dodge dakota with athe 3.9l v6. I had been having some problems with the oil pressure dropping occasionally (no real pattern) and the oil light coming on. This was usually cured by revving the engine. Recently I lost ALL oil pressure while driving around town so I took it into the dealer. They replaces the oil sending unit and I had great oil pressure for a few days until I was driving far from home again and then I suddenly lost all pressure again. I thought it was the sensor again so I continued to drive home, but the more I drove the louder the engine got. My car sounded like a diesel engine by the time I got home (16 miles away).
At this point I call the dealership and they say well it might be the oil screen, and that my engine is now probably damaged beyond repair due to the noises it wsas making. They won't work on it now. So I took off the valve cover gaskets to see the damage. They are BLACk with sludge. I clean them up, clean up the oil returns, put it all back together, drain the oil ( it was changed 1,000 miles ago but was black and chunky...most likely due to the mess udner the valve covers). I flush the system out with 2 quarts of oil to make sure I got the gunk out, then refill it with 2 bottles of engine flush, a bottle of transmission fluid and 2qts oil (mechanic told me ATF was great for cleaning out oil system....although you are suppose to fill your car up with oil anbd replace 1 qt or oil with 1 qt of automatic Transmission Fluid every oil change) Ok so I let this mix soak for hours, then went to start it up and still no oil pressure. Granted the mix was rather thin, but I shoud have got something right? I plan on draining this mix after letting it soak a little more ( to clean the oil screen) then draining and refilling it with only 10w-30 oil and restarting it.

My question is this....is there something I am missing here? Has anyone had problems with the oil sending units? I can't believe this new one is already out. I also can't tell if the engine is pumping oil or not. The engine is a little louder then I remember it to be, I think in part to the thin flush mix I am running in it. If the oil pump was out there would be a distinctive noise from the oil pan at there is not.
What does an oil pressure switch do and does this truck have one? Would that maybe cause this?

Please help!!! AGH! haha

If I can't fix this I am walking and I live inteh middle of no where. haha

[SteveB05]

Well the oil pressure switch is working... it turned on the lite when your pressure dropped. That is what it does.

If your engine was making more noise the longer you drove it with the lite on, you really have an issue. The bottom end is not nessesarily the first audible alert...its usually the top end that makes noise first.

Go get a cheap mechanical oil pressure gauge...fill it up with regular oil and see what you get. My guess is a need to buy some really good shoes.

[C_alexander]

I am taking it to a mechanic to get the oil pump replaced, the rear main seal replaced, and the oil screen cleaned along with the oil pan. Found a guy that'd do it for under $400.

The engine was well soaked with Slick 50 and upon taking off the vavle cover gaskets, everything looks alright. I cleaned it up really good, cleaned out the oil returns and got rid of all the thick black oil on the rockers and such.

I flushed it out several times with engine flush and transmission fluid to get any sludge out of the system. It WAS very dirty.

After all that, still no oil pressure at all...my vote is oil pump. Nothing else left.

[theFREAKnasty82]

Hope you don't have clogged oil galleys. If you do, you'll have to pull the motor out just to clean them out. No motor flush in the world can clean sludge built up in thin oil galley passages.

[C_alexander]

I had the truck repaired today at a local personal garage. I had the oil pan cleaned out, the oil pump replaced, the oil scren cleaned and the rear main seal replaced..all for a VERY good price. The truck is running VERY well and quiet, so no damage to the rockers, main bearings or anything. Thanks for all the help and input though. Perhaps this can help someone else in the future