Low oil pressure, where to start?

[jimstolz76]

...continued from the other thread...
http://www.aveoforum.com/forum/f108/...er-hose-11133/

So I need to go back to basics. Here is what I did (we thought we were going to pull the entire intake manifold off; ended up not having to go that far but I had already started removing parts) --

- took air cleaner intake hose (and attached hoses/wiring harnesses) off
- took hoses off throttle body, unbolted and removed
- took hoses off PCV valve and hose from reservoir tank to throttle body
- unbolted metal piece that goes over fuel injectors
- loosened fuel injector bolts and fuel rail
- removed heater hose going to heater core, replaced with new one
- PCV valve broke in half while moving another hose; threads were stuck in valve cover
- pulled valve cover off
- laid a towel over the entire open engine
- stuck a 1/2" drill bit into the threads, turned it slightly forward
- jammed a knife (Gerber multi-tool) into the plastic and slowly unscrewed it out.
- installed new PCV valve, reattached all loose hoses and wiring harnesses

Car started with louder than usual valve tapping. Oil light started flickering. Eventually it stayed on. Let it sit, checked the oil level, tried it again, same thing. Let it sit a while, tried it again, this time after a couple minutes the tapping got a little bit less. Decided to try driving it a little. Light flickered, went out, came on, went out, stayed out. Decided to try to take it on the highway and while on the on ramp it started sounding really bad. Idle sounded like worse than usual valve tapping, but driving it sounded awful and made some horrible "I've got no oil in me!" noises. Stopped, pulled the oil filler cap and a little white smoke was billowing around inside. Dumped 1/2 quart of oil in, hoping it would slosh around long enough to just go right to the next exit and dump the car at a friend's house. Made it there and got a ride home.

I REALLY need to know what could cause the oil to not be pulled up into the top of the engine. I can't imagine this is a coincidental failure of the oil pump or something like that. I had the engine open and MUST have done something wrong.

I just stopped by to look for the hose that was pictured in the other thread. While there I started the car for about 2 seconds and it started right up (and had the usual valve tapping from the other day). I was really scared that I would find that the engine had seized up after the stupid beating I put it through last night..

We are going to tear into the car this weekend. Unfortunately neither of us know what to look for. My friend is much more experienced with internal engine work than me (about a 100%:0% ratio... LOL) and he's not sure what to look for. He just says "There is something we're not seeing. We just have to find what it is."

Any help is GREATLY appreciated. This is my wife's car, and until I get it fixed we have to borrow 2 other cars from other people just to get her to work and school...

Thanks guys!

[petrified.rabbit]

did you take the towel out of the engine? have all the pieces of the oil gaskets, and pvc valve?

if the engine is making noises, then its not just the sensor going bad. Now that i need to read two threads, did you answer me that it did not over heat?

based on where you were working, there is no real reason for it. did any coolant get in the oil? if the light is flickering then its getting pressure some of the time, does that correlate with the noise making?

[jimstolz76]

I started another thread so it would be easier for someone to find answers in the future... my old thread kinda went off on a tangent...

No, it didn't overheat. I didn't even know the heater hose broke until I stopped driving and saw thick white steam coming out from under the hood. The temp gauge was pegged at 195 (or whatever normal is...it hadn't budged...must've caught it just in time).

We have all of the PCV valve, yes the towel was taken out of the engine... I'd be surprised if we dropped anything into the engine, but I certainly can't rule it out at this point.

If something was dropped into the engine, where do we start looking? What is it that could have gotten blocked? There is a fair amount of sludgy mess in the engine, so it's also possible some of that got lodged somewhere. I could take the valve cover off again but wouldn't know what to look for.

[petrified.rabbit]

well oil pressure is controlled by the oil pump, even the sensor is in the bottom side of the engine..

did you jack it up using the oil pan when you tried getting under it?

the only thing i can figure, is the oil pick up has something clogging it.. its in the oil pan. dropping the oil pan is just like removing the valve cover, just upside down. If the pick up is partially blocked, or consuming sludge, it will drop your pressure. Valves are the first thing to make noise, if that was the what is making the noise, and it been around for a while, then this has been a building problem.. but fixing the obstruction should cure it, since there is enough pressure for the light to flicker..

[jimstolz76]

Question. There's supposed to be a heat shield on the flex pipe. Mine is missing. Did it face up to protect the oil pan? I opened the drain plug and nothing came out. I had to stab it open with a screwdriver to clean put the gunk. I'm no more than 5k since the last oil change. Maybe the exhaust is baking it? Neither of us has ever seen anything like this before.

[petrified.rabbit]

i'm not sure about the heat shield, but if you had to poke at the oil to get it out you better drop the pan, it sounds like plastic melted in there. It would cool and harden in the bottom of the pan.. any of the baffles or anything around the cams distorted? and i'm not sure but your engine might also have a plastic baffle for the oil pickup.. amongst other things.

i do doubt the exhaust is hotter than the combustion chamber though,so i dont think it would "bake" the oil..

[jimstolz76]

Holy crap. Got the oil pan off. The oil pickup nozzle was completely clogged. It looked like a pile of dirt, but upside down. Gonna try to get a pic.

[Avezoh]

The sludgy oil is an indication of the problem. Sludge doesn't flow. Sludgy oil is indicative of oil breakdown. If the oil is the factory recommended type and it's been changed at regular recommended intervals for the type of driving your wife does( if primarily short trips it needs changing more often than the recommended average interval ) then some other reason for oil breakdown exists. Heat is one primary cause. The leaking hose and white smoke are pretty good indicators of heat related issues going on.
The point is there's a cause and effect situation here. It's critical you and your buddy find the cause, otherwise you waste work and replace parts without finding the cause for the current situation. Dropping the pan was right on the money. Checking the sensor and wiring at the same time is necessary too. I'd replace the heat shield you mentioned if for no other reason than there's probably wiring nearby that can be affected by the heat, and possibly secondary heating of oil in the pan if the flex pipe runs close to it. Engineers don't specify parts that aren't necessary. That shield is important. Check the rest off the cooling system as well including the fan.
The source of the situation , as I mentioned earlier, and others have, is the key.

Steve

[jimstolz76]

Well I'm back home, and drove the Aveo here. The oil pan was COATED with 1/2" of sludge at the bottom. No exaggeration. The pickup nozzle was covered in a dome of crap. We think it may have even been sitting IN the sludge - that's how deep it was. We took it to another guy's house who has a garage and a nice parts cleaner and even he had never seen anything like it.

So it's back up and running, albeit with some new engine noises it didn't make before... argh. Idle sounds almost the same as before, but there is a very pronounced tapping at around 2300 RPMs and also sometimes during deceleration when the engine is under compression (probably using the wrong terminology). Very pronounced. Seems to run great, though. I filled it with Castrol GTX high mileage 10W30. (abt 85,000 miles).

At this point I just want the car to last another six months.

Thanks for all the feedback!