HELP - Low oil pressure

[psteng19]

1994 Nissan Quest 3.0L V6 4 Speed Auto 110K miles

The dash lights come on, most notably the low oil pressure light.
When checking the dipstick, it reads on the low end.
I do not see spots of oil under the car after parked.
I do not see blue smoke coming out the exhaust.

This has happened 3 times in the past 5 months.
Each time I add oil (10W-30) until normal levels.
Problem goes away for a few weeks.

Pretty certain that the low oil level is causing the low oil pressure.
Now what's causing the oil to disappear?

 

[Pepsi90919]

it's being burned.

and stop letting the oil light come on.

 

[amdskip]

What is it running as far as temps are concerned?

Could very well be a cracked head or bad head gasket. Does your oil have anti freeze mixed in it?

 

[Eli]

Uh....

You do realize that if your waiting until the oil light comes on to put more oil in it, you are severely damaging your engine, even before the light comes on?

Think of your our oil as a giant heatsink(In addition to its lubricating qualities). If you have less than full volume of oil, you are hindering your oils ability to cool your engine.

Anyway.. Is your coolant level OK? Do you notice oil in your coolant, or coolant in your oil when you change it?

You do change your oil... right?

 

[psteng19]

Well, I don't drive it, my mom does.

Temps are normal, except once when the water pump went, it got pretty hot.
That was maybe a year ago.

Oil changes at 4k intervals at mechanic, who hasn't mentioned anything about coolant in oil.

I will check the coolant for oil.
How does the coolant and oil mix?

 

[Eli]

Originally posted by: psteng19
Well, I don't drive it, my mom does.

Temps are normal, except once when the water pump went, it got pretty hot.
That was maybe a year ago.

Oil changes at 4k intervals at mechanic, who hasn't mentioned anything about coolant in oil.

I will check the coolant for oil.
How does the coolant and oil mix?

It doesen't, really.

Look for nasty sh!t on the underside of the radiator cap.. and just generally oily nasty coolant.

The temperature gauge is not going to tell you if your engines oil and bottom end is overheating. It measures the coolant temperature.

That overheat could very well be the source of your problems. My bet is cracked cylinder head, or worn valve guides, although you would probably see at least a bit of smoke if it was burning it.

If it goes through nearly all of its oil within the 4k interval, something is seriously wrong. Are you sure there is no blue smoke out the exhaust? It won't be noticable when idling, you'll have to have someone rev it...

 

[iamwiz82]

If your oil is only low, and not absent from the dipstick, you have more wrong than a quart of oil missing.

 

[psteng19]

Originally posted by: Eli

Originally posted by: psteng19
Well, I don't drive it, my mom does.

Temps are normal, except once when the water pump went, it got pretty hot.
That was maybe a year ago.

Oil changes at 4k intervals at mechanic, who hasn't mentioned anything about coolant in oil.

I will check the coolant for oil.
How does the coolant and oil mix?

It doesen't, really.

Look for nasty sh!t on the underside of the radiator cap.. and just generally oily nasty coolant.

The temperature gauge is not going to tell you if your engines oil and bottom end is overheating. It measures the coolant temperature.

That overheat could very well be the source of your problems. My bet is cracked cylinder head, or worn valve guides, although you would probably see at least a bit of smoke if it was burning it.

If it goes through nearly all of its oil within the 4k interval, something is seriously wrong. Are you sure there is no blue smoke out the exhaust? It won't be noticable when idling, you'll have to have someone rev it...

Yeah, that's how I checked.
I had the car idle a few minutes, and then revved it slightly, maybe 2.5k, for only a few seconds and saw nothing.
I could try that again.

If something's wrong with the internals of the engine, such as the valves or cylinder as you suggest, how much will repairs be?
It's probably not worth to fix it, right?

 

[iamwiz82]

Do you have an oil pressure gauge? Get a mechanical one and check it. Dont just trust an idiot light.

 

[Eli]

Originally posted by: iamwiz82
Do you have an oil pressure gauge? Get a mechanical one and check it. Dont just trust an idiot light.

Yeah, I was going to mention that too... but it does sound like he has a genuine oil-level related problem.

I wish Roger were around, I'm not really very good at diagnosing specifics..

 

[psteng19]

Originally posted by: Eli

Originally posted by: iamwiz82
Do you have an oil pressure gauge? Get a mechanical one and check it. Dont just trust an idiot light.

Yeah, I was going to mention that too... but it does sound like he has a genuine oil-level related problem.

I wish Roger were around, I'm not really very good at diagnosing specifics..

Aren't you the ATOT oil expert?
I'm not too handy when it comes to working on a car. I'll get a mechanic to look at it.

How much do you think repairs will be, if the problem is burning oil due to cylinder/gaskets?

 

[iamwiz82]

I think most oil pressure lights go off at 5psi or so. That means that being only one quart low could not set off the light unless there was another issue.

 

[Eli]

Originally posted by: psteng19

Originally posted by: Eli

Originally posted by: iamwiz82
Do you have an oil pressure gauge? Get a mechanical one and check it. Dont just trust an idiot light.

Yeah, I was going to mention that too... but it does sound like he has a genuine oil-level related problem.

I wish Roger were around, I'm not really very good at diagnosing specifics..

Aren't you the ATOT oil expert?
I'm not too handy when it comes to working on a car. I'll get a mechanic to look at it.

How much do you think repairs will be, if the problem is burning oil due to cylinder/gaskets?

If you can't see any blue smoke when you step on the gas(go ahead and stomp it to the floor and let off, when you try), then I doubt the engine is physically worn out. It shouldn't be after only 118k.

You need to figure out where the oil is going, and you need to make sure you keep it full. Adding oil when the light comes on is absolutely unacceptable.

If the cylinder head cracked as a result of the overheat, it will be fairly expensive to fix, but unless the car is in otherwise aweful condition, it should be worth it.

 

[Evadman]

Originally posted by: iamwiz82
I think most oil pressure lights go off at 5psi or so. That means that being only one quart low could not set off the light unless there was another issue.

The sender is loacted in the front of the block. Maybe psteng19's mom drives like a bat out of hell?

Either way, time to bust that pan gasket. as iamwiz82 says, it takes more than being a little low to make the light come on. The pickup may have worked its way loose and rotated enough so that being a little low uncovers the pickup. Hell, it could be about a dozen things.

 

[Scarpozzi]

SELL SELL SELL!!!! And buy a Scion while they're cheap.