Low Oil Warning???

[thatonemamabear]

So as a last ditch effort, I figured I'd come to folks who have an idea.

This all started early this morning on my way to school. The low oil pressure light came up and the dial bottomed out and then bounced to normal. My school was bout a mile out and it kept up with this pattern. The officer helped me check the oil, and he said it was fine. Just most likely the sensor went out.

On my way home, it completely bottomed out and the light came on. My service engine light popped up and started blinking at the same time. My speed started dropping drastically. When I parked, I tried starting it, but there was no noise what so ever.

I changed the oil about two weeks ago, and the fuel pump was replaced 6 months ago. Any clue what it could be? I love this car to death, and I really don't want to replace it.

 

[utilitytristin]

Is there a check engine light for any sensor faults? Not sure if the oil pressure sensor will trip a check engine light if it goes bad. If the oil is fine, it's likely a sensor that's bad or is going bad.

There's also a difference between low oil and low oil pressure.

Flashing check engine light means that there is a major fault and usually the car will limit it's power as well.

 

[BKennedy]

There is a difference between low oil level and low oil pressure. Is it the oil level or the oil pressure? If it's the oil level and you checked it, then it's most likely a sensor. If it's oil pressure, then that could be a failing oil pump, bad sensor, or both.

 

[Mbrooks420]

It could be a lot of things. If it’s a SOHC the oil pickup could be blocked by timing component bits. If it’s not been maintained the motor could be sludged up.

 

[Fix4Dirt]

So as a last ditch effort, I figured I'd come to folks who have an idea.

This all started early this morning on my way to school. The low oil pressure light came up and the dial bottomed out and then bounced to normal. My school was bout a mile out and it kept up with this pattern. The officer helped me check the oil, and he said it was fine. Just most likely the sensor went out.

On my way home, it completely bottomed out and the light came on. My service engine light popped up and started blinking at the same time. My speed started dropping drastically. When I parked, I tried starting it, but there was no noise what so ever.

I changed the oil about two weeks ago, and the fuel pump was replaced 6 months ago. Any clue what it could be? I love this car to death, and I really don't want to replace it.

welcome! if its a sohc sometimes the pickup can be clogged with timing bits if youve had rattle. if its low pressure stop driving and do more digging. if you can find an alt way to get to school

 

[Turdle]

Could be bad alternator and battery

 

[Mbrooks420]

It’s important to figure out if you do have a low oil pressure condition. If so you can’t drive it, and it may already have been damaged.

 

[LMHmedchem]

It’s important to figure out if you do have a low oil pressure condition. If so you can’t drive it, and it may already have been damaged.

Was there any temperature spike when you were driving and the check engine light came on? If your oil flow was blocked or the oil pump quit (which it could even though it's new if the replacement wasn't a quality part), I would expect the engine temperature to go up. It's hard to imagine that your oil flow went low enough to trigger a check engine light without the temperature going up significantly but perhaps you just didn't notice with the other things going on.

Like Mbrooks said, you can't drive this until you figure out what the issue is. I wouldn't even try to start it. I think you need to get hooked up to a computer to see if there are any codes that were registered with the check engine light.

It wouldn't hurt to check the battery voltage and check the belt to make sure it's tight. A badly worn belt or loose tensioner can cause the battery to drain and also cause a loss of oil pressure. I'm not sure if that would cause the reduction in speed or not.

Hopefully you didn't damage it by driving with no oil pressure but first you need to figure out why it won't start and go from there. If your battery voltage is low then you can try jumping it or having your battery charged. Don't start it, just see if you can get the engine to turn over. If it turns over then it's much less likely that you did engine damage.

What does your oil look like? Since you just changed it, it should still be relatively clear.

If this is the v8 then a common cause of the reading from the oil pressure sensor dropping out is this issue,

Have a 4.6L? Here's a problem I bet you all have...

One of the wires affected by this issue is the connector to the oil pressure sensor. Another of the wires is the connector to the starter, so in theory, this could explain both problems. The wire to the starter is huge so I think it's unlikely that it has worn through but I guess it's possible, or that it has worn enough to short, or something like that. You can check this by looking for wear on the the large wire harness that runs right under the oil filter drip tray. If this is a v6 then this issue doesn't apply.

LMHmedchem

 

[Mbrooks420]

By the time a low oil condition heated the motor to a degree visible on the gauge the motor would be smoked.

It’d also sound clattery, and generally unhealthy.

 

[LMHmedchem]

By the time a low oil condition heated the motor to a degree visible on the gauge the motor would be smoked.

The one time I lost an oil pump I first heard a loud clicking sound that I assumed was the tappets. The sound was followed by the engine temp light coming on and then the oil light. That was back in the days when you had separate warning lights for everything instead of the idiot check engine light. In that case I got a temperature warning before the oil warning, but not before the sound. That was a much simpler engine with heavier oil.

It’d also sound clattery, and generally unhealthy.

Yes, like my situation, I would expect allot of noise from the engine if there was no, or very limited, oil circulation. Since sounds like this were not reported I am hoping that poor oil circulation was not the case. Perhaps this is just wishful thinking on my part on behalf of the owner. I do hope that the engine isn't bricked.

Do you think that an electrical issue such as low alternator voltage would cause the engine to lose power as was reported? I don't know of a direct mechanism that would cause that but that doesn't mean there isn't one. Perhaps the PCM does this when it detects low voltage.

LMHmedchem

 

[Mbrooks420]

Low voltage could cause a lot of issues. If there was no charging and it went flat the coils wouldn’t be able to fire the plugs, or the injectors. Blinking CEL generally means misfire.

 

[thatonemamabear]

The one time I lost an oil pump I first heard a loud clicking sound that I assumed was the tappets. The sound was followed by the engine temp light coming on and then the oil light. That was back in the days when you had separate warning lights for everything instead of the idiot check engine light. In that case I got a temperature warning before the oil warning, but not before the sound. That was a much simpler engine with heavier oil.


Yes, like my situation, I would expect allot of noise from the engine if there was no, or very limited, oil circulation. Since sounds like this were not reported I am hoping that poor oil circulation was not the case. Perhaps this is just wishful thinking on my part on behalf of the owner. I do hope that the engine isn't bricked.

Do you think that an electrical issue such as low alternator voltage would cause the engine to lose power as was reported? I don't know of a direct mechanism that would cause that but that doesn't mean there isn't one. Perhaps the PCM does this when it detects low voltage.

LMHmedchem

There was no noise. It ran quiet and smooth which isn't like it. Mechanic looked at it, and said the engines seized.

 

[Mbrooks420]

That’s easy to verify. Just try and turn the crank with a wrench.

Does sound like you drove it without pressure, which would kill a motor in very short order.

 

[LMHmedchem]

There was no noise. It ran quiet and smooth which isn't like it. Mechanic looked at it, and said the engines seized.

I have a bit of a hard time believing that the engine ran out of oil and seized up without making any sounds whatsoever. To me, the list of symptoms sounds more electrical but that is only a guess from a distance.

Unless you have good reason to really, really, trust the mechanic then I would look into this further.

Did you test the battery?
Did you check the belt system?

I would check the battery with a DMM or take it to an auto parts store and have it tested. If the battery is well charged and it won't turn over at all then it is more likely that you damaged the engine. If the battery is dead, then get it charged and see if you can get the motor to turn over. If the belt is loose then that would explain all of the symptoms you described. You still need to charge the battery but it's up in the air if the engine is damaged since the loose belt will cause a drop in oil pressure.

As MBrooks420 said, look up a video on how to crank the engine by hand and see if you can do it. A large engine like this has allot of compression, so if you remove the spark plugs first, you should be able to more easily check if the crankshaft will still move or not. It's worth an afternoon of your time before you spend $3000+ on a rebuilt engine or just junk it.

Many years ago I had a friend who had an engine (Cadillac) that overheated and then wouldn't start. He took it to a shop where the mechanic showed him that he could not turn the crankshaft at all with a breaker bar. He said that the engine was seized and had to be replaced. My friend wasn't sure that he wanted to put that much money into it and so just had it towed home. Another friend told him that a large v8 like that has so much compression that it might not be possible to turn by hand even if the engine was fine. I don't know if that is true or not but that is what he said, At any rate, he removed the plugs and the crankshaft turned fairly easily. I don't remember what needed to be replaced but it cost less than $100 to get it going again. My friend ended up giving the guy $1000 for saving him from buying a new engine for no reason. I don't know if the engine wouldn't turn because of the compression or if the mechanic was faking that it wouldn't turn, but the engine definitely didn't need to be replaced.

It's sad that there are numerous mechanics who are dishonest and take advantage of the fact that the owner generally has no direct way of verifying what the mechanic says the issue is. I remember standing in a tire and general maintenance chain location listening to a mechanic tell me that coolant had got on the "timing belt" of my Gen 1 explorer and that the belt would be damaged by the coolant. He said he would replace the belt for $650 and it would take about an hour. That conversation ended up involving the manager and then the Police because they gave me my truck back without tightening the lug nuts on my tires. I have no idea about the mechanic who looked at your truck and it's certainly possible that the engine is gone but I would do some checking on my own before giving up on it or buying a new engine.

LMHmedchem

 

[thatonemamabear]

Was there any temperature spike when you were driving and the check engine light came on? If your oil flow was blocked or the oil pump quit (which it could even though it's new if the replacement wasn't a quality part), I would expect the engine temperature to go up. It's hard to imagine that your oil flow went low enough to trigger a check engine light without the temperature going up significantly but perhaps you just didn't notice with the other things going on.

Like Mbrooks said, you can't drive this until you figure out what the issue is. I wouldn't even try to start it. I think you need to get hooked up to a computer to see if there are any codes that were registered with the check engine light.

It wouldn't hurt to check the battery voltage and check the belt to make sure it's tight. A badly worn belt or loose tensioner can cause the battery to drain and also cause a loss of oil pressure. I'm not sure if that would cause the reduction in speed or not.

Hopefully you didn't damage it by driving with no oil pressure but first you need to figure out why it won't start and go from there. If your battery voltage is low then you can try jumping it or having your battery charged. Don't start it, just see if you can get the engine to turn over. If it turns over then it's much less likely that you did engine damage.

What does your oil look like? Since you just changed it, it should still be relatively clear.

If this is the v8 then a common cause of the reading from the oil pressure sensor dropping out is this issue,

Have a 4.6L? Here's a problem I bet you all have...

One of the wires affected by this issue is the connector to the oil pressure sensor. Another of the wires is the connector to the starter, so in theory, this could explain both problems. The wire to the starter is huge so I think it's unlikely that it has worn through but I guess it's possible, or that it has worn enough to short, or something like that. You can check this by looking for wear on the the large wire harness that runs right under the oil filter drip tray. If this is a v6 then this issue doesn't apply.

LMHmedchem

So been a year, but it was the oil pump giving out and I killed the engine. But since you spent a minute typing this, we're replacing the engine so the old girl will live on