Bouncing oil press.

[Viper Command]

'97 3.0 auto w/ 20,000miles after rebuild. 10w30 oil

when cold oil pressure is good (thick oil)
when hot oil pressure bounces at idle (thin oil)
oil pressure returns at or above 1,000rpms
when its acting up there is a grown/deep humm comming from the motor
when this started the mil was triggered, cyl 1-2-3-4 misfire
the cam syncro is new
I can feel a lack of power but no miss
mpg cut in half about 8-9mpg


what the hell am I missing?????


the oil pressure, noise and the misfires are all connected.



Any help is wlecome, and thanks....

 

[Viper Command]

Ok I think I have it figured out,

spun bearing (rear main) thus causing oil pressure droping when the bearing and the oil gally hole are not lined up, but spinning does send some oil through.

I pulled the cps to verfi the oil pump is spinning and the drive gears are still spinning.

I ran my drill on my oil pump, very hard to keep high rpms, I smoked my drill spinning that damn pump.

I removed the oil filter then spun the pump it was very easy now, so I opened up the oil filter there was a lot of metalic powder shavings but there was a pressure release valve in the event the filter is cloged so I know the filter is not the problem.


Does anyone have any other options on what is happening.

thanks

 

[Rearanger]

spun bearing (rear main) thus causing oil pressure droping when the bearing and the oil gally hole are not lined up,

I opened up the oil filter there was a lot of metalic powder shavings

Does anyone have any other options on what is happening.

You need more?

 

[Viper Command]

I dont have the motor out or apart yet, the wife is still using it to take the little one to school(4 blocks away).

come friday night parts and tools will be flying. Im shooting for a 6 hour turn around time. I know im dreaming....

 

[Big Jim M]

We'd best be looking at both rod and main bearings.. No matter what the journals look like I'd be putting the standard bearings in there if the thing hasn't been turned before.
I just MIGHT use some plastigauge to see what I have..
Big Jim

 

[Viper Command]

We'd best be looking at both rod and main bearings.. No matter what the journals look like I'd be putting the standard bearings in there if the thing hasn't been turned before.
I just MIGHT use some plastigauge to see what I have..
Big Jim

And cam bearings, I wish I could use plastigauge on the cam to make things easy.

I was wondering how long it would take you to see my posting.

 

[Tedybear]

Ok I think I have it figured out,

spun bearing (rear main) thus causing oil pressure droping when the bearing and the oil gally hole are not lined up, but spinning does send some oil through.

I pulled the cps to verfi the oil pump is spinning and the drive gears are still spinning.

I ran my drill on my oil pump, very hard to keep high rpms, I smoked my drill spinning that damn pump.

I removed the oil filter then spun the pump it was very easy now, so I opened up the oil filter there was a lot of metalic powder shavings but there was a pressure release valve in the event the filter is cloged so I know the filter is not the problem.


Does anyone have any other options on what is happening.

thanks

Here's going to be a headache no matter what you do. If you've triggered the pressure valve---the oil filter gets bypassed in order to keep the oil flowing to the engine. That means the shavings are now in every oil gallery within the engine--lifters--etc...

The only way to clean them out? Would be a full tear down--removing the gallery plugs...and cleaning the passage ways out. Anything else? Is going to be a short term fix only.

S-