High oil pressure - 3126 engine

Tennesseahawk · Aug 16, 2012

Getting high oil pressure. Mechanic said it could be an oil pump, or just a sensor. He also mentioned another part I forget, that shouldn't go out til around 750k (I have 526 on mine).

Any ideas?

EASYTRADER · Aug 16, 2012

Get ur oil sampl3d, it migh5 be contaminated, likely its a sensor, though

Sent from my GT-P3113 using EO Forums

Tennesseahawk · Aug 16, 2012

EASYTRADER said:
Get ur oil sampl3d, it migh5 be contaminated, likely its a sensor, though

Sent from my GT-P3113 using EO Forums

Just got an oil change yesterday. He said dirty oil would've done the pump. I didn't think 12k was too long for an oil change. I guess it is.

zorry · Aug 16, 2012

Years ago a driver called in NO OIL PRESSURE.
Father said,probably a guage or sending unit.
It was an oll pump. Lost the engine.
Expensive lesson.
Most likely a sensor, but if oil pump is failing,you want it checked NOW.
Tomorrow may be too late.

purgoose10 · Aug 16, 2012

Oil pump on a Cat is an easy fix. If you don't mind getting your hands dirty. I would change the sensor and then check the pressure before you go out on a load. It will tell you right away.

Tennesseahawk · Aug 16, 2012

zorry said:
Years ago a driver called in NO OIL PRESSURE.
Father said,probably a guage or sending unit.
It was an oll pump. Lost the engine.
Expensive lesson.
Most likely a sensor, but if oil pump is failing,you want it checked NOW.
Tomorrow may be too late.

Thank you for that! Initially, I was going to run it until I got it checked out. The pressure hovered between 75 and 85, so I thought it would be ok. The more I thought about it tho, I didn't want to risk the truck on a hunch. You've confirmed my fears.

zorry · Aug 16, 2012

Oil change yesterday. Did you get the wrong filters ? 50w oil ?
Unless problem started before the oil change.....

Tennesseahawk · Aug 16, 2012

zorry said:
Oil change yesterday. Did you get the wrong filters ? 50w oil ?
Unless problem started before the oil change.....

It started the day before I got the oil change. Then afterwards, the pressure started out a little high, dropped to normal (50) for about a half hour, then jumped up around 75. The day before I got the oil changed, it shot up around 100 at high idle, for a few seconds. Then it was at 75-85 most of the day, then it dropped to normal for a short time before returning to 85. One thing that I found weird was it dropped back to normal after running the A/C on high.

Deville · Aug 16, 2012

Ok, if you are pushing that much pressure & it's not a sensor issue than you may experiance gaskets leaking, particually around the oil cooler under the turbo.

How is it running? I know you said it started the day before. Are you sure the shop did not overfill the motor? The truck stop i used once over filled my motor by a gallon. The truck did not run right, it was drowning in oil, but I had normal to slightly lower than normal oil pressure but no power what's so ever, especialy on hills.

I've never dealt with an oil pump issue ever. Is the CAT oil pump electrical or mechanical? I assume it's located in the oil sump/pan.

Mdbtyhtr · Aug 17, 2012

you could have a sticking pressure relief valve on the oil pump, that is a cup like piston and a spring designed to pop off when the oil pressure becomes too high. When they stick, you can blow oil filters off and result in catastrophic engine failure due to lack of lube. Because you had the problem before the oil change, you can rule out oil filters. Another thing that can cause high oil pressure is cam bearings turning in their bore. Diagnostically, check the easy things first, like a manual oil pressure gauge to check against the on in the dash.

Best of luck,

Scott

Tennesseahawk · Aug 17, 2012

Mdbtyhtr said:
you could have a sticking pressure relief valve on the oil pump, that is a cup like piston and a spring designed to pop off when the oil pressure becomes too high. When they stick, you can blow oil filters off and result in catastrophic engine failure due to lack of lube. Because you had the problem before the oil change, you can rule out oil filters. Another thing that can cause high oil pressure is cam bearings turning in their bore. Diagnostically, check the easy things first, like a manual oil pressure gauge to check against the on in the dash.

Best of luck,

Scott

That's what they're doing. I'm hoping it's the sensor, since the pump installed is over $900.

Thanks for your answer.

Tennesseahawk · Aug 17, 2012

They're thinking it's the sensor or a wiring problem. They're hooking up a mechanical gauge right now. I'll take it out for a test drive this weekend, and should be good to go.

Thanx for everyone's' help.

Tennesseahawk · Aug 30, 2012

High oil pressure problem fixed. Now I have low oil pressure. When driving, it's around 28. When it's idling, it's around 5 or less.

Being that it was likely debris in the oil pump to cause the high oil pressure, would it take a rocket scientist to deduce that the oil pump may be on its last legs, and is causing the low oil pressure?

Tennesseahawk · Aug 30, 2012

Also, when the shop changed the oil, they put too much in it... maybe 2qt to a gal. Could this cause low oil pressure?

purgoose10 · Aug 30, 2012

To much in a Cat can lower the pressure. 28 sounds about normal for idling and low RPMS, should run about 40 psi normal operation. 5 is way to low, check your guage.

jelliott · Aug 30, 2012

Tennesseahawk said:
High oil pressure problem fixed. Now I have low oil pressure. When driving, it's around 28. When it's idling, it's around 5 or less.

Being that it was likely debris in the oil pump to cause the high oil pressure, would it take a rocket scientist to deduce that the oil pump may be on its last legs, and is causing the low oil pressure?

Sounds like it to me.

Tennesseahawk · Aug 30, 2012

Talked to a mechanic at Cat. He said extra oil wouldn't do anything to the oil pressure; but I read it could blow the seals.

He also said that anything below 18 should get a low oil pressure warning, and an engine shutdown. He said that the gauge could be bad.

He also stated, when asked about the pump causing it, that it was unlikely, but possible.

I just don't know what to do. I have to hit the nail on the head the first time. I guess checking the gauge should be #1 on the list.

Tennesseahawk · Aug 30, 2012

Now I talked with ANOTHER Cat mech. He said the warning light wouldn't necessarily come on if the sensor is bad. He thinks it could be a pressure relief valve on the pump. I'm thinking I should just go ahead and change the oil pump. But then again, I might have damaged the engine. Maybe I should just have them check the relief valve.

I'm so confused.