Oil pressure is not good

bezzat

Member
After I accelerate the booster, the pressure rises
When I leave the accelerator pedal down, the pressure drops
What is the problem ?

Thanks
 
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Midwestdrifter

Engineer In Residence
How are you monitoring oil pressure? Where is the sender/gauge attached? What oil are you running? What year, and how many miles on the engine? What are your oil temps? Last oil change?
 

bezzat

Member
How are you monitoring oil pressure? Where is the sender/gauge attached? What oil are you running? What year, and how many miles on the engine? What are your oil temps? Last oil change?
my jeep is grand Cherokee 2.7 crd 2004
the engine same as printer TN1

I replace my oil before month 5-40 Valvoline full synthetic
from this site https://bevo.mercedes-benz.com/bevolisten/229.51_en.html

the engine do 285000 km
Before replacing oil I also had the same problem
 

sailquik

Well-known member
bezzat,
Can you provide us with some oil pressure numbers here?
If the pressure is ~50 PSI or greater when you are at highway speed and everything is a full operating temperature that
should be sufficient. Anything above 50 psi is even better.
When you stop and idle with the engine only turning 675 RPM (Normal OM-612/647 2.7 liter 5 cylinder and OM-642 3.0 liter V6)
the oil pressure will drop simply because the oil pump is not turning very fast.
Probably 25 PSI should be adequate at engine idle speed.
So, what pressures (the numbers please) are you seeing?
Roger
 

AdrianD

Member
That sensor is useless. In the local Jeep club and among acquaintances we've had close to 10 cars with "low" indicated oil pressure.
The sensor is on the turbo oil feed.

Just before the last Jeep trip my oil pressure seemed to have taken Viagra. Right after we started driving off-road, it went to show really really bad oil pressure, zero at 1500 rpm. And I drove like that over 100 km off-road, with steep climbs, mud, heat etc. If it was a real problem, I would have been looking for a connecting rod in the woods.
As soon as the off-road trip was over, the pressure was back to way more than what it used to be normal for the past 4 years. Viagra mode again.

It's normal for the pressure to fluctuate with RPM.

Next week I will have to change my oil and oil filter, for ****s and giggles I will cut the oil filter and look inside.

My car did have trouble with the oil pump because of some bad mechanics:
https://sprinter-source.com/forum/showthread.php?t=41168
 

slowgsr

Member
I installed a oil pressure gauge on my sprinter.
While hot running 0-40 devlac.
Cold I see 90psi, 70 to 80 at idle.
20-24psi at idle. Hot
Driving is typically rpm x2 plus 10.

Ie. 2500rpm is 60psi
2000rpm is 50psi
3000rpm is 70psi.

Before I had 15w40 t4 in it, once hot pressures are the same.
 

bezzat

Member
bezzat,
Can you provide us with some oil pressure numbers here?
If the pressure is ~50 PSI or greater when you are at highway speed and everything is a full operating temperature that
should be sufficient. Anything above 50 psi is even better.
When you stop and idle with the engine only turning 675 RPM (Normal OM-612/647 2.7 liter 5 cylinder and OM-642 3.0 liter V6)
the oil pressure will drop simply because the oil pump is not turning very fast.
Probably 25 PSI should be adequate at engine idle speed.
So, what pressures (the numbers please) are you seeing?
Roger
Unfortunately I do not have numbers .... I see only a clock that goes up and down ....
In the acceleration mode shows the clock on the middle (sometimes also in normal 750 in the comb)
How do I check numbers, what should I do / buy?
That sensor is useless. In the local Jeep club and among acquaintances we've had close to 10 cars with "low" indicated oil pressure.
The sensor is on the turbo oil feed.

Just before the last Jeep trip my oil pressure seemed to have taken Viagra. Right after we started driving off-road, it went to show really really bad oil pressure, zero at 1500 rpm. And I drove like that over 100 km off-road, with steep climbs, mud, heat etc. If it was a real problem, I would have been looking for a connecting rod in the woods.
As soon as the off-road trip was over, the pressure was back to way more than what it used to be normal for the past 4 years. Viagra mode again.

It's normal for the pressure to fluctuate with RPM.

Next week I will have to change my oil and oil filter, for ****s and giggles I will cut the oil filter and look inside.

My car did have trouble with the oil pump because of some bad mechanics:
https://sprinter-source.com/forum/showthread.php?t=41168
I also heard about it ... That's why I wrote here, you're my final seal

I installed a oil pressure gauge on my sprinter.
While hot running 0-40 devlac.
Cold I see 90psi, 70 to 80 at idle.
20-24psi at idle. Hot
Driving is typically rpm x2 plus 10.

Ie. 2500rpm is 60psi
2000rpm is 50psi
3000rpm is 70psi.

Before I had 15w40 t4 in it, once hot pressures are the same.
Can I install and see numbers?
Where was it installed exactly?
Can you describe it?
 
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AdrianD

Member
The oil port is on the block, below the oil cooler. If you look form underneath the car you should be able to find a 17mm bolt. I think the thread is M12x1.5 or M14x1.5.
 

bezzat

Member
Bottom Line ,
What is my problem? What needs fixing?
Where do I buy a mechanical watch with numbers and see what pressure?
 

AdrianD

Member
You can find some decent sensors on ebay, like this:
https://www.ebay.com/itm/1-8NPT-Sta...var=521728042440&_trksid=p2060353.m1438.l2649

The original sensor is the problem in your case. You could try to change it with a new one.

A couple recent oil pressure gauge failure stories:
A guy from the local 4x4 club had oil pressure problems on his Nissan 4.2 diesel, rebuilt the engine and still did not fix the problem. Eventually he tested oil pressure with a good sensor and everything was perfect.
My mechanic friend disassembled an OM612 from a Grand Cherokee completely to find out what the problem was with the oil pressure. He did not find anything unusual.
 

bezzat

Member
You can find some decent sensors on ebay, like this:
https://www.ebay.com/itm/1-8NPT-Sta...var=521728042440&_trksid=p2060353.m1438.l2649

The original sensor is the problem in your case. You could try to change it with a new one.

A couple recent oil pressure gauge failure stories:
A guy from the local 4x4 club had oil pressure problems on his Nissan 4.2 diesel, rebuilt the engine and still did not fix the problem. Eventually he tested oil pressure with a good sensor and everything was perfect.
My mechanic friend disassembled an OM612 from a Grand Cherokee completely to find out what the problem was with the oil pressure. He did not find anything unusual.
I wish it was just a sensor.......
So what kind of fault do you replace "BEARING-CONNECTING ROD" 5102066AA
https://www.moparpartsgiant.com/parts/mopar-bearing-connecting-rod~5102066aa.html
 

AdrianD

Member
Did you check with a different gauge? Or are you still going with the reading in the dashboard?

As I previously said, in my case (and a lot of other cases in Romania) it's just the sensor. Oil pressure was ok, then it went to zero for a whole weekend of off-roading, then it was ok again.
 

lindenengineering

Well-known member
Here are some Pro suggestions and the basic approach used in a shop to determine such issues .
Install a Genuine oil filter cartridge and verify the oil is the correct spec.
Install a good known accurate mechanical Borden tube gauge to the plugged gallery port.
Conduct the test and determine is a faulty exists .

If a low oil pressure condition exists the likely problems are .
Defective anti cavitation valve in the timing case
Defective oil pump or internal screen plugged .
Feed O ring to block gallery ruptured.
Under piston cooling jets defective or fell out!
Crankshaft and bearings worn to excess.
Structural defect in the cylinder block, cracked, main cap half loose, fixing bolt relaxed or has fell off.
Dennis
 

bezzat

Member
Here are some Pro suggestions and the basic approach used in a shop to determine such issues .
Install a Genuine oil filter cartridge and verify the oil is the correct spec.
Install a good known accurate mechanical Borden tube gauge to the plugged gallery port.
Conduct the test and determine is a faulty exists .

If a low oil pressure condition exists the likely problems are .
Defective anti cavitation valve in the timing case
Defective oil pump or internal screen plugged .
Feed O ring to block gallery ruptured.
Under piston cooling jets defective or fell out!
Crankshaft and bearings worn to excess.
Structural defect in the cylinder block, cracked, main cap half loose, fixing bolt relaxed or has fell off.
Dennis
thanks

I wants to replace my sensor

AdrianD
you give me link to sensor that not fit the original electric connector
what is part number ?
sory about digging
 

220629

Well-known member
Being an old guy... I actually like regular old analog mechanical gauges. In a similar situation I would explore adding a mechanical gauge.

I did a similar thing, but in reverse. My 1974 Dodge B series van came with an oil pressure gauge, but no idiot light warning. Even though I try to watch gauges I know that I'm not always diligent AND other people might drive my van. I installed a tee and added an oil pressure switch with a light on the dash. Rather simple actually.

Redundancy isn't really necessary. It is fairly inexpensive. Actual data will take the stress out of ignoring an electric monitor which has some history of being unreliable.

:2cents: vic
 

AdrianD

Member
Actual data will take the stress out of ignoring an electric monitor which has some history of being unreliable.

:2cents: vic
My weekend offroading with "zero" oil pressure has first been stressful (is my engine gone?) and then downright annoying (stop the car, BEEP, move a bit, BEEP again).
 

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