Low oil pressure

u2slow

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I'm plagued with low lube oil pressure on my '97 E350.

Done a fair bit of diagnostics already. Minimal results. Oil pressure is currently 5psi at the hpop reservoir, and 10psi at the block with a new Melling pump. This is after letting it idle for 5-10 mins from being dead cold.

I have confirmed that I have the revised cooler/filter header with the snap-rings on the bypass and relief valves.

The few other possibilities I have read about are:
- oil pump pickup (drawing air i.e. cracked, bad gasket, etc)
- stuck/faulty bypass valve (however unlikely with my snap-ringed header)
- wiped out thrust bearings (ballooned torque converter)

Who's got ideas how to isolate this further? :angel:
 

Goofyexponent

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Well, from what I gather low oil pressure can amount to a series of events.

What are your main bearing telerances?

Is the oil pump working correctly?

Are you using an aftermarket gauge?

Is THAT working right?

What does your oil look like?

Any particles in it?
 

u2slow

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Well, from what I gather low oil pressure can amount to a series of events.

What are your main bearing telerances?

Unknown... not going in there yet.

Is the oil pump working correctly?

I assume so. I picked up 5 extra psi at the block ear, and now my gauge registers at the hpop reservoir. Gauge doesn't really register below 4-5 psi.

Are you using an aftermarket gauge?
Is THAT working right?

They are mechanical process gauges.

What does your oil look like?

Any particles in it?

Dark with carbon. Just like my F350. Oil goes black pretty quick. I cant detect any metal particles, but the factory idiot-gauge has been cutting in and out since I bought it 3-4 years ago, so I know the pressure has been down for some time. I can send out an oil sample for analysis, but seems a bit out in left field for diagnosing a pressure problem.
 

OLDBULL8

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Done a fair bit of diagnostics already. Minimal results. Oil pressure is currently 5psi at the hpop reservoir, and 10psi at the block with a new Melling pump. This is after letting it idle for 5-10 mins from being dead cold.

10 PSI when idleing is normal with a hot engine. These oil pumps pump volume, not pressure per se. 40 -55 PSI at 1800 RPM is normal.

With 15W-40 oil, and a cold engine idleing, oil PSI will be around 20-40 depending on the milage.
 

Double-S-Diesel

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was the pressure low before ya changed the pump.
is the pump installed correctly.
what did the front cover look like.
 

u2slow

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10 PSI when idleing is normal with a hot engine. These oil pumps pump volume, not pressure per se. 40 -55 PSI at 1800 RPM is normal.

With 15W-40 oil, and a cold engine idleing, oil PSI will be around 20-40 depending on the milage.

Engine is not hot because I really don't aspire to drive it with such low oil pressure. I get to about 20psi cold revving it. I believe I'm still running SAE 40w oil (not multiviscosity). The van has 270,000km on it.


was the pressure low before ya changed the pump.
is the pump installed correctly.
what did the front cover look like.

Pressure has INCREASED approx 5psi at the hpop res. and at the block ear since changing the pump. The timing cover looked good. The Melling comes with a whole new snout housing. Pretty no-brainer to install IMO.

Anyone got tips for isolating my pressure loss? Any tips for the diagnosing the byapass valve without removing the cooler?
 

NJKen

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The best thing you can do is start taking it apart and start measuring. I know it sux but I think you have done everything you can from the outside.
Ken
 

Goofyexponent

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I still think an oil sampling would help determine if there was something that came apart. Thrust washer, main bearings, etc would show up by material in the sample. If you dont have to take the motor apart out of the truck (if you don't need it as a daily driver) I would do the sampling and let it sit until it comes back with an analysis.

Other than that, looks like it's time to break out the plasti-gauge, calipers and feeler gauges. That sucks.
 

OLDBULL8

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[Anyone got tips for isolating my pressure loss? Any tips for the diagnosing the byapass valve without removing the cooler?
/QUOTE]
I wouldn't think the bypass valve would have anything to do with low pressure, that only opens if the filter is plugged and oil pressure should remain the same from the pump.
Here is the oil flow from an IDI but is basically the same for the PSD.
You must be registered for see images
 

u2slow

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The best thing you can do is start taking it apart and start measuring. I know it sux but I think you have done everything you can from the outside.
Ken

This is van.... any idea if the oil cooler can be slipped out like it can on the F-series?

I still think an oil sampling would help determine if there was something that came apart. Thrust washer, main bearings, etc would show up by material in the sample. If you dont have to take the motor apart out of the truck (if you don't need it as a daily driver) I would do the sampling and let it sit until it comes back with an analysis.

Other than that, looks like it's time to break out the plasti-gauge, calipers and feeler gauges. That sucks.

The oil presssure has been low for so long. The stock idiot-gauge had been cutting in and out right from then. I had trusted a mechanic friend of mine on his advice not to worry about it - its probably the sensor or the cluster... bad advice anyways.

There probably isn't more than 1000km on the current oil. Do you think there would be anything in the oil relevant in a sample analysis? Its not a DD anymore. I'd like to have it roadworthy though for my friend who'll be babysitting it when I ship out in 6 weeks.

there is a front side and a back side when instaling the new one

Yup. Got that.

I wouldn't think the bypass valve would have anything to do with low pressure, that only opens if the filter is plugged and oil pressure should remain the same from the pump.
Here is the oil flow from an IDI but is basically the same for the PSD.

There's two valves (I forget which is which) but one cuts the oil filter when is becomes clogged, and the other dumps excess oil pressure right back into the sump.
I've been studying this pdf:
http://www.forddoctorsdts.com/artic...49873DITDirectInjectionTurbochargedDiesel.pdf

I'd love to put a pressure gauge in the oil cooler header, but the van header doesn't have a spot unless I physically make one. Kind of hard to do if I can't slip the cooler out.

Great discussion guys! Keep it coming! ;Sweet
 

NJKen

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I know vans are a ***** but sometimes there is only one good way to get to the truth.
 

Double-S-Diesel

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not shure how to pull an oil cooler on a Van
had a f550 once the oil pump was wore .024, well beyond spec, but still held 20 psi at idle.
had a 350 that the rear main was all but toast and the thrust side was wiped out completely, no loss of pressure by the factory guage.
not shure what next, maybe swap the oil cooler, gotta be easiser than pullin the motor to check bearings.
 

sassyrel

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not shure how to pull an oil cooler on a Van
had a f550 once the oil pump was wore .024, well beyond spec, but still held 20 psi at idle.
had a 350 that the rear main was all but toast and the thrust side was wiped out completely, no loss of pressure by the factory guage.
not shure what next, maybe swap the oil cooler, gotta be easiser than pullin the motor to check bearings.

heres another scenario---brother had a 88 7.3..start,good psi, as soon as warm,zero. so,took off the rear cooler header--and the relief valve was----------------STUCK OPEN!!!!!!-------i took it home,polished the valve with FINE scotchbrite, and staked it back together. he had good oil pressure, even on the day he traded it off for a way newer one. we went thru a bunch of other things before discovering this-----all it takes is one little particle to get in that valve,jam it sideways, and goodbye oil pressure--
 

sassyrel

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[Anyone got tips for isolating my pressure loss? Any tips for the diagnosing the byapass valve without removing the cooler?
/QUOTE]
I wouldn't think the bypass valve would have anything to do with low pressure, that only opens if the filter is plugged and oil pressure should remain the same from the pump.
Here is the oil flow from an IDI but is basically the same for the PSD.
You must be registered for see images

read above response--
 
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