question about dropping oil pressure

[vlmuke]

I have had my deuce for a year now and last fall is started dropping oil pressure after it warmed up so I changed the oil and during the winter I drove it a few time but since it was cold it dropped some but not a lot, but now that it is warm its seems to be getting worse when I start it up it reads 60 psi at idle and as it warms up it drops to 30 and last night it was less than 30 psi the oil seems pretty thin, I was wondering if its getting diluted by diesel some how? if so how? as the engine runs well doesn't burn oil, it was rebuilt in 10-89 by toole I have an ICE STE unit if that would help in diagnosing anything but I have never used it, if any one has any suggestions ideas or ways to solve this I would appreciate it thanks
Rich

 

[builder77]

It depends which numbers you are giving are at idle and which are at speed. If the 30psi is at idle then that is ok to me.

 

[doghead]

Is your FDC bypassed? You could do an oil analysis and find out if you have fuel in the oil.

 

[No.2Diesel]

I wouldn't start to panic . Pressure drop due to temperature increase is normal. As long as its over 10-15psi at idle (1,000RPM) and over 35-40psi driving around, your fine. Cold oil does not flow quickly and will oilways read higher on the gauge.

 

[vlmuke]

I got less than 30 at idle and just above 30 at about 10 mph in second gear, It say the fdc was bypassed by toole but I don't know if it still is or not as this is my fist deisel and i got from from a private individual so I'm not sure what he did or didn't do to it if the fdc is by passed what would cause fuel in the oil?

 

[doghead]

Even if the FDC is bypassed there is a possibility that you could have leakage in the IP allowing fuel into the oil. Oil analysis is the best way to test if you have fuel leaking into the oil.

 

[builder77]

From what you are saying it sounds fine. From what I have been told with gas engines10psi per 1000rpm is right. You need to be more specific though when giving info like this. Give specifically as close to the PSI as you can find determine on the Gage, and the RPM that the engine is going at when you get that reading. "I got less than 30 at idle and just above 30 at about 10 mph in second gear." is too vague. Could be 0psi at idle or 29psi at idle. Also I am not about to do the math, or drive my truck to get the RPM from 10mph in second gear.

Doghead is right if you have a concern about oil contamination then send in a sample for testing.

 

[alphadeltaromeo]

Hmm

My experience is that diesels will have high oil pressure initially and once they heat up it drops quite a bit...my CAT does that and so does my deuce. Once my deuce heats up, she runs at 29/30 psi consistently at 2600 RPMs on the highway. I'm not concerned at all and my oil is visually fine each time I inspect it. What I mean is that it's not making more oil, as rdixiemiller experienced with the FDC still in line.

Andy

 

[Boatcarpenter]

RE: Hmm

Don't forget that you can put in a mechanical gauge to check on your electrical one. Mine showed 30-35psi at all engine RPM's .Put in a mechanical gauge and got 30- 35 at idle and got 70psi cold and 60psi hot most any RPM higher than idle. Food for thought.
BC

 

[JasonS]

10psi/ 1krpm is probably OK for an SBC with tight bearing clearances. However, I wouldn't assume that is is OK for every engine and I certainly wouldn't apply that very rough rule of thumb to an engine which normallly has much higher pressure. If your oil pressure is low, there is a reason. Bearings, oil pump, guage/ sender, oil viscosity. Find out why before you develop a knocking sound...

 

[vlmuke]

I noticed that the oil level is higher than it should be so I am assuming its adding fuel to the oil, does anyone know what are ways to determine what is causing this? I know someone mentioned the injector pump and the FDC is there a way to diaganose this?
Thanks for all of your help
Rich

 

[gimpyrobb]

Oil analysis is the way to determine it.

 

[gimpyrobb]

Post a pic of the injection pump and FDC. We can tell if its been bypassed.

 

[vlmuke]

OK I'll dig out my camera and take a couple of pics

 

[vlmuke]

I finally found the time to take a pic of my injector pump and fdc can someone tell me it has been bypassed or not and if it has would fuel be getting in the oilvia the injection pump? or is there any other source?
Thanks for your help
Rich

 

[vlmuke]

Here's the pic of the IP and FDC

 

[BFR]

it is bypassed...there are some o-rings that seal the hydraulic head that could be bad...mine were

 

[vlmuke]

is there a manual for it, how hard is it to repair? do I need to pull the IP Thanks for the help

 

[willysmd]

How can you tell it is bypassed can someone let me know please.

 

[Boatcarpenter]

FDC Bypassed

This may help.