Normal Oil Pressure?

[scliny65]

Okay, i changed the oil and filter about 300 miles ago.

The pressure looked good at about 40 when idling, and it rises slightly when on the throttle.

Now, it sits right around the bottom of the normal range, as indicated on the factory gage when idling, but does rise over the 40 mark when driving.

What gives?



This is a 97 SLT with 56k on it. I have owned it since this time last year. I bought it with 43k on the clock.

Is there a problem looming on the horizon that I should be looking for?



One side point: the idle is on the low side (600 rpm's) I can't seem to find the idle speed adjustment.



Can somebody give me a hint, the Haynes manual is pretty useless for this one. Am I correct in assuming that the low idle speed is definitely the reason for the low oil pressure?



Thanks in advance guys.

 

[chuck3]

Mine runs a little below 40 idling after it has warmed up, but around 45 when running down the road.

 

[SnoKing]

Steve, if you hold the idle at 800 RPM with the foot throttle, what does the pressure read. Also are you sure you used 15W-40 Diesel engine oil like Chevron Delo 400? Also hope you used the correct Fleetguard filter.



SNOKING

 

[xbubblehead]

From reading your post it sounds like you are seeing significantly different oil pressures readings immediately after performing your last oil change. What type & weight oil and what type of filter were you using before the oil change and what are they now. To me it sounds like you switched to a lighter oil and/or a more restrictive oil filter.

 

[scliny65]

Oil Pressure

SNOKING; xbubblehead:



at 800 rpms it is right around 40.

I am running 15-40w Rotella T, and a Puralator filter, which is the direct stock replacement item.

The filter I replaced was a fleetguard.



Do either of you know where the idle speed adjustment is?

I really need to boost it, since when running full lights, and the AC while in drive, she gets real rough and the idle is around 500 at that point.



I believe the manual says that the idle speed, for those conditions, should be a little higher than 800, right?



Thanks guys!

 

[Evan A. Beck]

To adjust the idle, all you need is a 10mm wrench, a light, and some patience if you have never done it before.



Here's a picture of the adjustment screw. DO NOT adjust the linkage that goes from the back of the pump to the front. That is the full throttle adjustment, and should not need to be tinkered with. I like to set the idle at 850-900 on a warm engine.