Oil pressure?

[Burner]

When my truck is at Idle it has only 26 to 29 lbs of oil pressure. Is this normal? As the motor revs it goes up to 60lbs or a little higher. This is after the motor is warm.


Burner

[AbqGeorge]

I've got the same characteristics with mine. I'm thinking they've done something to lower the very high pressures the '01 and '02 folks were/are seeing.

Anyone know for sure? Inquiring Minds Want to Know tongue.gif

[Wally]

Seems a little low.
First I would suspect the oil pressure sending unit. In the meantime I would also check to make sure that you don't have fuel in your crankcase.
A problem in the fuel system could explain your loss of power and depending on what is wrong could also dump fuel into the oil, diluting it and causing a low oil pressure indication.
Mine idles at about 45 psi and runs with about 65-68 (hot).
Cold it idles about 60 and pegs the gauge at any speed above idle.

[mackin]

I would say it's fine.....

The spec for 01 is =>Oil pressure @ 3250 RPM 56.89 psi

MAC

Wondering here, some pre info......Those with Auto Tap or equivelent,how do you find the accuracy of the stock gauges????

Looking forward to getting this new tool and put it into action....Puter being built,YAAA, will order AutoTap soon.....

[ 12-17-2002: Message edited by: mackin ]</p>

[SoCalDMAX]

Wally,

I think you'd be very disappointed to find out how inaccurate the factory gauges are. Even a broken clock is correct twice a day. ;) In the morning at 40* or below, your gauge is pegged at 80psi, when in reality it's in excess of 140psi on startup, just off idle.

Once warmed up, with an oil temp of 170-180*, an indicated 35psi at idle is actually 23-25psi. This decreases with oil age and temp. Driving down the road at 1900rpm, an indicated 75psi is actually 65psi.

None of these numbers are alarming to me by themselves, but I now rely heavily on the oil press/temp gauge I installed myself. The IP gauge is reassuring to watch as it goes up and down with RPM, but I don't consider the numbers to be very accurate.

On the plus side, tranny temps measured in the sump are quite often 20-40* lower than the gauge indicates. Even towing, when my IP tranny temp gauge indicated 185*, it was actually 140-150*, almost too cool. I'd be in heaven if everything warmed up to 180* and stayed at that temp all of the time. Considering the amount of power produced, heat generated, varying weather conditions and varying loads placed on these trucks, I'd say GM erred well on the side of overkill for all of the lubrication and cooling systems.

Regards, Steve

[Wally]

I don't doubt for a minute that the factory gauges aren't spot on. However they are amazingly consistent from one truck to the next. Burner's pressures are within spec I'm sure but they also indicate lower than the vast majority of trucks out there. I mentioned the fuel thing because for several members a lower oil pressure was the first clue that they had fuel in the oil.

Never hurts to check. If their is no sign of fuel contamination then I wouldn't worry about the readings.
Unlike one of the other brands at least our gauges move :D

[conradv]

Burner,

Those are my numbers exactly on my '03 GMC.

[jbplock]

Steve,

I'm curious about the 140 psi you saw at 40degF cold start. What type of oil was that with? I'm looking at different oil bypass filter setups and I'm concerned about max oil pressure.

[polaris800]

Why does the 2003 show very low oil pressure when engine is warmed up. My shows to just a line over the first quarter mark. I think that is around 25/30 psi at idel. When im driving it goes to 40/60 and stays there. Just another change for the 2003. GM is always changes some thing to **** off the buyer... This is just the start os the 03 concerns I have.

[johnpugh]

Burner:

I get the same numbers on my '03 when warm. At idle, it hovers around the 30 mark. Off idle it appears to track with RPM.

Later.......

[NoMo]

Ditto my '03.

~30psi at idle and ~60psi at 60mph

PS: my truck also "ticks".

[Searay90]

Please remember that the oil pressure guage is not the same on the 03's as what was used on the 01&02's. The 01&02 have an 80psi guage, and the 03's have a 120psi guage. So when one says it is registering 1/4 in the range.... it's comparing apples to oranges between the different years. :eek: