[dkovac]

when i start my K1500 up i get oil pressure at closer to 60 pounds then when driving at speed on the highway it drops to 40 pounds stopping at a red light etc drops it to 20 pounds
this just started to happen never noticed it this summer when i got the truck

normal or a problem brewing??

Thanks

D

 

[The Rockslut]

A good standard to go by is 10psi for every 1000rpm minimum Also the gauge can be going south Those pressures dont sound bad at all. If you are that concerned I would install a mechanical gauge and watch it.

 

[4x4realm]

My blazer the presure doesn't change that much but the truck I drive at work (93 3/4 ton 350 tbi) the presure seems to run about like what you discribed about 40 on freeway and 10-20 at a stop light. It's done that sents it was new.

 

[dkovac]

thanks guys

 

[jakeoffroad]

dude, i noticed my trash does about the same thing and i have an old school 350. i guess as the engine warms up the oil press drops. it still runs so i dont care <IMG SRC="smilies/usa.gif" border="0">

 

[Black Dog]

Those are good oil pressure readings. No problem whatsoever.

 

[ranger]

As long as you have positive oil pressure your good to go. Just remember when temps rise you oil viscosity breaks down, lowering operating pressures.

 

[dkovac]

I realize i will drop pressure as the oil warms up, thats why i am a little worried i never had this problem in the summer months with temps in the 90's
I just thought of a reason though
I did have one of the guys at work (i'm a car salesman) change the oil he could have put 5 weight oil in this would probably account for the pressure drop due to the thinner oil

 

[ranger]

Yep, if the dude put in a thinner oil in your truck it would cause your pressure to drop. <IMG SRC="smilies/skull.gif" border="0"> No worries!

 

[coyote]

So I've heard the 10 psi for every 1k rpms but when my system gets up to temp 180-190 my pressure drops to less then 10 (mech gauge) at idle and 650 rpm...it does climb quickly and I know that pressure and flow aren't the same and I have plugged the bypass to send the oil through the filter 100% and use 20w50....engine doesn't knock and have had the problem for awhile and haven't noticed any other problems....might try replacing the filter plate with the bypass unmolested....any ideas?????

 

[Sidewalk]

This is the spec for every engine I have worked on (except Harley ):

15 psi minimum at idle
45-60 psi at operating speed (2000 RPM for my BII)
75 psi max

This goes for my little VW, as well as the Fair-Banks Morse deisels that are the size of my house.

 

[6869704x4]

If there is a change all of a sudden then something happened. The oiling system is actually more reliable than the indicating system. A cheap mechanical gauge is a good troubleshooting tool.

Here is some good info http://www.melling.com/support/bulletins/default.asp