Neep Help ASAP.. 6.0 Problems... - Diesel Forum

Mad Max · 03-22-2009, 03:31 AM

I scanned a friends 04 6.0 tonight and the HP Oil Pressure is dropping off like a rock as soon as the go pedal is hit. The pressure hits about 3000 PSI for about 2 to 3 seconds and then drops to about 1000 PSI.

The truck is also having a hard start problem. After the truck sits for a while it will not build HP pressure until it cranks for a long time. It finally builds enough pressure to start after about 20 to 30 seconds of cranking.

We also checked the low pressure oil and we are only seeing about 4 to 5 PSI at idle and 40 PSI above idle. Is this normal for a 6.0???

No knowing the 6.0 like I know the 7.3 I am taking a SWAG that it could be the HPO Reg O-Rings or the HPO Regulator. This truck has 513K on it and still rides and drive great.

This truck needs to get back on the road ASAP. It is used as the main income for a friend of mine and it loaded and ready to go as soon as we get the problem fixed.

Thanks,

Barry

RatherBNtheWoods · 03-22-2009, 06:03 AM

I'm going to say that 4-5PSI for lube oil pressure is not good or normal. I believe I would follow that path, first by confirming it is only 4-5 then find out why. If it is that low, that may not be enough pressure/flow to keep oil in the HPOP reservoir, so the HPOP can't make good pressure.

RoyC · 03-22-2009, 09:41 AM

Per the 6.0 Bible, oil pressure from pump is regulated to 75 psi by a oil pressure regulator located just below the oil pump. The regulator may be stuck open, pump may be bad ETC.

I would look at look at oil pressure as stated above.

Roy

Mad Max · 03-22-2009, 01:10 PM

At what RPM is the 75PSI at???

painsonlyapulse · 03-22-2009, 02:34 PM

sounds like you have a high pressure oil leak... if its still under warrenty get it into a dealer and have them fix it. being that it still starts its probably just a dummy plug in one of the oil rails.

Mad Max · 03-22-2009, 06:31 PM

It has 513K miles so no warranty... He is checking for leaks under the valve cover...

JAKE8842 · 03-24-2009, 01:32 PM

Possible it is a low pressure oil problem but first thing i would check is the hpop. Very common for the plug to blow out of the side of it....

manitoba-rancher · 03-26-2009, 10:07 PM

How much is it to replace the oil pump??? For jsut the parts

md18 · 03-26-2009, 10:15 PM

Minumum oil pressure specifications from AllData
At operating temperature:
12 PSI @ 700rpm
24 PSI @ 1200rpm
45 PSI @ 1800rpm

If that was an accurate reading of your oil pressure than i would start diagnosing why your base oil pressure is so low...

Texascadillac42 · 03-26-2009, 10:54 PM

Quote:

Originally Posted by JAKE8842

Possible it is a low pressure oil problem but first thing i would check is the hpop. Very common for the plug to blow out of the side of it....

I just went through this exact same problem with an 04 6.0L. LPO system was only registering 5-10psi at cold high idle, and basically 0 at hot idle. Turned out to be the ball that is pressed into the side of the HPOP. I put in a new HPOP and everything was fine. Hard starts went away, and more importantly, the low pressure oil went way back up. 30psi at hot idle, 60-65 running down the road, and 60psi at cold idle.