6.0 oil pressure issue

[77c10]

I recently swapped a 2005 6.0/4L60E into my 77 c10. The engine had 225k plus miles on it when I got it. I never personally heard it run but was told by the guy that I bought it from that it held good oil pressure but had the normal LS lifter tick at idle. I tore into and below is a list of parts I replaced.

Main bearings
Rod bearings
Oil pump
Lifters
Timing chain
front and rear seals and gaskets
oil pan gasket
head gaskets
valley pan gasket
intake gasket

My issue is that my Autometer oil pressure gauge only reads around 10psi at start up. It goes up a little when you give it gas but not as much as I think it should. I tried a secondary mechanical gauge and get basically the same reading.

I have the sending unit in the location where the factory sending unit went.
I've pulled the plug on the left front of the engine and the one above the oil filter and both puked oil while cranking.
There isn't any knocking or rattling like I think there would be if it did actually have low oil pressure.

Does anyone have anything else to try?

Thanks in advance

[chuckmc8]

If you have an accurate mechanical gauge plumbed into the factory sender port and it reads 10 PSI that is what you have. Just for additional confirmation you could try another mechanical gauge to be absolutely sure- but the two gauges you have read the same. HTH

[Willie Makeit]

sounds like you may need some cam bearings

[77c10]

Originally Posted by Willie Makeit

sounds like you may need some cam bearings

Do you think it's possible to replace the cam bearings with the engine still in the truck?

[akdg87]

225k is quite a bit but there is the chance you used the wrong o-ring for the pickup tube, or possibly even pinched it while installing it.

[mongocanfly]

Nothing to do with the oil pressure but did you change the bolts when you replaced that stuff on your list...i noticed you didnt list them...LS bolts are torque to yield one time use bolts..

[chuckmc8]

After thinking about this overnight, I tend to agree that is is very possible that the oil pickup to the pump seal is compromised. There are many many LS engines purring along with 225k on them

[77c10]

Originally Posted by chuckmc8

After thinking about this overnight, I tend to agree that is is very possible that the oil pickup to the pump seal is compromised. There are many many LS engines purring along with 225k on them

We had the pan back off of it Saturday and triple checked the pick up tube and o-ring. It doesn't appear to me that it is compromised at all.

[77c10]

Originally Posted by mongocanfly

Nothing to do with the oil pressure but did you change the bolts when you replaced that stuff on your list...i noticed you didnt list them...LS bolts are torque to yield one time use bolts..

I replaced the head bolts. Those were the only ones I knew that were torque to yield.

[Willie Makeit]

Originally Posted by 77c10

I replaced the head bolts. Those were the only ones I knew that were torque to yield.

the harmonic balancer/pulley bolt is another that is often overlooked

[77c10]

Originally Posted by Willie Makeit

the harmonic balancer/pulley bolt is another that is often overlooked

I stand corrected, I also replaced the balancer bolt as well. Totally forgot about that one! What a PITA to get the old one loose!

[77c10]

With hindsight being 20/20, I should've pulled the cam retainer plate while I had the front cover and timing chain off, pulled the cam and visually checked the bearings.

[Big Port Jimmy 6]

The last oil pump I bought came with several pick up O rings. Make sure that you used the right one. They are very close in size and easy to confuse. Jay