Oil Pressure is low

[Glenn C.]

I had the Pistons,rings, and cam shaft replace 50,000 miles back . When i got it back from shop the oil pressure was lower than before I had the work done. I pull boats with the 6.5/93 Chevy and have driven over 50,000 miles on these engine repairs and the oil pressure stays around 10 # after it warms up. I did not have the oil pump and pump filter changed . Any suggestins? Could it be as simple as an oil pump and pump filter, or maybe something else. Thanks in advance for help.PS I did have the block machined to match the new pistons.

[Peter J. Bierman]

Who is telling you the pressure is low?
Often lesser quality gauges are way off.
If you oil pressure really is that low, your engine would have died way back.
Check gauge first before you dig in the engine.

Peter

[tom.mcinerney]

Glenn--
Recent engine teardowns and communications on this forum indicate that the integral pressure-bypass valve in the 6.5L oilpumps can fail [spring breaks] causing low oilpressure, and eventual untimely death of powerplant.

Search in 6.5L forum to find relevant posts; i think last winter/spring; 'John8662' was a key.
See, for example:
http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007146


All the OEM gages are suspect after time. Pressure in a healthy rig should be more like
30/60 idle/run than 20/40 {or 10/~}. I'd try a dedicated aftermarket gage, then renew oil pump.

[ 09-04-2004, 06:18 PM: Message edited by: tom mac 95 ]

[Stray Cat]

CHeck the gauge...if it is good, try replacing the sensing unit.

[john8662]

Here was my experience with the ol oil pump.


Lower oil pressure than normal, things I can check (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006320)

&

Stud Girdle Kit and Oil Pump Questions (98+ pumps) (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006515)

You'll want to rig up a mechanical oil pressure gauge that you can get at a local auto store pretty cheap. I paid $10 for mine. Then go to your local hardware store that has plumbing supplies and adapt the connectors that come with the gauge to the thread found on the turbo feed line. That way at least you'll narrow out a gauge problem, you don't want to drive it that way at all.