I would still put an analoge gauge on it just for finality reasons. However it looks like you either drive it until it ceases which will cost you even more money or you tear it down for some exploritory surgery to see what the cause was. Most likely you have a wiped bearing(s).

 

Well, that's disappointing but now you might want to hook up a mechanical pressure gauge to verify the reading is correct; although I suspect that it is.

Although people think things like spun rod bearings with low oil pressure, the common cause of low pressure is worn cam bearings. If it were me, I would consider trying a 10w40 oil just to see if that bottom pressure improves. If it does, then you can live with thicker oil for a while or think about another motor, a rebuild or just drive it as it is. According to GM, the service limit is 6 lbs at idle - that's your red area.

I could be wrong about what to do so check with others before spending a lot of money. Maybe it's the pump but I doubt it with the 55 lbs at start up.

 

Your symptoms sound exactly like mine when I had a spun cam bearing.. Warm idle was as close to zero as you could get, rev it up it would get to 25 or so.. torn apart one of the cam bearings had moved in its journal and looked pretty darn ugly.

Before you go putting thicker oil in it make sure you don't have a bunch of small metal filings in your oil filter..

 

I drained the oil and it didnt have any metal, but I dont plan on driving it anymore

 

I remember reading some GM documents not to long ago. Most would be surprised what GM mandated for oil pressure. I don't recall the specs exactly, but at idle (800rpm) it was like 9psi. I don't remember the middle spec, but the high end spec (@ 4,000 rpm) it was only like 40psi.

It should be a comforting thought that you don't need excessive oil pressure in any motor. Remember, NASCAR motors run at 8,000+ rpm for 500 miles with only 45psi!!

 

Quick question, on the oil sending unit, is there any special tools required to remove it? I think this may solve all my problems.

 

nothing good, sounds like a spun bearing...

 

As already previously noted, you need a special oil pressure sensor socket (available at auto parts stores).

 

OKay thanks for the info shoebox. I must have miss read that somewhere

 

Just for those looking, found a few here...

Socket

Oxy

 

GM quoted me not long ago approx 10 psi.