416yellowz

Hello everyone, I could use some words of wisdom from you guys.

I'm having a problem that's really worrying me.

The car has a lingenfelter crate motor in it that only has 4k miles on it. About 500 miles ago, the previous owner had to go through the motor and replace all of the bearings/etc because one of the arp bolts went into the motor and caused some problems. Everything was fixed at "wall2wall" and the car was back to normal.

Now here's my problem.. yesterday I noticed the oil pressure was reading 10 psi at idle at a red light. I gave the car some throttle on my way home while keeping an eye on the gauge, and it only got up to about 35psi at full throttle.
I parked the car overnight, and I went outside this morning and started it up. Oil pressure was normal (35 psi at idle and gets up to 60-80 when i give it gas).. so I decide to go drive it around for a bit. As the car continues to get warmer and warmer, the oil psi continues to get lower and lower. Once car was at full temp, the oil psi was back to 10psi at idle. There is no weird noises or knocking.
So car was towed to a shop this morning. First thing being checked is the sending unit (which i dont think it is because it usually gets pegged out at 0 or 100 when that goes bad).

My question is... if sending unit is working properly, where do i go next? Do i just change the oil pump and hope that fixes the problem? Or should I check the clearance of the new bearings? Just trying to go the route that will cost me the least amount of money obviously..
Any advice is appreciated..thanks

dryadsdad

Assuming the sender is OK, the list of what could be causing the problem gets huge. I doubt it'd be the oil pump but it could be. These usually outlast the car unless something goes through them which gives them indigestion.

I'd suggest first staring by listening to the engine with a stethoscope sort of arrangement if needed. Bearings with too much clearance make noise. In reality though, problem bearings should be audible with your bare ear.

I'd also, as a first step, remove the oil and filter. Examine both. Filter by dissection and oil by filtering through something like fine cheesecloth to look for metal. Then come back for some more suggestions if oil / filter is clear and the engine sounds good.

nerijusj

Start with a simple oil and filter change and see if that helps before doing anything else. I had the same happen on my 08 sierra truck. When I bought it at auction, it warmed up and oil pressure dropped, beeps to shut the engine etc.... First thing I did was oil and filter change. It solved the problem. Not sure what exactly was the problem, maybe just a bad filter....or oil overdue as it was very dark. Good luck!

timd38

I would send an oil sample in to see if there is bearing material in it.

Just another opinion.

Racer86

Problem solved.

cv67

x3 on cutting the filter open
Lingenfelter I believe warranties their engines unless some fine print rule somewhere was broken if anything they would have the motor and your Vin on file I bet. Think Ken is on this board (pretty sure thats his name)

timd38

Ken owns it but Mike Copeland is the guy running it. Great guy.

tennblkc6

unless I'm mistaken..I would think the first post above has the broken "fine print" you are referring to.

416yellowz

Sorry guys, i forgot to mention that i did change the oil/filter last night after i noticed the problem. I cut open the filter and searched through everything for any kind of metal shavings, and I couldn't find anything. Oil psi still dropped this morning even after the oil change

timd38

Send the oil in for analysis. Just becasue there are not any shavings doesn't mean that the bearings are not gone.

dryadsdad

Hood open, engine on. Any nosier than before the drop in pressure?

416yellowz

no change in noise. And it has yella terra rockers, so valve train noise is really loud

dryadsdad

Let's hope then that the sender is bad. When will you know?

cclive

I would not assume that the sender is good...you need to get a real pressure reading before anything else. The sending unit is a weak point that many on the forum have had problems with, including me. My pressure went from normal to 130 to 0 when the sending unit was going bad.