I was driving my car last week and my oil pressure just dropped for no reason. I wasn't abusing it or even lugging it. I was actually driving normal. The engine only has 90,000 miles on it. I am pulling my engine soon to see what happened and I was wondering what I should pay close attention to. The car didn't overheat or start knocking. It lost power, but I think that was because the lifters weren't oiling properly. I am hoping this can be fixed for a reasonable amount of money. I appreciate any help or advice.

 

Verify the pressure with a mechanical gauge first.

Our sending units are notorious for failing.

 

Agreed. My factory guage always read really low. Hooked up a mechanical guage (in about 2 mins I might add) and it was actually much better than the factory guage showed.

 

The sending unit or the gauge is most likely bad. But my car did that and I had no oil pressure for like 6 months and I thought it was the sending unit but really the pickup tube on the oil pump had fell off into the oil pan. Might wanna get that checked ASAP.

 

The engine is losing oil pressure, at least in the top half. The sending unit is less than a year old. When the guage dropped, the lifters went to chattering. The pump was also put in less than a year ago. The pickup was tack welded and the driveshaft is an ARP. The car ran fine for about a year. The original engine suffered from a bad sending unit, so I have been through that already. This is a completely different engine, and a different sending unit and a different guage cluster and even the wiring to the c100 bulkhead connector are different. The sending unit is mounted behind the intake. I am wondering if something could keep the bottom half from oiling. I am going to hook a guage to the port above the oil filter and test there. what internal problem could cause this? The engine is full of oil( less than 2 weeks old ) and it smells fine. I am pulling the engine tomorrow and I was just wondering what I should pay special attention to.

 

before you completely rip out the engine take off your valve covers and make sure that the main drain holes arent clogged for whatever reason. And run a quart of automatic transmission fluid in it and let it idle for a little bit with that in there, then drain the oil.... dont drive it like that.

 

The drain holes aren't clogged, and there is no oil in the valve covers. I didn't get to pull the engine due to rain. I was wondering if a cam bearing could cause this. I read on the cz28.com forums that some people that installed hot cams in their engines had cam bearings fail. Would this cause this? I was going to pull my engine anyway because of painting. Now I actually have a reason. I appreciate all the comments and suggestions. I just don't understand how this could happen so suddenly.

 

If the drain holes arent clogged, and the little "squirt" holes in the lifters arent clogged then your pump aint workin. Time to get yourself a new pump I dont know what type of oil pump would be best for an LT1, not sure if the gen 1 engine oil pump design is the same as a gen 2 engine.

 

Yes they use the same pump. I have a melling M55HV in it now. I plan on replacing it when I pull the engine. I am going touse a M55 with a high pressure spring. What could cause it to fail like this?

 

i dont know man, my oil pump failed on me too, i took it all apart and i didnt notice anything that looked off from my melling M55 w/ M55-A (high volume) pickup and Mr. Gasket #26 (high) pressure spring...

The collar on the driveshaft didnt come out in pieces though, so that might have something to do with it, but i doubt it.

The most suggested oil pump combo is the one that I have, and I got it from the members of this board

Melling M55 Oil Pump
Melling M55-A Oil Pump Pickup (this is the high volume version)
Melling 55-SA Driveshaft (if i recall correctly atleast)
Mr. Gasket #26 Pressure Spring

Total for it was ~50 dollars when i bought it from Advanced Auto (they didnt have it on hand, had to wait like 4 days for them all to come in, but well worth it knowing i'll never have to bother with another oil pump again )

Got a exhaust shop to put one tac weld on there, done for free (thank *** hah).

I dont think your cam bearings could stop the flow to the upper end, but I guess it could also be possible... if all of your bearings in the cam where shot, and I mean ALL of them.

 

I will probably use that setup except with my ARP driveshaft. I thought I covered all the bases when I put my engine in. I guess I won't know anymore till I pull the engine. I will post my findings.

 

make sure your driveshaft has a metal collar, and not a plastic one, and a lightweight driveshaft helps too