Lost oil pressure while driving, ideas?

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slimjim

slimjim

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So I was cruising on the hwy at about 60 mi/h when I noticed the engine pitch start to change. I immediately looked at my gauges and noticed that my oil pressure dropped from 30 psi to 0. My temp was still the same. I pulled over, popped the hood and checked the oil. Still full and clean as far as I can see. Looked around the engine bay and underneath yet, no signs of any oil. I even checked the gauge sending unit and everything looks clean. Now this engine only has 100 miles on it. Everything is brand new. HV oil pump as well. What could cause this? My only thought would be that something clogged the pump and/or filter. I currently on the side of the road so I'll changed the oil tomorrow when I finally get home
 
30 psi at cruising already seems low. Maybe the pickup tube was loose and fell off. Just a wild guess.
 
Check the pump drive. That is, pull out the intermediate gear / shaft. Look for signs "the pin" sheared and it's slipping, or of course broken.

GAUGE....this mechanical, electric, what!? CHECK it

OIL....Mechanical fuel pump? Suspect fuel dilution

FILTER....stranger things have happened.

You have a priming shaft? See if you can "feel" anything from that. Should quite hard to turn, noticable by hand, and should "load down" a drill. Small block turns clockwise!!

Was the pressure always this low? 30 is REAL low for a new or good engine with a HV pump
 
If you have a small block you may have had a push rod go through a rocker arm and then the lifter came out of the bore. This results in zero oil pressure, remove the valve covers and look at the rockers. There is a tool that will let you go through the hole in the heads and grab the lifter and reinsert it into the lifter bore. Hope that this helps
 
superchargeddrt said:
If you have a small block you may have had a push rod go through a rocker arm and then the lifter came out of the bore. This results in zero oil pressure, remove the valve covers and look at the rockers. There is a tool that will let you go through the hole in the heads and grab the lifter and reinsert it into the lifter bore. Hope that this helps
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exactly happened to me once...but I was unlucky as a cam lobe wore down.....
 
terzmo said:
exactly happened to me once...but I was unlucky as a cam lobe wore down.....
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That really sucks. I had it happen to me twice and I was lucky twice. I didn't want to tempt fate so I installed the roller valve train and I haven't had any issues since.
 
I was told 10psi per 1000 rpm was acceptable. It's got a mechanical gauge. It's a hydraulic roller( roller cam, lifters, rockers)
 
high volume pump you say ?

stock volume pan?

not stirring the pot here but that might be part of the equation



I would slap on a priming rod and see if you can get pressure with that now that the car had time to rest
 
Did you hear the lifters collapse and start ticking?
 
Whatever you do, do not be tempted to start her up to see if it faith-healed itself.The urge is strong. Fight it.
Lots of good ideas here.And I would just like to add; Remember that little oil gallery screw-in plug, at the back of the engine? Accessible only from inside the bellhouse? And only after the outer access plug is removed? You can prove its in there while priming the oilpump.At the same time you can check the pump drive, and the drive gear on the back of the cam. Steel cams require that gear to not be oem or oem compatible. They need a bronze gear IIRC.I kinda think this is where the problem lies.
Sudden total loss of oil pressure almost has to be drive gear related.
 
Ok I have the bronze gear. I'm going to pop off the valve covers and the oil pan as well to see if any of the above suggestions could be the problem. It is a HV pump in a standard size pan. If I don't find anything there then I'll try to prime the pump and see if I can get anything. Thanks for the ideas. Hopefully I get lucky.
 
You could have broken the oil pressure relief spring in the oil pump also.

But the easiest thing to check is the pull the distributor and then the drive gear to make sure the shaft isn't broken.
 
slimjim said:
Ok I have the bronze gear. I'm going to pop off the valve covers and the oil pan as well to see if any of the above suggestions could be the problem. It is a HV pump in a standard size pan. If I don't find anything there then I'll try to prime the pump and see if I can get anything. Thanks for the ideas. Hopefully I get lucky.
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considering the cost and hassle of reinstalling the oil pan compared to reinstalling the distributor I would pull the distributor FIRST
 
Exactly, once a valve cover is off, you don't need them both yet, pull the distributor and make sure about the intermediate? shaft to the oil pump is ok, then spin to make sure that the pump itself is working. Whatever you do, make a plan and stick to it. You don't want to try to many things at once. The important thing is to check to see if the pump itself is bad. And by pulling the distributor you can see if that shaft is good.
 
10-20 lbs pressure at hot/idle is plenty with reg oil pump. as long as she climbs with rpm and holds at rpm... you are good...
 
almost forgot, did you build the engine or did you have it build?
if you had it build I wouldn't even bother looking into things myself, I would be talking to the person who did the work and see what his idea of warrantee is
 
Yeah unfortunately I built it so it's all on me. I drained the oil and popped off the valve covers. Oil had some shavings but I expected that from a brand new build. The valvetrain looks great. I'm going to pull the dizzy off now and try to prime it.
 
Hmm... Found it. Is there another issue that caused this or is this most likely dumb luck? Shaft is brand new.
 

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I'm taking a break from it today. Im going to try and put some jb weld on the end of a rod and then adhere it to the broken piece
 
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