where to start on motor with no oil pressure

tford

Registered Member
Joined
Nov 17, 2004
I have a 87 motor that lost oil pressure a couple years ago. Instead of throwing parts at it to figure out the problem and wasting time, I just got another motor. My ? is, how can I find out what the problem was with the engine out of the car. I was going to replace the oil pump. Do you guys think I should just completely tear it down & do a rebuild. This is the #'s matching engine with about 90k on it. Is there any way to inspect the oil pump to see if it is shot? I guess I can replace the oil pump and hand crank it with plugs out of course, and see if oil starts coming up to the top end, right? I'm learning little by little, so please explain if my questions seem stupid. I did not do any inspection of the motor, just tore it out and dropped another in. Please tell me what to start with. I'm tired of it sitting on the stand collecting dust. The motor did not knock, just lost oil pressure and I shut it down. Tim
 
check the oil pick up.. had one that was just hanging there. I had never seen something like that before..
 
If it were mine I would tear it down and rebuild. The cam will go in a hurry if it wasn't getting the oil it needed. That being said. I'd put it on the stand and start from the bottom and work my way up looking for the problem. It should be somewhat obvious when you find it. Especially if it lost it all at once. Loose pickup, bad pump, spun bearings, etc.
 
All you need is a second without oil to wipe out a bearing. I would pull the pan and check the bearings and pickup. Also take the cam sensor out to see if the oil pump drive broke.
 
Thanks guys. I'll drop the pan and see what I find. Before this happened, it started bucking & backfiring on light throttle if that helps diagnose it any better.
 
Don't worry with

Thanks guys. I'll drop the pan and see what I find. Before this happened, it started bucking & backfiring on light throttle if that helps diagnose it any better.

the pan. Start w/ the cam sensor. If it's broken, then the oil pump is the next stop.
 
The cam sensor goes into the front cover, right? For some reason I thought it was on the back close to the firewall. Also, do I need any special tool to remove it? Is there any procedure for removing or re-installing? Tim
 
Probably best to put it at TDC before you pull it out. A distributor wrench or socket with extension is all you need. When you put it back together, it's best to set the cam sensor.
 
Where are you located. You should really ask if someone who knows more than you can come by & take a look with you. Easy to take apart but not easy to assemble correctly!
Earl Brown has a good wirteup on front covers to start your reading.
Go to the other site under Tech & Articles in the sticky.
 
The front plugs next to the front cam bearing could have blown out. Happened to me on my rebuild.
 
Probably sheared the roll pin in the cam sensor. Why the pin sheared is the question, though. The oil pump may have injested debis which put too much load on the roll pin. If it started bucking, then definately a cam sensor issue. I would definately tear it apart and check everything. Pull the pan, check the bearings. Pull the timing cover and inspect the oil pump for debris/scoring. If there is alot of scoring, buy a new timing cover and be done with it. There are a few guys that will set up a timing cover so it is a bolt-on deal. With 90K it's probaly still in fair shape if the oil was changed frequently. GO with a roller cam and port the heads while you're at it. THAT will put a BIG smile on your face.
 
Any type of thick lube is just there to create a suction between the gears. if it didn't have that, it would just suck air past the gearing.
DON'T use too much! You could clog the filter top with it (after the oil starts flowing out of the pump and reduce oil flow that way..

I'd put the engine on a rotating stand and pull the distributor, make up a long rod/shaft that will go past the cam gear, but replace said distributor and connect that to a GOOD hand drill.

put about 1-2qts of diesel fuel in the oil pan to help clean gunk but not hurt lubricity (since it sat for a LONG time) Even try and fill the filter some, then re-install..

Start turning the pump with drill.. If you can go BOTH ways without resistance to one of them, your pickup might be separated from the pan rail.
If you start getting resistance (pumping) in a direction, keep it up until you can see oil coming from rockers and or gauge if attached.

If still nothing. pull the pan and inspect from pickup upward..

DO you remember how it acted back then before you shut it down?
Bucking?
Rough idle, but still ran?
high operating temp?
Just 'sounded' different?

Just my .02
E
 
Before I shut it down, nothing sounded out of the ordinary. Oil light just came on.
 
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