Thread: No oil pressure

Just finished putting my motor back together. I replaced the head gasket, threw in ARP's and did a new timing belt. I figured while everything was apart I'd replace the oil pump gasket since I was getting a small leak from that area.

I pulled the pump with the rear balance shaft still attached. I replaced the front case gasket and the front balance shaft seal, along with the crank seal. I didn't take the rear shaft out just because I didn't want to mess with it. Put everything back together with all new gaskets.

I primed the car with the injector plugs unplugged. Went ahead and started it and noticed the oil light was on and the gauge was reading nothing. Checked the valve cover and no oil is getting to the head. The oil sender unit plug thing is connected as it should be, but it looks like the previous owner tapped into the line, but I don't think that would be causing zero oil pressure.

I had perfect oil pressure before I pulled everything apart. I know that the oil pump is just a set of gears, so I don't see how removing/re-installing could all of the sudden make the pump fail.

Any ideas? I know you need to prime a new pump when you install it, should I have to prime mine if I just removed/reinstalled? The car was running for about a minute with no oil pressure, I assume that would have been enough time for pressure to build up....

Maybe the gasket isn't sitting quite right?

Any suggestions would be appreciated :?

Did you connect the oil pump sending unit's wire back on? That's a direct wire to your gauge cluster and will read "0" if not connected.

Originally Posted by my3awds

Did you connect the oil pump sending unit's wire back on? That's a direct wire to your gauge cluster and will read "0" if not connected.

I checked that. I know for a fact that oil isn't getting to the head because I pulled the oil plug (where 1g's use for the turbo feed) and zero oil came out. I can also see (and hear!) in the valve cover that oil isn't getting to the valvetrain.

Could a bad sending unit itself cause zero oil pressure? Maybe a bad connection would cause no oil pressure? Any way to easily check that?

For some reason could oil be circulating everywhere else just not getting to the head?

Did you pull apart the oil pump assembly? If so, did you double check to make sure the teeth lined up to its timing mark on the inside of the pump?

Originally Posted by my3awds

Did you pull apart the oil pump assembly? If so, did you double check to make sure the teeth lined up to its timing mark on the inside of the pump?

Nope, I left the entire pump and rear balance shaft assembly together in one piece, didn't pull it apart at all. The only thing I did was remove the pump (with rear shaft still intact), scrap off the old gasket, install a new one and bolted it back on.

When I did the timing I didn't do the "inserted screwdriver" method, I did the easy "if it falls away from the mark its out of time, if it turns towards it its in time" method.....I should still have pressure tho, even if it was 180 off.

Thanks for the help so far. I'm hoping its something stupid and I don't have to pull the front case off again :?

Did you remove the oil pump pickup? Sometimes, people use RTV or misalign the gasket that goes between this and the oil pump, blocking any oil from entering. If you're dropping the pan, you could also check the condition of the pickup filter, to ensure nothing is majorly blocking it.

Remove the oil filter and see if you are getting any oil to that point. If no the pomp has a airlock in it :( . If so this works better with two people leave the filter loose and have the other person start the car. It should take no longer than a couple sec. to brake the airlock as soon as you get oil shut it down and tigthen the filter back down. and restart it.

Fingers crossed, I had a big pontiac do it years ago.

Originally Posted by my3awds

Did you remove the oil pump pickup? Sometimes, people use RTV or misalign the gasket that goes between this and the oil pump, blocking any oil from entering. If you're dropping the pan, you could also check the condition of the pickup filter, to ensure nothing is majorly blocking it.

Hmmmm

Yes, I did replace that gasket, no RTV though. I'm pretty positive I got the gasket in right... Thats a pretty easy fix, I'll definitely check that first. The pickup looked good when I pulled it the first time and my oil pan isn't dented enough to be pushing up against it. Wouldn't I still get at least some oil pressure? I seriously have zero, there isn't anything getting to the head at all...

Originally Posted by tqmx1

Remove the oil filter and see if you are getting any oil to that point. If no the pomp has a airlock in it :( . If so this works better with two people leave the filter loose and have the other person start the car. It should take no longer than a couple sec. to brake the airlock as soon as you get oil shut it down and tigthen the filter back down. and restart it.

Fingers crossed, I had a big pontiac do it years ago.

I actually left the car running for probably a min or so with the oil light on and the gauge reading zero. Wouldn't that have been enough time for any air that might have been in there to be pumped out?

Originally Posted by dsmguy142

I actually left the car running for probably a min or so with the oil light on and the gauge reading zero. Wouldn't that have been enough time for any air that might have been in there to be pumped out?

What you are trying to do is relive the air lock in the pump. With the filter still on there is no way for the lock to be relived.