Oil pressure
#1
Oil pressure
I have an 85 which i recently swapped in a different short block due to #2 bearing failure on its original motor.
The oil pressure sender i got from the original motor and when i installed it the oil pressure gauge was pegged but the oil light worked. i drove it for around 200 miles and finally got around to installing a new sender. After install the gauge reads less than zero oil pressure all the time while running, but the oil light is not on.
When i changed out the sender oil poured out the hole and when i remove the filter oil comes out so the pump must be working and oil must be flowing to the bearings per oil flow diagram on clarks. Also there is no valve noise / lifter noise or anything.
I have also driven it a good 40 -50 miles since changing the sender and over so I have to assume that I have oil pressure.
Can a brand new sender fail so that it reads zero the whole time? I figure if I actually had zero oil pressure the motor would have let me know about it.
The oil pressure sender i got from the original motor and when i installed it the oil pressure gauge was pegged but the oil light worked. i drove it for around 200 miles and finally got around to installing a new sender. After install the gauge reads less than zero oil pressure all the time while running, but the oil light is not on.
When i changed out the sender oil poured out the hole and when i remove the filter oil comes out so the pump must be working and oil must be flowing to the bearings per oil flow diagram on clarks. Also there is no valve noise / lifter noise or anything.
I have also driven it a good 40 -50 miles since changing the sender and over so I have to assume that I have oil pressure.
Can a brand new sender fail so that it reads zero the whole time? I figure if I actually had zero oil pressure the motor would have let me know about it.
#2
Got Nothin'
Rennlist Member
Rennlist Member
A new part can be bad. Also may want to ensure that the Oil Pressure Relief Valve is properly aligned.
I just went through the same thing, in that the car had no oil pressure (indicated) after a rebuild.
After a ton of troubleshooting, the shop that provided the rebuilt short block discovered that the shop that actually did the re-assembly did not align the relief valve. It was jammed into the block and was binding. To be safe, the pulled the motor (again) and checked the main and rod bearings. Thankfully they were fine.
I now have great indicated oil pressure.
I just went through the same thing, in that the car had no oil pressure (indicated) after a rebuild.
After a ton of troubleshooting, the shop that provided the rebuilt short block discovered that the shop that actually did the re-assembly did not align the relief valve. It was jammed into the block and was binding. To be safe, the pulled the motor (again) and checked the main and rod bearings. Thankfully they were fine.
I now have great indicated oil pressure.
#3
Burning Brakes
Check the wires to make sure (A) they are not connected reverse (though i think this would actually show High Pressure) and (B) check to see that there is 12v and good ground..
p.s.
Sounds like your original sender was working fine; but the wires were simply connected backwards..
p.s.
Sounds like your original sender was working fine; but the wires were simply connected backwards..
#4
I drove it around 100 miles today and it didn't blow up and is running great. There is still no lifter noise at all.
Every now and again the gauge goes crazy. Flicks all over the place. I checked the wiring and it was knackered so I recovered it with electrical tape.
I also pulled the OPRV and it seems fine. I cleaned it up and put it back in to no effect.
Oil does come out of the filter when I remove it so the pump is working and it also comes out when I remove the sender so I should have at least some pressure registering. The gauge stays put at below zero all the time bar when it jumps around.
Im just gonna get a new sender and go from there i think.
Every now and again the gauge goes crazy. Flicks all over the place. I checked the wiring and it was knackered so I recovered it with electrical tape.
I also pulled the OPRV and it seems fine. I cleaned it up and put it back in to no effect.
Oil does come out of the filter when I remove it so the pump is working and it also comes out when I remove the sender so I should have at least some pressure registering. The gauge stays put at below zero all the time bar when it jumps around.
Im just gonna get a new sender and go from there i think.
#5
Rennlist Member
i believe there is an early and late sender- early and late dash. Make sure the wires arent somehow reversed and if not it may be the sender. Sure doesnt sound like an oil pressure issue.
#6
I assumed also the larger terminal would be for the gauge and the smaller for the idiot light - this is not the case though and didnt really make sense to me.
On my original sender both terminals are the same size.