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Discussion Starter #1
74 GTV with webers....did an engine rebuilt and don't see any oil pressure distributor spins my dash gauge worked before and now does not. I also did ground the oil pressure sender wire and the dash gauge went up to max. I even replaced the oil pump with a brand new one still the same. I also took the dummy red light oil sender switch off and cranked it and no oil coming out, so no oil pressure.

I am inside a garage with 40 degree temperature and using 30wt non-detergent oil, could it be the oil is on the thick side and the oil pump is not picking up?

I had cars parked outside before on a much lower temperature and the oil pressure was fine.

Any thought never had this issue before.

TIA
MK
 

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No pressure on the gauge or no actual pressure? If you take out the oil pressure sending unit above the starter, does oil come out?

The oil pump spins the distributor. That is, the gear that meshes with the crank is pinned to the oil pump shaft. A dog connects to the distributor. So if the distributor is spinning the oil pump is spinning. 30W should be fine in that temperature. There are a number of possible issues if in fact you have no oil pressure, but I'd check first whether it's a real problem or an indicator problem. To test the oil gauge, turn the car on, ground the wire from the sending unit to the body. Does the gauge go to max? If so, gauge works.

Andrew
 

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Question #1: It doesn't generate oil pressure with just the starter turning the engine, or it doesn't generate pressure while idling?

Sometimes after a rebuild the oil pump can be hard to get primed. I always pack my pump with white grease to make sure there is an airtight seal between the gears when it first starts up. After that, the internals of the pump stay oily enough to allow it to begin pumping quickly. So question #2: Did you disassemble the pump and reassemble it dry? Or install a new pump without oiling/greasing it? If "yes", then continued cranking may get it to prime.

Question #3: Did you work on the pressure relief valve? Might it be stuck open?
 

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Discussion Starter #4
Question #1: It doesn't generate oil pressure with just the starter turning the engine, or it doesn't generate pressure while idling?

At first I did not believe on the gauge reading cranked it and started the car for few seconds then it died starving for oil.

Sometimes after a rebuild the oil pump can be hard to get primed. I always pack my pump with white grease to make sure there is an airtight seal between the gears when it first starts up. After that, the internals of the pump stay oily enough to allow it to begin pumping quickly. So question #2: Did you disassemble the pump and reassemble it dry? Or install a new pump without oiling/greasing it? If "yes", then continued cranking may get it to prime.

I reinstalled a new pump yes without oiling it and cranked it many times still no oil pressure. I have rebuilt many engines and never had any oil pump issue, next time I will be very cautious.

Question #3: Did you work on the pressure relief valve? Might it be stuck open?
What is the pressure relief valve? I unscrewed the dummy red light switch and after cranking no oil is coming out, so still no pressure.
 

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Discussion Starter #5
No pressure on the gauge or no actual pressure? If you take out the oil pressure sending unit above the starter, does oil come out?

The oil pump spins the distributor. That is, the gear that meshes with the crank is pinned to the oil pump shaft. A dog connects to the distributor. So if the distributor is spinning the oil pump is spinning. 30W should be fine in that temperature. There are a number of possible issues if in fact you have no oil pressure, but I'd check first whether it's a real problem or an indicator problem. To test the oil gauge, turn the car on, ground the wire from the sending unit to the body. Does the gauge go to max? If so, gauge works.

Andrew
Yes seems it's a real problem not a switch issue, yes I did ground the wire and the needle went up all the way so the sender is good.
 

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So question #2: Did you disassemble the pump and reassemble it dry? Or install a new pump without oiling/greasing it? If "yes", then continued cranking may get it to prime.
Looks like 30wt oil (30 is the upper index, right?) makes it even harder...
 

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There are 2 common types of pump failure. Gradual pressure loss is most common, and usually involves other issues like bearing wear with metal in the pump that opens radial and axial clearances. The second type is sudden. Often caused by a broken main shaft, with 2L pumps, either at the cross pin through the crank driven gear (most common), or above the drive gear at the first step in the 2L reduced diameter shaft. This above the drive gear failure does NOT happen with earlier helical cut gear pumps with single diameter main shafts. The 2L shaft broken above the drive gear, at the step, alliws the distributor to continue to turn, the engine to continue to run with no oil circulation. As this is a sudden failure, unless it happens on cold start up (most common), you dont notice in time to avoid a blown engine.
Relief valve pistons usually stick closed, from spring pressure on shut down. They can stick open from debris in the oil, but this is less common.
A) Is there oil in the sump?
B) Has the filter seal blown out?
C) Are there signs of a massive oil leak anywhere?
D) Does the distributor turn?
E) Engine NOT running, starter only, with filter off or sender removed, can oil be pumped out of the sump?
After these questions are answered it's easier to diagnose.
My opinion only, from my experience building Alfa oil pumps, street and race, for my customers.
 

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Grounding the wire tells you the gauge is good, not the sender.
I'd still remove the sender, turn the engine over, and see if you get oil out that port.
Andrew
 

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Discussion Starter #11
Ok guys I think I have a clue of what might be causing this....the front cover gasket from centerline was quarter inch short on top on the oil filter side, so I used another gasket from a leftover gasket package and I believe the one that I used had blocked the oil passage and did not pay attention to it..... my mistake.
Now I will need to take the front cover out while the engine is in the car.

1- What is the easiest way to loosen the crank pulley nut without the engine turning? Keeping it on a gear.
 

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That WILL do it!
 
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