No oil pressure after engine install

[saewoody]

OK, I got my engine started today after having it out to do the timing chains.

Now I have no oil pressure. I don't think there was any debris left in the engine from the plastic guides. I replaced the oil pickup tube, but reused the gasket because no one around here had it (I assumed it would come with the oil pickup tube-that seemed like a very logical thought to me; but it didn't) and I just wanted to get the engine back together and didn't want to wait 2-3 days for a gasket.

My brother works with a mechanic who used to work at a Ford dealership. He actually asked if I replaced the gasket with the pickup tube as his first question.

Does this make sense? Could a reused gasket cause enough of a problem that my gauge would be reading just about zero oil pressure? I can't imagine my oil pump all of a sudden failed.

Please let me know what you think. I've spent too long on this project. I need to mow my lawn!

As always, thanks in advance for your input.

 

[naterob1]

Since you had the oil pump assembly apart you lost all oil in the pump. You needed to prime the oil pump. I almost made that mistake when I replaced mine with a reman. In the Hanes manual under "prime oil pump" the first step is "remove engine". Sorry.

 

[2000StreetRod]

Oil pickup tube gasket

I also reused my oil pickup tube gasket. I just put some gasket sealer on it for reassembly. I primed the oil pump before reassembling the engine. When you rotate the engine with no oil in the pan the oil pump will force out the oil and replace it with air. When it gets full of air it may not suck the oil from the pan after you add oil.

Did you remove the intermediate shaft between the oil pump and the drive gear?

Did you prefill the oil filter with oil?

How long did you run the engine?

There are ways to prime the pump without pulling the engine.

 

[JDraper]

Just a couple of dumb questions....How are you measuring oil pressure? Factory faux gauge or a real oil pressure gauge? Is the sending unit hooked up?

 

[2000StreetRod]

externally priming oil pump

Note: I have not attempted either method I've described below but they seem reasonable and should work.

Engine oil flow is as follows:

oil pan > pickup tube > oil pump > oil filter adapter > filter

To prime the pump you need to force oil into the pump inlet or outlet.

To use the oil pump inlet:
1. drain oil from pan
2. remove the oil filter
3. remove the oil pan
4. remove the oil pickup tube
5. friction fit a hose into pump inlet
6. connect the hose to a hand pump
7. fill the hand pump with oil
8. force oil into the engine oil pump until it flows out of the oil filter adapter
9. prefill oil filter with oil and install
10. disconnect hose and hand pump
11. install oil pickup tube (use gasket sealer if reusing gasket)
12. install oil pan
13. add oil to pan

To use the oil pump outlet:
1. purchase a spin-on remote oil filter adapter (available from O'Reilly and other auto parts stores for less than $20) and a hose barb brass fitting)
2. remove oil filter
3. install brass fitting into adapter port marked "out"
4. connect oil hand pump hose to brass fitting barb
5. fill hand pump with oil
6. force 1 quart of oil into adapter
7. disconnect hand pump from adapter
8. remove adapter
9. prefill oil filter with oil and install

It is still possible to spin the oil pump by connecting a drill to the intermediate shaft. However, the shaft access cover is at the rear of the engine under the upper intake manifold. Ranger7ltr did this before starting his rebuilt engine and posted a thread about it. I believe removal of the upper intake manifold is required and a female hex bit is needed to mate with the intermediate shaft. The hex bit must be securely attached to the drill or there is the possibility it will remain attached to the intermediate shaft when the drill is removed.

The photo below shows the location of the access to the intermediate shaft drive gear.

The green arrow identifies the drive gear access cover and the red arrow identifies the cover retaining bolt. The engine was mounted on an engine stand when the photo was taken.

 

[saewoody]

Just a couple of dumb questions....How are you measuring oil pressure? Factory faux gauge or a real oil pressure gauge? Is the sending unit hooked up?

Using the factory guage in the dash. the unit is hooked up. It rises just a bit, but barely.

 

[saewoody]

I also reused my oil pickup tube gasket. I just put some gasket sealer on it for reassembly. I primed the oil pump before reassembling the engine. When you rotate the engine with no oil in the pan the oil pump will force out the oil and replace it with air. When it gets full of air it may not suck the oil from the pan after you add oil.

Did you remove the intermediate shaft between the oil pump and the drive gear?

Did you prefill the oil filter with oil?

How long did you run the engine?

There are ways to prime the pump without pulling the engine.

Well, I did not prime the oil pump. That was a major thing to overlook. I did not remove the intermediat shaft. I did not prefill the filter (I never have; it seems like a good idea; I've had horizontal filters on past cars). The engine ran for probably four minutes before the guage caught my eye. It was not making any odd noises. I had oiled the camshaft assemblies before the valve covers went back on. I will try one of your methods; hopefully today.

Thank you everyone for your input. I didn't want to pull the engine again.

 

[my98nnj]

Using the factory guage in the dash. the unit is hooked up. It rises just a bit, but barely.

The engine ran for probably four minutes before the guage caught my eye. It was not making any odd noises.

I don't think oil pressure is your problem. You would definately hear a very dry sounding engine if you had no oil pressure, especially after 4 munutes.

I suspect your real issue is with the idiot gauge as it's really only a switch, not an actual gauge. Being you see it rise only a bit tells me something is wrong with gauge, not your engine. The sending unit signal is either ON or OFF, so the needle should be either up where it always stays or down right where it sits when the engine is off. There's no middle, no indication of any pressure changes, just ON or OFF.

Put a real oil pressure gauge on the motor and I'm pretty sure you'll see ample oil pressure. Then trouble shoot the low oil pressure circuit.

 

[2000StreetRod]

bad switch connection

I don't think oil pressure is your problem. You would definately hear a very dry sounding engine if you had no oil pressure, especially after 4 munutes..

I agree. After 4 minutes with no oil pressure you would hear valve lash adjuster clatter.

I suspect your real issue is with the idiot gauge as it's really only a switch, not an actual gauge. Being you see it rise only a bit tells me something is wrong with gauge, not your engine. The sending unit signal is either ON or OFF, so the needle should be either up where it always stays or down right where it sits when the engine is off. There's no middle, no indication of any pressure changes, just ON or OFF.

Something may have lodged in the oil pressure switch port or there may be a poor electrical connection. Unfortunately, there is no easy way to install an oil pressure gauge. The only port I'm aware of is the oil pressure switch port which is very difficult to access even with the left wheel and inner liner removed. Click on the following link for info on how I installed my oil pressure sender. With a temporary mechanical gauge you would only have to remove the switch and then screw in the gauge tube fitting (with reducer) to verify good pressure.

Oil pressure gauge

 

[saewoody]

Thanks again for more input. I don't know if this makes any difference, but does anyone know if there was a bad electrical connection, if the "check gauge" light would or would not come on? In my case it came on. I've only ever seen it come on for low fuel. I think I have about a quarter tank (on flat ground) so I would think it has something to do with the oil pressure gauge. I'm going to check the electrical connection now. I had to mow the lawn before my wife nicely suggests that the lawn needs to be mowed.

 

[saewoody]

downfall of taping over an electrical connection

First of all I can't thank you all enough. JDraper wins the prize. I had been over that engine bay several times to make sure everything was hooked up; including about an hour to find the missing match to my last vacuum line. I would have bet you all $100 each that everything was connected.

I had taped over the connections and labeled them, but I must have lost them once I installed the A/C/power steering assemblies. Had it not been for StreetRod's link to how to hook up a true gauge I may have spent the afternoon under the truck.

Instead she's up and running. Sounds great!

Thanks for helping me out. It is much appreciated.

 

[2000StreetRod]

Congratulations!

Congratulations on repairing your timing chain problems yourself and having a quiet starting and running engine! I hope that your vehicle gives you reliable service for many years.

 

[JDraper]

Glad you found the problem without tearing the engine back apart again.

 

[saewoody]

Thanks for everyone's help! I've put about 125 miles on her so far and things are good.

Streetrod, thank you for your multitude of links and write-ups throughout this process. I know that I am not the only one who has benefited from them. Please keep up the excellent work. It is much appreciated.