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Oil Pressure Help


Synestran

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Hey guys,

I've done a search on this forum as well as a general google to see if I can find some help with my problem.

I have a 1977 B210 with the A14 engine that I recently rebuilt. Started right up once everything was together and seemed to be working great until I noticed there was no oil getting to the top of the engine. Turned it off and have been trying to figure out why there is no oil pressure. I have hooked up an oil pressure gauge and it doesnt read any pressure at all. I've put a new oil pump on, new filter, checked the oil pickup tube, made sure there was actually oil in it, primed the oil pump, blew air through the oil pump and could here bubbles in the oil so I know that is clear. I have been having my friend who is a mechanic help me with this problem and we are both stumped. We made sure the oil pump is actually turning but it just isnt pulling the oil for some reason.

 

Any help would be greatly appreciated. If you need more info, I'd be more than happy to answer.

 

Thanks,

Syn

 

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Hey guys,

I've done a search on this forum as well as a general google to see if I can find some help with my problem.

I have a 1977 B210 with the A14 engine that I recently rebuilt. Started right up once everything was together and seemed to be working great until I noticed there was no oil getting to the top of the engine. Turned it off and have been trying to figure out why there is no oil pressure. I have hooked up an oil pressure gauge and it doesnt read any pressure at all. I've put a new oil pump on, new filter, checked the oil pickup tube, made sure there was actually oil in it, primed the oil pump, blew air through the oil pump and could here bubbles in the oil so I know that is clear. I have been having my friend who is a mechanic help me with this problem and we are both stumped. We made sure the oil pump is actually turning but it just isnt pulling the oil for some reason.

 

Any help would be greatly appreciated. If you need more info, I'd be more than happy to answer.

 

Thanks,

Syn

:lol:

 

It would seem that everything is OK. Even the old pump did the same thing. Assuming the pump is pumping oil, for a moment... if there was a large enough leak in the system pressure would not build. If rebuilt maybe it was hot tanked and the oil galleries unplugged and then not plugged?

 

 

 

Syn, take the oil filter off and start it up, (briefly of course) oil come out the hole?

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When you say hooked up a pressure gauge was this mechanical? If not what sender did you use? The stock sender doesn't work with all gauges. How did you originally determine no pressure (light on dash stayed on?)

 

No oil in the top end? I realize you said no pressure, period, but I wanted to make sure to eliminate a couple of things. First is the thinner head bolt in the proper hole? Also make sure it's the right lenght. It is possible to install a GX A12 bolt in the taller deck A14, it will tongue down but block the oil passage to the top end. Is this an A14 cylinder head or is it one of the earlier heads? (the oil hole from block to head is different) The early heads route the oil straight up from block deck to cylinder head where as the later ones the oil passage comes up though the bolt hole. You can also remove the rockers and pump oil down the passage to,see if it emerges down at the pump.

 

When putting together A-series engines I fill the oil filter pour the oil in motor and fire them up; a good pump doesn't have to be religiously primed. So it's odd you are having issues.

 

Make sure you have the right pick up tube and oil pan combo it is possible to have the pick up tube screen flat on the pan, it will pick up oil but you'll have drop of 35-40 psi, on a stock pump that will be 0 psi. If you,have a mighty vac hand pump see if you can pull oil up out of the pan. Check the gasket between the block and pick up tube and then check the tube, a small crack in the tube or the gasket not sealing well can lead to this.

 

When you say pump turning how did you check this? Pulled the cover? Also this is going to sound dumb but is this the stock cam? My thought is you could have an aftermarket cam for an A12 which will fit but as the drive gear is in a totally different location it won't spin the pump.

 

My thought on plugged oil galleries is this; the sender is on the pump, as you get no pressure at the sender, somewhere between the pick up and output of the pump you are losing pressure and or not building it. As the old pump doesn't work either my first stop is going to be the pick up side of the pump. Finally on the gasket between the pump and block are you installing the dry or using some kind of sealant. I use Yamabond (grey) or,something similar and use it very very sparingly, don't want bits of sealant stuck in a passage.

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Good catch. I have built many A motors and still didn't catch that one.

 

It would help to verify the oil pressure with a mechanical gauge mounted directly to the block. Don't use electrical gauges when verifying anything. You're assuming that they work.  I have a set of mechanical gauges that I use in the shop just for verifying.

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:lol:

 

It would seem that everything is OK. Even the old pump did the same thing. Assuming the pump is pumping oil, for a moment... if there was a large enough leak in the system pressure would not build. If rebuilt maybe it was hot tanked and the oil galleries unplugged and then not plugged?

 

 

 

Syn, take the oil filter off and start it up, (briefly of course) oil come out the hole?

 

I've taken the oil filter off and nothing happened.

I hooked up a mechanical gauge when testing for pressure and it didnt move at all.

 

I tore the engine down and reassembled it myself. It was hot tanked and I do not know if the oil galley plug things were taken out or not. The machine shop I took it to for cleaning didn't mention anything about it.

Oh, and I had put 3.5 quarts in it and was showing on the middle of the dip stick.

 

When you say hooked up a pressure gauge was this mechanical? If not what sender did you use? The stock sender doesn't work with all gauges. How did you originally determine no pressure (light on dash stayed on?)

 

No oil in the top end? I realize you said no pressure, period, but I wanted to make sure to eliminate a couple of things. First is the thinner head bolt in the proper hole? Also make sure it's the right lenght. It is possible to install a GX A12 bolt in the taller deck A14, it will tongue down but block the oil passage to the top end. Is this an A14 cylinder head or is it one of the earlier heads? (the oil hole from block to head is different) The early heads route the oil straight up from block deck to cylinder head where as the later ones the oil passage comes up though the bolt hole. You can also remove the rockers and pump oil down the passage to,see if it emerges down at the pump.

 

When putting together A-series engines I fill the oil filter pour the oil in motor and fire them up; a good pump doesn't have to be religiously primed. So it's odd you are having issues.

 

Make sure you have the right pick up tube and oil pan combo it is possible to have the pick up tube screen flat on the pan, it will pick up oil but you'll have drop of 35-40 psi, on a stock pump that will be 0 psi. If you,have a mighty vac hand pump see if you can pull oil up out of the pan. Check the gasket between the block and pick up tube and then check the tube, a small crack in the tube or the gasket not sealing well can lead to this.

 

When you say pump turning how did you check this? Pulled the cover? Also this is going to sound dumb but is this the stock cam? My thought is you could have an aftermarket cam for an A12 which will fit but as the drive gear is in a totally different location it won't spin the pump.

 

My thought on plugged oil galleries is this; the sender is on the pump, as you get no pressure at the sender, somewhere between the pick up and output of the pump you are losing pressure and or not building it. As the old pump doesn't work either my first stop is going to be the pick up side of the pump. Finally on the gasket between the pump and block are you installing the dry or using some kind of sealant. I use Yamabond (grey) or,something similar and use it very very sparingly, don't want bits of sealant stuck in a passage.

 

No pressure and nothing going to the top end.

I checked the pump by removing the cover and having my friend check to make sure it is turning.

As far as the cam, it should be the same one as I sent it off to make for a little better performance.

I dropped the oil pan (only could get a couple inches as I didn't take out the bar that is in the way) and see that it is still connected and secure.

I also filled up the oil filter so that when turning the gear on the oil pump, oil was coming out of the "out" hole. Even doing that, nothing showed up on the mechanical gauge.

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Any possibility you installed the crank main bearings upside down? Thus plugging the main oil gallery? I did that once and jacked up a brand new rebuilt engine.

 

I don't think I did. I had my mechanic friend help me to make sure I didn't do anything wrong. Doesn't mean we didnt, just dont think we did. We were really careful with the bearings.

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Oil from the pump goes through the filter and into a long gallery the length of the engine. From this gallery is a tube up past the oil pressure sender to the top of the block where it enters into the bottom of the head to lubricate the valve train. From the gallery are five tubes that supply oil down to the crank main bearings. From here the crank is cross drilled to take oil to the rod bearings

 

 

If the crank main bearings are blocked the crank would starve for oil but you would have oil pressure in the main gallery still and to the head. At the very front of the block is an oil feed to the timing chain tensioner and an oil jet for the chain... these would also be unaffected.

 

If you had zero oil pressure it was from something other than the mains in backwards.

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I still think you have a pickup problem; you put the old pump and nothing, I am assuming you had oil pressure before you rebuilt the motor or you wouldn't be asking these questions.

 

If we go step by step:

 

first pull off the pump, I have a mighty vac and would stick the rubber fitting in the block and see if I could vacuum oil up out of the pan.

 

If you cannot then the next step is to see if the block passage is plugged,

 

If it isn't then find the right size hose and thread through the block passage into the pick up tube, if it then pulls oil it's the pick up tube gasket,

 

If not there is a crack in the pick up tube or the screen is partially blocked.

 

If you wish to pull the pan put a jack under the bellhuosing and undo the motor mounts that will allow you to raise the motor just enough to slide the pan past the cross member.

 

As for testing the output, get a 2 ft length of hose the same diameter as the hole in the block that goes to the oil gallery (pump output), stick one end of the hose in the block hook the other to a funnel. Hold the funnel above the cylinder head then fill it with oil. Oil should drain out of the funnel and ooze out of various passages.

 

If this is a bit to hillbilly, you could also fabricate a simple blocking plate with fittings for the pick up and output holes, you could bolt it to the block and test. You could use a pressurized mini oil tank or syringe to check flow through the engine as well as use this to see if oil pick is the issue.

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Take a look at the distributor rotor while spinning the motor.  If it is spinning, the gear on the cam is good.  Since the dist and the OP DO NOT share  a common gear as the L series do,   Mark the dist and pull it out, spin the motor again to see IF the OP gear is spinning.  You may have sheared the OP gear off its drive shaft.

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First questions - Oil pump. Did the pump work before? Is it a new pump? Did someone have it apart to clean or rebuild it?

 

Second question - Upon engine assembly, did you pack assembly lube in the oil pump ports? This helps create suction on a completely dry system. It's not a deal breaker.

 

Third question - Did you or did you not install oil galley plugs? Almost every time you send a block to a machine shop, they remove the galley plugs prior to cleaning the block. Sometimes they leave them out assuming the customer will put new ones in. There's one in the front of the block, behind the timing gear and one at the back of the block behind the flywheel. If they were left out, oil should be spilling out of your bellhousing. If for some reason, the rear one was installed, but not the front, the oil will shoot out behind the timing gear on the cam.

 

I just went through this on a Jeep 232 straight six. Turns out that someone put the oil pump together incorrectly and the bypass valve had a leak.

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He did say he put the old one back in and still nothing.

 

 

If an oil gallery plug was removed then you would still get oil supplied to the oil filter. Oil pump sucks oil out of pan sends through the filter to the oil gallery. If a plug is missing, oil just dumps out and drains back to the pan and it won't build any pressure but it should still be passing oil through the filter.

 

I've taken the oil filter off and nothing happened.

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I still think you have a pickup problem; you put the old pump and nothing, I am assuming you had oil pressure before you rebuilt the motor or you wouldn't be asking these questions.

 

If we go step by step:

 

first pull off the pump, I have a mighty vac and would stick the rubber fitting in the block and see if I could vacuum oil up out of the pan.

 

If you cannot then the next step is to see if the block passage is plugged,

 

If it isn't then find the right size hose and thread through the block passage into the pick up tube, if it then pulls oil it's the pick up tube gasket,

 

If not there is a crack in the pick up tube or the screen is partially blocked.

 

If you wish to pull the pan put a jack under the bellhuosing and undo the motor mounts that will allow you to raise the motor just enough to slide the pan past the cross member.

 

As for testing the output, get a 2 ft length of hose the same diameter as the hole in the block that goes to the oil gallery (pump output), stick one end of the hose in the block hook the other to a funnel. Hold the funnel above the cylinder head then fill it with oil. Oil should drain out of the funnel and ooze out of various passages.

 

If this is a bit to hillbilly, you could also fabricate a simple blocking plate with fittings for the pick up and output holes, you could bolt it to the block and test. You could use a pressurized mini oil tank or syringe to check flow through the engine as well as use this to see if oil pick is the issue.

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Just got back from camping the last couple of days, I've been thinking it is probably something with the pickup tube or gasket allowing air to get in and not providing the suction needed.

I'll see if I can pull the pan off so I can take a good look at it.

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Pulled the pan down (couldnt squeeze it off complete as it hit the sway bar(?) or the cross member) and was able to take off the pick up tube. It was definitely tight enough on there. I did notice that when I took it off, only a little bit of oil was still on the screen. It has been sitting for a little bit but didnt seem like the oil was up to the intake part? I put in 3.5 quarts and showed the middle of the dip stick. Would the extra .5 quarts of oil be enough for the oil level to not be able to reach the pick up?

Gasket on the tube was good. Thinking maybe I just needed some more oil at this point?

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The oil pick up should be almost at the lowest part of the oil pan. Sitting level a quart should be enough to cover it.

 

Years ago I had a V8 engine I took out to rebuild but ended up selling. The pan was off but the pick up still on the block. The new owner had it rebuilt but oil pressure was not good and the hydraulic lifters clicked. A couple of weeks later it threw a rod. To this day I bet the block fell over on the pick up tube and bent it or the block was mishandled and it was bent. Sucking air and some oil.

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