Need Help - Oil pressure issue, new rebuild

Good Day 69 Coupe (73 block)
I have been asking many questions as I prepare to start my engine after 37 years.

Engine completely rebuilt. Assembled with plenty of assembly lube. Hooked up battery just to make sure it turns freely and new starter operational. Turns fine, but even though I have only cranked for max of 10 seconds on about 10 occasions, oil pressure needle doesn’t budge, at all. (new oil gauge, hooked up properly) I poured a small amount of oil in each cylinder every 2 or 3 times I cranked. Pulled oil pressure sending unit and no sign of oil in sender bottom port.

** I have a 73 block with the stock filter

I removed the oil filter and just a very little bit of oil was in the filter housing. Only the very lowest part of the filter was oil-soaked.

The oil pump is new. I did not do anything special to prime the oil pump when installed. The engine has only been assembled withing the last 2 months. Proper amount of oil in sump.

I do not want to continue cranking without some input as to anything I can do to verify all is proper. Was thinking of removing the filter housing and cranking to see if anything blows out of the ports, but that doesn’t sound real smart! Is there a method to assist in priming at this point? Other than rigging up gas to try and fire it up, all is double checked except this issue.

Murrieta, Ca.

Verify this before proceeding, but:
Isn’t the first place the oil arrives is at the OP relief valve? Could you not remove the OPRV and see if oil is being delivered there. Crank with spark plugs out of course.
Did you grease the oil pump rotors (aids in suction)? Check tip clearance and all that stuff on assembly?

David, yes, I did check all clearances, even though it was new, before installing. My problem with the relief valve is the round plate that the filter pushes up against is pressed into the housing and I can’t see any way of removing it. I can see the spring and part of the valve behind the plate but not sure how to access it?


Hi Mark…you could remove one of the gallery plugs on the side of the engine and useing a garden type sprayer pump some oil in…you should be able to get it up to the cams and pump through them

I’ve read the procedures for doing that, but I want to make sure that the pump is going to work properly. It’s my understanding that my block only has 2 ports, one from the pump and one that goes to the galleries. I was thinking of just trying to fill the port that leads to the pump and try to back fill it in that way,
I’m going to remove the housing and figure out how to get that flange of so I can access the relief valve.

I’ve got 4 years into putting this thing together correctly and I’m not about to fire it up without knowing for sure that I will have oil pressure.



You say that you have a 73 engine block, with a “stock” oil filter in your 1969 E-Type. If by “stock”, you mean stock for the 1973 engine (rather than stock for the 1969 E-Type), I can’t give much guidance. That said, I’d be somewhat surprised if the oil pressure relief valve is behind the round plate that the filter pushes up against. It’s not there in the 1969, for sure. The beehive style valve behind the plate in the 1969 is not the oil pressure relief valve. It is what jaguar call the “balance valve” and is there to allow oil to bypass the filter if it is clogged. The oil pressure relief valve (in a 69) is a removable one-piece valve than screws into the base of the filter housing. The earlier cars have a multi-piece valve that fits behind the outlet tube to the sump. Both a illustrated in the XKs Unlimited on line catalog. I won’t comment on whether removing the pressure relief valve to check if your pump is working is a good idea or not - I haven’t thought it through…

I never got oil pressure in only 10 seconds. Being extra cautious, pump oil into the galley plugs. Take out spark plugs, block throttle wide open, fully charged battery, crank 20 seconds at a time, then stop to let windings cool, battery on charger. After resting, crank again.

It used to take me 2 or 3 cycles to get pressure in a Spitfire and that is a tiny engine. It will go WHEEEEEEE…then…errrr as the oil fills the pump, you hear the engine slow down from the drag.

Just wondered this: will the gauge read pressure at all if the ignition is “off”? Are you just using the starter button? I don’t know the answer, I am better at coming up with questions. :slight_smile:

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My fresh rebuild takes 18 seconds of cranking(plugs out) to read pressure…7 more seconds gets me 25 psi…15 more seconds oils the upper timing chain and reaches a maximum of 40 psi(this last observation will not happen with your later engine). This is all after many weeks of sitting.

I’m going to go take a pic. Be back in a bit!

I am not surprised and you should not be concerned.

I started the rebuilt engine on my current resto for the first time last Wednesday. I first cranked it with the plugs out until the battery got tired; no oil pressure despite a couple of minutes.

I started the engine and hey presto! Good oil pressure in about 20 seconds.

Just start the engine. If you have no pressure after 30 seconds or so then shut it down, but I suspect you’ll be fine. If you are really concerned you could pressurise the system first by making an adapter to fit one of the oil gallery plugs and pumping oil through it until oil comes out of the cam feeder pipes ( loosen one of the olives and wait for oil to ooze out).

If your oiling system is properly assembled and ready to go, cranking it will get the pressure up…I used the O/P sender port at the filter canister and adapted a short hose and gauge to that port. Crank away…

I cranked the engine several more times and then pulled the sending unit (brand new) and saw oil in the port. I then had my wife crank the engine as I held a rag over the port. Oil shot out and a check of the cam via the filler cap show oil is reaching the cams. I now have to check the connections for my NEW Oil gauge to see if it’s working properly??

A little more cranking did eventually fill the galleries.

Thank you for all the comments. I admit I was a little reluctant to crank it over too much.


Good to hear it all well. Are you using a heavy ZDDP break in oil?

my digital gauge always measures 4psi while cranking, (and thats when it is already primed)

it runs ~50psi on start up

(Admittedly I havent cranked without starting for longer than 30secs)

I would be unsurprised if the OEM sender/gauge combo does not register pressure under 10psi

My V12 lost its prime after excessive sitting, scary business! At least I had the foresight to crank it over with the plugs out and bores lubed.

I used a Sealed Power engine preluber to get it back by pumping a couple of quarts through the oil pressure switch fitting at the top of the engine.

I’m wondering exactly how long does it take for this to happen with sitting V12’s.

I would use a mechanical oil pressure gauge to assure yourself what the actual oil pressure is!
The electronic senders are notoriously unreliable to give an accurate oil pressure reading. I have gone through three senders to find one remotely accurate.

I agree with Len. I observed my electric gauge slowly reducing the “measured” oil pressure. At start up I would see a running pressure around 40psig. As the oil warmed up it would drop to 25psig. Based on discussions on this site, I added some plumbing at the oil pressure sending unit port to allow me to install a mechanical gauge as well as the electric gauge. Now the cold pressure on the manual gauge reads around 60psig with the electric gauge reading about 40psig. At operating temperature, the mechanical gauge reads a bit over 50psig while the electric gauge is reading about 25psig. Don’t trust the electric gauge. I went through multiple sending units with no luck finding one that came close to matching the mechanical gauge. A last note regarding your concern regarding no pressure when cranking the engine. I’ve noticed the electric gauge takes longer to record the low pressure when cranking than the mechanical gauge. My mechanical gauge begins to move almost immediately. Another reason to have a mechanical gauge.

Thank you to all. I have a mechanical gauge, but was reluctant to install in the dash because of the extended plumbing and the fear of something leaking, etc. I put a new Smith in, instead. After all the discussion on this thread, I think I will install another mechanical on one of the gallery ports so I can verify, routinely. This is the first t t time I have taken a car down to nothing connected to anything else; body, engine, IRS, tranny, everything. The closer I get the more cautious I get. There are quite a few things that I have rebuilt and are sitting on my shelves, but at the last minute I decided to get new ones and save the old ones as spares.

I used one of those new telephone attachable scopes to look at the firewall end of the exhaust cam so I could verify oil being pumped in when it finally arrived.

I will end this by saying that in todays time, with all the changes that have taken place with oils, lubes, etc etc and all the after market options, I doubt I’d be where I am without the advice from forum members and previous threads that address just about every possible issue that could arrive. I have taken a lot of pics and will do a little montage when it starts and runs! It won’t be a concourse job, but my wife and I will enjoy taking it to all the local shows in So. Cal. We drove it 5000 miles in 1976 after we were married. Thru tornado weather in Kansas and all thru the east coast.

My wife had a 19 year old cousin in a small Missouri Valley town and all he wanted me to do was drive him downtown so he could wave at friends. We went thru all 3 stoplights! He didn’t even want to drive, just be seen in it!

Thanks again

Murrieta, Ca.


Mark this Tee piece might make it easier to hook up a mechanical gauge and keep electric gauge too. They sent me the p/n M-COP-4 copper crush washers to use with it too. All together including shipping from the UK to Houston cost about $25 (18 pounds). Got here in about a week. My plan is to just install mechanical gauge under the bonnet to keep tabs on how accurate the electric gauge is.

68 E-type FHC

Respectfully gentlemen, I never understood the logic for two gauges.

Why not have just one THAT WORKS and is in the car where you can SEE IT?
It’s not that hard to accomplish and it can look just like the flakey electric gauge that gives questionable information. Here’s one now: