Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing No oil pressure - help required

Group, please forgive me. I am overlong as I do not write for professionals. I deal with them but in a different way. I write for amateur Morgan owners like me and you.

As for why these things occur, Jeremy, I have no clue. Mechanics can be whimsical. Over the years, I see the pressure relief valve sticking most often with storage. All things mechanical run more reliably with frequent usage. On the other hand, I find the loss of prime happens most with oil changes mostly when non-Morgan mechanics change the oil ignoring the correct sequence our engines deeply require because of their oiling system.

And Jeremy, FWIW yours is not the game plan I would use though you are ultimately the boss. It is very conservative. I have done both priming and the relief valve many times. Priming is always when I am swapping engines, which I used to do more than I changed my socks. And I have non-invasively (shown below) modified the oil pressure valve system on all my Plus 8s which requires its removal. Of course I have also done both many times by proxy. 95% of Plus 8s (1967-2000UK) are identical in this area to yours.

Luddite, check these simple instrtctions below please. I like taking advantage of your presence. Two aging minds are better than one.

THE PRESSURE RELIEF VALVE

1. First and foremost, I cannot think of a way any intervention of yours can damage anything. That is for your assurance. The worst that can happen is you can negligently drop & lose forever a slippery component. Many of these are spring loaded, heavily oiled and gravity works in a drop's favour. Just be prepared. You also have the thimble shown on GoMoG, not one of the later ones. Keep it. All the internals for the pressure relief system are still sold inexpensively, either separately or as a kit...so losing anything will merely slow you down their delivery time. If you lose something, you can google it. The prices range more than 1000% for the same thing.

3. If the thimble does not pop out, it is stuck. Fish it out with a tool or a threaded long-enough bolt that fits into it and gives you enough purchase to convince it to leave its cozy home.I once had a owner merely add another "thimble" which increased oil pressure intolerably. Trust me, whether it pops out (as it should) or sticks (as is also likely at the moment), it is there.

4. If it was stuck, clean it and reassemble, you could be good to go after running the car a bit with dizzy disconnected without packing the oil pump with vaseline. After 30-60 seconds of that, receo0nnect the ignition and start her up. Always monitor from the driver's seat with your eyes on the oil pressure gauge. If you are mildly lucky, you will see no pressure at the gauge at first but then it will suddenly rise within 15-45 seconds. You see there is a reasonable hope that the pump will re-prime itself without vaseline.[/b] . If it doens't, stop turning the engine and pack the pump.

If you are lucky that entire fix will take 20 minutes..though us amateurs always take much longer the first time..which is NOT a bad thing. We are not on a professional's time clock, a BIG plus. Not packing the pump will save you an hour and be far less messy.

The only reason, at this stage, to remove the pump is to repair the inevitable wear on it. https://www.gomog.com/allmorgan/oilpumpbase.html. At the moment, yours is the one on the left. https://www.gomog.com/allmorgan/oilpumpbase.html That is not grave, just not great for oil pressure. 90% of all this V8's pumps are like that. But we should be happy, the later GEMS and Motronic (not used in Plus 8s) oil systems require the entire timing cover to be changed!!

Lorne

P.S. I would buy a new pressure relief valve spring along with the pump gasket just in case. I use a copper crush washer on the plug.
P/P/S I am very familiar with all this. I rely primarily on British V8 community lore. US lore of old can be ingenious but it is VERY old. With the UK tadpoles rather than the thimbles, I use a cute thingie from an performance Buick 215 supplier. It allows me to adjust my oil pressure with an Allen key on the road. ; )

As I typed from the outset, I am no expert and fortunately have never been required to get physically involved in the disassembly of any Rover V8 oil pump, other than to replace a failed oil pressure switch which controlled the electrical supply to the fuel pump relay as a safety circuit.

Given the above, I lack the anything like the amount of knowledge you have amassed on this and many other Morgan related issues Lorne.

I typed that I had doubts re the PRV causing the issue and detailed the reason behind that line of thought, I look forward to being proven wrong... and not for the first time... (-:

Using an oil can to prime the system via the removed oil pressure sensor`s orifice, and using the oil pressure gauge to provide some measure of success or otherwise before spinning the engine over, would be my go-to method... Tried and tested and proven on two of my own engines that did not build oil pressure after aspects of engine overhaul..

Whether there might be access or not on a Y2K +8, to work with an oil can as suggested, I have no idea..

As I have already typed, I care not which method Jeremy might care to make use of, I just look forward to reading that he is up and running with no issues...

Update: All parts ordered, including tadpole & spring from JED.
Hope to have a go on the PRV before the weekend.
Thanks again for all the help and support.

I like that very much.You have an uncanny understanding of mechanics that ignores silliness and goes right to the heart of the matter. Jeremy could do it by using one of those plastic syringes we all should have. https://shorturl.at/C28H5 Of course, we all take what gifts we have for granted.

For example, how LR mechanics do it is through the distributor hole. They remove the distributor and make or buy a female adapter https://rimmerbros.com/Item--i-RX1431L and use it (turning clockwise) with a variable speed drill to twirl the shaft that the distributor, camshaft and oil pump gear is all connected to. I use that method but yours is more intuitive and less invasive. I don't like the twirl the shaft method for amateurs as it has a domino effect that requires the removal and re-install of the dizzy..which can lead to other, delicate tasks. Your way avoids that and is much less messy. I am going to use it from now on and beware, I am adding it to GoMoG.

You have saved the owners of Plus 8s from 1968 to 2000 a mess.

Lorne

I am the only person who I know of may have used the oil can technique, and NOT on a Morgan, on an A Series BMC engine after removing the oil pressure release valve "bullet" and injecting oil into the oil galleries using a pump action oil can, through the relief valve orifice..

Similarly via the release valve orifice on the 2 litre twin Volvo diesel engine fitted to the sailboat I once owned...

Given the reported issues on the Rover V8, it would seem removing the pressure sensor may just be the simplest option...IF... access for the oil can or syringe does not create access issues...?

If removing the oil pump to grease up the gears, then if possible (access again..?) perhaps ensure the oil filter is full of oil prior to refitting the pump...?

Lorne I would not post this up on GoMoG until someone has tried and proved it on their Morgan... Even though I have no doubt it will work if it is only oil pump priming that has been lost, after that then fingers crossed and go for the pressure release valve stuck opened... After that... if in no way related to the pressure gauge...Ouch..!

Agreed. I thought you meant you had tried it on your Morgan...twice. The world must wait until we find a soul who has lost their Rover V8 oil pump prime.

I agree with you, I think it would work and I cannot see any potential harm to it. One is merely filling the oil pump with oil before putting the valve back in. (shrug) As I am suggesting Jeremy give the car a go after dealing with the pressure valve only.....why not?Certainly less of a hassle than Vaseline.

That is the thing I have discovered with Factory Workshop Manuals. They are written before ANY of the following 60 years experience with the engine.

L.

I used to prime the oil pump on a Rover 3.5 that a previous owner had installed in a SIII LWB Land Rover in a similar fashion George.
The oil filter had to be remote from the engine otherwise it would foul the front axle on a Land Rover. For some reason when the conversion was done they mounted the remote oil filter high on an inner wing. If parked up for a few weeks (I was away a lot in those days) it would drain back through the pump to the sump. I used to prime the pump by squirting oil from the oil filter housing connection back to the pump. Worked every time.

Graham, thanks for that info. As they say nothing is new under the sun and I suspect anyone with a practical mindset would arrive at some system or other to resolve that which seems to be a simple issue, all be it with potentially inconvenient if not mechanically damaging outcomes...It sure is not rocket science, were it so, I would have failed miserably...!

My use of a lever action oil can introduced a measure of pressure as could be witnessed on the gauge, which was comforting. I suspect there is no real need to introduce any pressure as such, just that the pump requires to be primed, thus gravity a syringe or any other method of getting oil back into the gears of the pump to restore it`s pumping capability is all that may be required... ?

I like that Graham. It won't work on a Morgan or other of these V8s as gravity works against it unless there has been a similar modification. But you and Luddite both grasped the whole point of priming, namely fill the ^*&$*% pump. It illustrates the point I tried to make on Factory Manuals..even those like Haynes. These Manuals are written by admittedly very expert people but BEFORE there is as much experience with the vehicle in question. Good forums, albeit with amateurs, mix many decades of hands-on reality. Better. The trick is to find a method that matches the expertise of the subject. That is what I like about Luddite's method. Harmless and non-messy.

A very collegiate debate. My compliments.

L.

In the off chance it might help, Halfords in the UK have a Laser brand oil can with a flexible nozzle available for circa £6.