Oil Warning light on !

[Biffdiff42]

Hi

I have just removed the sump and cleaned it out, along with the oil pick up and put it all back together on my Rover V8 SD1 roughly 1978 and filled it with oil, and there is plenty on the dip stick. Engine started well but the oil warning light on the dash stays on (it is in a TR7 body) and I am not sure on where to look to try and work out the problem. The engine has three sensors on the front of the block near the oil pump and the car has only had one attached to a cable since I have owned it. I did remove the cable from the sensor during the rebuild but failed to take a pic (I am now kicking myself) so am not sure it is on the right one. See attached pic - currently on the middle one as this is where the cable seems to bend towards.

Any advice on the sensors or trouble shooting this problem would be much appreciated, and do not worry about stating the obvious as it is mostly new to me.

thanks

[ChrisJC]

I would remove the distributor and a rocker cover. I would then spin the oil pump with an electric drill. If the drill seems to be 'working', i.e. not just spinning freely, and oil dribbles out of the rockers, then you just have a problem with the oil sensor (so probably the pressure switch). If it spins freely and no oil comes out, then don't run the engine, as the pump may need priming.

Chris.

[scudderfish]

If you're near Harpenden (J9 M1) I can lend you the tool to do this easily

[stevieturbo]

Well you've already tried 1 out of 3 spade terminals down there.

I'd try the farthest one first. The closest one looks like a primitive pressure sender, not a switch.

[Biffdiff42]

Thanks, I will try spinning the oil pump via the distributor drive and have a go at making my own tool for this as I live in Shropshire, but a kind offer to borrow yours.

[GDCobra]

How long did you have the oil pickup uncovered?
I dropped oil from my engine a while back and didn't re-fill for a few days (during winter, had other jobs on) and when I filled up and started again no pressure, seems the oil had all dribbled back from the pump so no longer primed.

I have a priming tool as mentioned above but never found it to work for me, possibly due to my system employing an external filter) so I had to pop the cover off the oil pump and fill with Vaseline (luckily I had some handy!) and this pulls the oil through no problem.

[Ian Anderson]

Hi

Another method is to overfill the sump with a couple of litres so the oil level is above the oil pump so the pump will be full. Then crank it over..

After pressure comes up drain of the excess to leave the oil at the correct level.

Presumably it is good old dinosaur juice…20w50

Ian

[Biffdiff42]

Hi

I had the sump off and oil pick up removed for about 4 months so plenty of time for the oil to run out, sadly

My oil pump and filter are the standard format and location.

I am using the 20/50 oil which seems to be the most popular option.

Is there ay chance that the oil pressure light will go out when using the electric drill option, if it does pick up the oil?

[Ian Anderson]

Normal oil ligh goes off between 5 and 10 psi

So yes I would expect spinning through the dizzy would generate that pressure

Ian

[stevieturbo]

Is there ay chance that the oil pressure light will go out when using the electric drill option, if it does pick up the oil?

This is the entire reason you would prime with the drill.

[Biffdiff42]

I made a drive shaft for the oil pump from a large screw driver and used an electric drill to turn it, initially at low speed and then slowly increasing the speed until reaching a medium drill speed but no joy with making the oil light go out. I could try taking off the oil pump and packing with vasoline as next step to help prime the pump but I am suspicious of the oil pressure sender unit and will remove this to check. Are there any simple ways of apply pressure to the sender which I can use on the bench to try and test it??? I presume on the electrical side the circuit simply opens and cuts the power to the warning light when the correct pressure is reached . If that is ok I will then try the vasoline in the pump option.

[stevieturbo]

If you're priming with the drill, you would easily feel when it is lifting oil and making pressure. Obviously the drill will slow as it's working harder with more resistance against it

Options depend on what tools you have available.

I've used a vacuum pump before on an oil gallery to try and assist pullling oil into the system during priming.

You can try and backfill the system through an opening, by pumping oil into the galleries, which will then get back into the pump to assist with priming.

As someone else suggested, you could massively overfill so the oil level is above the pump gears, to try and prime that way

Or take it all apart and try vaseline.

All and I'm sure many more are options. How long did you try the drill for....and obviously are you turning the correct direction ?

But yes, just remove the pressure switch, apply pressure to it and see when it goes open circuit.

[Biffdiff42]

During the priming process the drill was turning in a clockwise direction and for roughly 3 minutes, but no joy.

I have removed the oil sensor from the oil pump and checked it using a multi meter and bike pump and the sensor works so this suggests a lack of priming in the pump.

So, I have also removed and cleaned the oil pump cover and plan to pack it pack it with Vaseline and understand the importance of getting it in to all the nooks and crannies. I have also removed the oil filter and will top this up with oil when I put it back on but should I also pack the slightly domed area above the filter - see pic - with Vaseline as well ??

[r2d2hp]

I use an old Eezibleed Kit which I adapted. Connect to where the oil sensor goes. Fill with 20/50 and pressurise and wait for it to empty. If you then use your priming tool you will feel when it has oil pressure.

[GDCobra]

During the priming process the drill was turning in a clockwise direction and for roughly 3 minutes, but no joy.

I have removed the oil sensor from the oil pump and checked it using a multi meter and bike pump and the sensor works so this suggests a lack of priming in the pump.

So, I have also removed and cleaned the oil pump cover and plan to pack it pack it with Vaseline and understand the importance of getting it in to all the nooks and crannies. I have also removed the oil filter and will top this up with oil when I put it back on but should I also pack the slightly domed area above the filter - see pic - with Vaseline as well ??

As you now have the pump cover off it looks like you're well on the way to a solution.
I've tried the electric drill method several times in the past, even buying the correct tool, but never had any joy, every time I use the Vaseline method it has worked straight away. You mention in a previous post that the oil was out for a matter of months, this is ripe for allowing the oil to drain from the pump, mine was only a matter of days last time. Once you start spinning the pump (either using the starter motor or the drill tool) don't stop until pressure comes up.

You only need to pack the inards of the pump, from where you've taken the cover off, anything downstream including the domed area you mention is not necessary (shouldn't do any harm though).

Another thing is, although popular, it is not a good practice to pre-fill the oil filter. In doing so you are putting unfiltered oil into the post-filter location.
Admittedly this is very low risk but that is why it is advised against. In any case it will only take a couple of revolutions of the engine to fill up the filter usually before the engine fires.