No oil pressure

[Gray]

As the title says, my freshly built 970 has up until this morning been ticking over nicely with tons of pressure, but whilst still faffing about getting my smiths tacho to work this morning I flicked the engine on to notice no oil pressure, no pipes blown off, do gauges just pack up? not heard of that before. Any ideas appreciated. Cheers Graeme

[atlanticdave]

Is there any rattles coming from the engine when this happened?

I would whip the plugs out so it cant start, and try conecting another guage, turn the engine over until you see oil press, r if you dont have another guage to try then just vent the conection into a tub an see if oil comes out the press pipe when turning the car over, it can take a bit of time but it will iron out if its a faulty gauge.

Start with the simple stuff first, fingers crossed its not a mechanical failure, if the engine was still quite on start up it might be ok. Also, is there no oil press warning light? or do you not have a t-piece inline to have both guage and light? Also check the relief valve in the block. I had this many years ago but unfortuantley there was a spun shell on a fresh built engine, I have also had the guage just die and give us a real fright.

[Gray]

Thanks for the input Dave, I pulled the coil wire straight off and pulled the plugs to spin it over quicker, normally was getting 100psi on the starter, I will dig another gauge out and try that, Bryan Slark built the engine up so I would of thought that it should be well built. No noises either however it barley had fired when I saw the lack of movement in the gauge.

[JC T ONE]

Check the pressure valve piston ? they sometime stick.
picture here
http://www.mra-minis.co.uk/classic-mini ... ng-kit.htm

[ricardo]

Gray,

did you (Slark) fit a modern oil pump? Ie, was a new hole drilled and tapped? If so, was it done properly - deepness and correct thread? Are the bolts used on the oil pump the correct ones?

I know someone who drilled the block with a tapper in mm and used a short bolt instead of the normal length. The result was a relief of the oil pump resulting in oil pressure loss right after starting the engine.

Another friend who rebuilds engines had one time a customer with a problem no one (until then) could resolve. The problem turned out to be a broken bolt (just the tip) at the end of one of the oil pump bolt holes. You could torque the oil pump to the specified torque and 'feel' it to be ok, but it wasn't...

[Gray]

nos s pump fitted to the block so no need for any drilling. The engine has been running fine since I with outstanding op so for it to stop overnight seems a bit strange. I put an airline on the gauge which registers a pressure OK, turned the engine over with the gauge rubber pipe disconnected and nothing came out but when I tried the same again with the feed pipe out of the block I got a hell of a load of oil surge out on first slightest turn over. I need to try a new feed pipe as the one fitted broke as I took it out the block. No oil light showing.

[carbon]

If you're getting oil from the pump OK then sounds like this part is OK.

Did you take the oil gallery plugs out, and if so what type did you fit? I have had one pop out on a very cold morning when starting from cold. It was the one which is at flywheel end, as the other one is partly covered by the timing cover plate. This gives zero oil pressure...

[atlanticdave]

So whats the latest news?

D.

[Gray]

New pipe to the gauge and still no op!! although when the pipe is out the block and I turn the lump over oil comes out the block when the pipe adapter is put back in the block hardly any oil emerges through it so no real pressure, even when cranked for a while I would expect it to spray with a force out the hole, so no real progress at the moment, to get so far and to get this c*ck up has got me a bit vexed!!

[atlanticdave]

mmm not good, and yeah a hassle you could do without. Have you contacted Slark about it to see if he has any views on the matter?

[scooperman]

Stuck relief valve or popped galley plug. Stop spinning the crank with the starter until you pressurize the galleys with oil. On new motors I use a boat winterizing sump pump like this one... http://www.shurflo.com/files/Education- ... 05-426.pdf (PDF warning).

[guru_1071]

you dont think that its the shaft of the pump turning on the annulus do you?

as s pumps have been nla for years ive seen people mod slot drive pumps by swopping the centre shaft

[Gray]

A total bu**er to get to this stage and have the OP go AWOL!!



The oil pump was a new pump I bought off Tim at Minimail about 15 yrs ago so should be no worries there, I stilll have one in stock though, Looks like it will all have to be pulled out again now
I installed the engine in about October and have run it for only minute at a time ever since it has always been 100psi on the starter which I thought was good. I cannot remember what happened with the gallery plugs on the build.

[66S]

Just thinking aloud here. 100 psi is high and I wonder whether that initially encouraged the oil pump shaft to slip in the rotor ?? Sorry to hear of your problems Gray, I share your disappointment and frustration.

Al

[JC T ONE]

A total bu**er to get to this stage and have the OP go AWOL!!
The oil pump was a new pump I bought off Tim at Minimail about 15 yrs ago so should be no worries there, I stilll have one in stock though, Looks like it will all have to be pulled out again now

I feel for you thats one nice looking motor / engine bay.

But remember to check the pressure valve, before you pull the engine.

[guru_1071]

100 psi is far to high, i always think that you should aim for 75 psi cold running, less when hot.


just think, that poor little pump has to push that extra pressure round, and most of it is dumped by the pressure release valve.


its this high pressure that breaks the pumps, and can cause the coolers to burst.


i recently saw a 1071 that had pressure so high that the pin in the cam broke as it was the weakest part.

[Vegard]

I had this happen on a race engine last year. All of the sudden, all oil pressure was gone. When Iremoved the block to filter pipe, oil poured out, I just couldn't get it. The cause was that the bung in the block oil gallery (998) behind the flywheel had come loose. When the pipe was removed, all oil flowed out from there as there was no "back pressure". When the pipe was fitted again, all oil went out of the gallery and straight into the sump.

Engine out job to check unfortunately.

[Andrew1967]

Just thinking aloud here. 100 psi is high and I wonder whether that initially encouraged the oil pump shaft to slip in the rotor ?? Sorry to hear of your problems Gray, I share your disappointment and frustration.

Al

Gray, that's real bad news.

I'd agree with Al, 100 psi is high, especially when just cranking over. My S engine runs at about 85 when cold and revving and 75 ticking over.

Looks a great engine bay though, what a bloody shame it's looking like it will have to be stripped.

[Gray]

Well carbon was the winning guess! flywheel end gallery plug was blown out. When I had found it in the gearbox there was loctite on it so had not just been punched in. Now on my 1275 these have been tapped and a grub screw plug put in, can this be done without the whole bottom end having to stripped out to ensure no debris is in the system?



Offending item.

[scooperman]

Is it the gallery that feeds the main bearings? My recollection is that the passage going to the 3rd main is close to that plug. If so, it would be difficult to tap the gallery for a threaded plug without getting swarf in there. I will look at a tapped-gallery block next time I am at the shop, but I think if you want to plug it without a teardown, then you are back to using a pressed-in plug.