Running in - Oil Pressures

[gjz30075]

Time to drop the pan and look at the bearings. Now's the time to make the crossmember removable, if it's
not already.

[l10tus]

Already done the conversion and dropped the pan - no issues with any of the bearings - engine runs like a sewing machine - not nasty noises, etc. - completely stumped!!!!

[elj221c]

Try bleeding the pipe at the gauge end.

A bit tricky to do without getting covered in oil but it worked for me once a long time ago.....

[pharriso]

Try bleeding the pipe at the gauge end.

A bit tricky to do without getting covered in oil but it worked for me once a long time ago.....

Roy On Monday he posted "Undid the Oil Gauge connection at the block - started the car briefly - no oil coming out of the block !" ; how's he going to bleed it?

As to "Re-torque the head bolts"... sure that will need doing at some point, but that's like polishing the brass on the titanic at the moment...

Did you try the vaseline in the oil pump trick?

[rgh0]

The pressure relief valve in the pump jammed open as suggested before sounds the best bet

cheers
Rohan

[billwill]

Just possibly something is blocking one of the oil galleries.

Do you have a compressed air gun or can you buy a can of air-blower.

Then try blowing in reverse through the oil presssure gauge outlet.

Beware might be very messy.

[elj221c]

Try bleeding the pipe at the gauge end.

A bit tricky to do without getting covered in oil but it worked for me once a long time ago.....

Roy On Monday he posted "Undid the Oil Gauge connection at the block - started the car briefly - no oil coming out of the block !" ; how's he going to bleed it?

With great difficulty!

[Craven]

Just looking for clues, is there plenty of oil seen under the cam cover, ie feed to top of the engine.

[mbell]

The lack of oil at the gauge take off confirms the problem is between the oil pick and and the gauge take of. So it unlikely to be an oil leak some where else in the engine.

So possible causes I'd think are:
1) Pick-up blocked/not connected
2) Blockage between pick up and pump
3) Pump not primed
4) Pump not functional
5) Pressure relief valve stuck open
6) block age in oil gallery after pump

I think 1 & 4 have been ruled out, unlikely to be 3 with a running engine. I think 5 is most likely and not too hard to check, remove the filter an operate the valve with a screw driver.

[l10tus]

Gents,

Thanks for sticking with me on this one - I'm a mechanical engineer but guess I'm really stumped this time!

By the way, great observations Phil. - thanks!

the list of possibilities that mbell, Rohan and billwill suggest, seem to me to be spot on, but the fact that the oil pressure didn't return the next day is worrying!

Having removed the pump it appears to be as wet and well primed as I could make it, (if I were to prime it by adding oil thru' the open gearbox to the gears inside), so think the possibility of the oil running back and leaving the pump dry dosn't stack up.? (Although I also thought this a distinct possibility at first!) - it's really wet with oil.

The pump appears to be ok?

The gauze filter being still correctly in place and attached to the pickup pipe, wouldn't allow any foreign matter to enter the oil galleries, blocking them would it? (Gauze filter is made of steel mesh with approx 3mm squares)- so the pump and galleries should be able to handle anything that passes thru' here ???

When the engine was rebuilt it was hot dipped to remove the sludge - but I can't honestly remember clearing all the oil ways by removing the blanking plugs ( are there 2 no. .?)

So there is a possibility that something has been dislodged when I gave the engine more revs, for a very short period? - and this in turn has blocked an oil Way?

Q: what size are the oil ways ? Could they become blocked - with say a bead of loose RTV ??

I'm going to fit a new standard pump, Silcolene Classic 20/50 oil and new filter tomorrow and try again - using the starter motor with spark plugs removed.

I'll let you know how I get on!

Thanks for all the suggestions, really appreciated!

Regards,

Phil.

[TroonSprint]

I don't want to jinx your efforts, but when I was preparing my TC engine just a few weeks ago, I found it impossible to generate oil pressure just using the starter with the spark plugs out. But as soon the engine fired up, the pressure was there. I packed the pump with grease to get it started.

By the way, I have never, in over 40 years of messing about with British car engines, bled an oil pressure gauge. It has never been necessary.
Mike

[rcraven]

Unless you're afraid too much more testing might damage the engine, would it not be wise to change one thing at a time, otherwise you might cure it without discovering exactly what the cure was?

PS I did once bleed an oil pressure gauge pipe, and a bit of of muck came out and produced a temporary improvement in the reading.

[Panda]

I have come across a case of a newly rebuilt engine with very low oil pressure and it turned out to have had the main bearing tunnels line bored to accept .015" outside diameter bigger main bearings. Unfortunately the engine builder fitted std. od. bearings with consequently much too much clearance and loss of oil pressure. Strangely, there was no obvious knocking, although the crank could be rocked up and down with a lot of play evident!!
Alan P.

[Chancer]

Your description of checking the pump did not mention the pressure relief valve, this is the most likely suspect given that the pump is primed.

[l10tus]

Well, I thought I'd give the pump another once over----

I compared the existing old pump with a new one - see if you can spot the difference??

Yes, the oil pressure relief valve is stuck open.

This I didn't realise when just inspecting the first pump on its own.

But when compared with the new replacement is obviously stuck open.

In my ignorance I thought the little spring loaded valve in the pump top was the relief valve, which was ok, and moved freely.

I then looked back at the previous posts on the forum that mentioned an engine builder always striping the valve and polishing it before use.
So I fiddled with a screwdriver and managed to release the valve, with a 'clock' it jumped forwards to its normal closed position.

I will obviously use the new pump, but any thoughts on why it jammed?

I was thinking maybe it was because it had been fitted to the engine, unused for several years and may have dried out or become contaminated with a small amount of corrosion?

Funny it worked for 250 miles though???

Anyway I'm hoping to reinstall the new pump, carbs and ancillaries over the next few nights, and I'll report back to close this one out (hopefully!)

For all those who suggested the pressure relief valve as the culprit - well done.!

Regards,

Phil.