The V8 Owners Forum -

Hi All,

Just completed my first v8 new build and running into a few oil problems at start-up.

Firstly, no oil pressure.
Span the pump via the dizzy. It eventually primed and I got a good stream of oil coming out of the hose that feeds the gauge.

Started up the engine.
Can't get more than 10 psi at the gauge.
My oil sender is plumbed into the outlet of the my remote oil filter - I thought that could be the cause of a low reading.
The engine was a little noisy and didn’t quite down after 4-5 minutes running, so I thought I should investigate further, especially with the low oil pressure reading.

Pulled a rocker cover off and span the pump via the dizzy - there was a little bit of oil from when it was running, but no sign of any oil when spinning the pump via the dizzy.
Pulled off the outlet hose from the oil filter and span the pump via the dizzy - got a good gush of oil.
Obviously the oil pump is working or I won’t have oil going through the filter and into the outlet hose but with the low pressure reading I suspect a problem elsewhere.

Not really sure where I should start looking or what other tests I can do to isolate the problem.

Does anyone have any ideas please?

Thx - Stephen

The only easy thing I can think of is the oil pressure relief valve stuck open. You may get a good gush of oil from the filter outlet but there may not be much pressure , try putting your finger over the end of the hose to see if there is pressure ,like spraying with the garden hose .

Thank you, good idea - I'm going to look at prv this morning and make sure it's assembled properly.
- Stephen

From above do you have remote oil filter?
Are the pipes connected for flow and connected correctly?
Some filters also have non return valves fitted and if flow and return are wrong way round you are pushing against said valve.

Just more to check!

Ian

Hi Ian,

Yes I'm running a remote filter. I've got oil flow from the pump, through the filter and into the output hose so I think the flow is correct.
The remote header has an arrow showing input.
So Output from pump to input of filter.
Output of filter, back into the pump.
- Stephen

You could try removing the filter assembly from the system and using drill again to see if you get oil at rockers. Removing one more possible cause from your fault finding.

Or try a different oil pressure gauge, they do go faulty,
Did your idiot oil light go out when it was running?

Ian

Using the drill I'm getting oil at the rockers on both sides. On the left side (2,4,6,8) it seems to be what I would expect. On the right side (where I originally checked) not very much, but I am getting a little.

I checked the iD markings on the rocker shaft to ensure it's the right way around. The left hand side has the groove at 1:00 o'clock as per the manual. The right side at 11:00 o'clock. Assuming I'm look at the correct mark I guess this could be causing a problem. The mark I'm looking at is a groove on the rocker arm not on the shaft. After removing the pin and washers at the end of the rocker shaft I couldn't see any other iD marks.

Re the gauge.
I haven't got the right fittings to try my alternative gauge at the moment and my idiot light isn't working. I haven't worked out why yet. Might not be earthing properly.

- Stephen

The rocker shaft has oil holes in it that need to be correctly positioned. I'd orientate it by that rather than looking for a mark. Make sure it's assembled correctly.

Cliff4WD wrote: ↑Tue Sep 08, 2020 12:16 pm The rocker shaft has oil holes in it that need to be correctly positioned. I'd orientate it by that rather than looking for a mark. Make sure it's assembled correctly.

Ah, no , there are notches on the ends of the rocker shafts that indicate correct alignment ,both heads are assembled the same as they are interchangable . The notch should be at the top of each shaft assy ,at the front on the right hand bank and at the rear on the left bank. The pedestals are all machined on the bottom so that any one of them will fit any way round and the two front ones will then cover the oil supply holes in the heads and feed oil up around the mounting bolt and into the shafts .
Oh ,and cliff4wd, you forgot to tell us how to correctly orientate the shafts by looking at the oil holes

Oil holes face towards the valley/camshaft area on both banks IIRC

Mc Tool wrote: ↑Thu Sep 10, 2020 5:45 am

Cliff4WD wrote: ↑Tue Sep 08, 2020 12:16 pm The rocker shaft has oil holes in it that need to be correctly positioned. I'd orientate it by that rather than looking for a mark. Make sure it's assembled correctly.

Ah, no , there are notches on the ends of the rocker shafts that indicate correct alignment ,both heads are assembled the same as they are interchangable . The notch should be at the top of each shaft assy ,at the front on the right hand bank and at the rear on the left bank. The pedestals are all machined on the bottom so that any one of them will fit any way round and the two front ones will then cover the oil supply holes in the heads and feed oil up around the mounting bolt and into the shafts .
Oh ,and cliff4wd, you forgot to tell us how to correctly orientate the shafts by looking at the oil holes

Well excuse me for trying to be helpful. He did say he couldn't see any marks (the notches) and oil wasn't flowing through one shaft, hence why I pointed out the oil holes in shaft, i.e., work out the correct orientation in absence of the notches.

So is this resolved? What was the cause?

Sorry for the late response, been on a journey with this one. I did check the rockers and all the holes were pointing in the right direction. Cliff was exactly right the notches appear at the front and back and are therefore in the correct places. The problem turned out to be a sticking relief valve that someone did mention - thank you!
I ordered a new one from Rimmers, fitted that and now have oil pressure.

Unfortunately still not quite there yet. Now it's running the lifters didn't really quiten down very much on one side (1,3,5,7) and tapping away quite loudly. I thought I'd re-check the assembly in case I did something wrong in haste. All seemed okay but I did spot this hole in one of the rocker arms. (See attached pic in link below).

https://www.dropbox.com/s/zg62q23y3ogqk ... m.jpg?dl=0

I'm not sure that is the cause of the problem but what do you think I should do about this? I didn't replace the rocker assembly's during the build.

1. Just ignore it - do nothing
2. Replace a single rocker arm
3. Replace the entire side rocker arms and shaft
4. Replace both sides

As regards the noisy tappet, I don't think this hole is likely to be the cause. I was thinking of re-checking the pre load.

Any thoughts much appreciated - Stephen

aspira wrote: ↑Fri Sep 18, 2020 7:46 pm Cliff was exactly right the notches appear at the front and back and are therefore in the correct places. The problem turned out to be a sticking relief valve that someone did mention - thank you!

Actually , that was me ....both times Im pleased you got that part sorted

aspira wrote: ↑Fri Sep 18, 2020 7:46 pm

https://www.dropbox.com/s/zg62q23y3ogqk ... m.jpg?dl=0

I'm not sure that is the cause of the problem but what do you think I should do about this? I didn't replace the rocker assembly's during the build.

1. Just ignore it - do nothing
2. Replace a single rocker arm
3. Replace the entire side rocker arms and shaft
4. Replace both sides

As regards the noisy tappet, I don't think this hole is likely to be the cause. I was thinking of re-checking the pre load.

Any thoughts much appreciated - Stephen

That hole looks like a casting anomaly and as long as the hole doesn't go right thru Id be inclined to leave it . As for the noisey lifters ,Id wait till you have the new relief valve fitted and have verified good oil pressure .....at least 40 psi @3000rpm and at least 15-20psi at a hot idle. There is a higher pressure relief spring available (spec'ed for the MG with the rover v8 ) but the higher the oil pressure the harder it is on the oil pump drive and school of thought is 40psi is enough for a stock engine .