Low Oil Pressure, Ish.

[hexhamstu 9]

Oil pressure seems low and doesn't seem to climb with the revs as I would expect.

 

Fairly sure it's not the sender as the stop light flickered when engined dropped to 800rpm is this normal?

 

Bottom end was rebuilt 4 or 5 years ago. Not sure on mileage since then. Top end recently rebuilt by miles. I've just been out to try and tighten the bottom pulley I only had a normal socket set no torque wrench. Didn't want to budge though so it definitely isn't loose but possible isn't correct torque setting.

 

https://www.dropbox.com/s/cc9byla8sf4rm4q/2014-04-01%2010.01.08.mov

 

https://www.dropbox.com/s/tnjtbvlacb9tcmk/2014-04-01%2009.57.21.mov

[welshpug 1,661]

when was the oil changed last? not running rich is it?

[hexhamstu 9]

Warm idle seems to sit on the bottom white line.

Oil and filter only few hundred miles old.

 

Don't think it's running rich, the idle is high because me and dan turn it up to avoid stop light

Edited April 1, 2014 by hexhamstu

[aldworth33 45 1 Cars]

There any oil leaks? Mines the same when it gets hot but mines got an oil leak so I know where the pressure is going. It's only at idle it drops below quarter on the gauge

[hexhamstu 9]

Sump is clean so nothing major. There was oil all over the gearbox but thats just because theres no catch tank and the hoses were left pointing that way. How much oil should end up in the catch tank?

(Its on throttle bodies so oil breather hoses off filler cap dont go anywhere)

[aldworth33 45 1 Cars]

The oil on mine is on the back of the engine and allover the gearbox so maybe worth checking it's 100% coming out the breathers on yours to rule out simple things 1st

[Tom Fenton 1,542]

Two things.

 

1- If you are using the standard gauge and sender to judge this you are wasting your time. it is at best a guess-o-meter. Get a mechanical test gauge fitted to see what you actually have.

 

2- External oil leaks have absolutely no effect on oil pressure, until they have leaked out enough oil so the oil pump is sucking air from the sump

[Anthony 1,003]

As Tom says, the standard guage is a bit of a guessometer and not exactly renowned for accuracy.

 

That said, if the low pressure light flicks on as well then something doesn't sound right as the gauge and light are independant.

 

It might well be the gauge/sender, but the first thing that struck me on that video was how slow the oil pressure was to pick up with the revs - it should be pretty much instantaneous yet yours is lagging badly behind. The reading at idle is low given that the oil is cold (assuming the gauge works) and it's idling high, but again, you can't read too much into the gauge readings as they will vary quite alot between cars.

 

Given that you've checked the basics - fresh oil and that the pulley bolt is tight - next I'd get a half-decent mechanical sender on it and see just how bad the oil pressure is, and if that confirms it, it's sump off time and start with inspecting the oil pump I'd say.

[hexhamstu 9]

Best place to purchase one?

[hexhamstu 9]

Right got a test gauge on it, rises much faster on the test gauge. Started at 3 bar when cold dropped to 2 bar when warm. Didn't get to running temp as not to keen on abusing the neighbours ears. Rose to 5-6 bar when revved.

 

Another question while we're at it, do I need that vac coming off the fuel regulator? Dan doesn't have one and his is fine. Would like to get rid of all the extra hoses and just run one to the brakes and sunroof if possible.

Cold:

https://www.dropbox.com/s/p5krv3zvrgrt095/2014-04-01%2017.34.40.mov

Warm:

https://www.dropbox.com/s/9jez3mzmeounytq/2014-04-01%2017.38.56.mov

 

https://www.dropbox.com/s/sy99sh8k8ngllkp/2014-04-01%2011.57.00.jpg

[Anthony 1,003]

Another question while we're at it, do I need that vac coming off the fuel regulator? Dan doesn't have one and his is fine.

Assuming that you're running standard management, yes you do need to keep it.

 

If running aftermarket (like Dan) then you don't need it providing that it was mapped with it disconnected.

[hexhamstu 9]

Was mapped with it connected

What should the oil pressures be? I read it on a thread but I can't find it now.

[hexhamstu 9]

 

(info for mi16) I got 5.5 bar at 4000rpm at a not cold not warm engine temp. So can only assume its fine?

Edited April 1, 2014 by hexhamstu

[hexhamstu 9]

Messed the videos up before, they are both warm. This one is from cold:

 

https://www.dropbox.com/s/8a9hpu7c7j5sk8c/2014-04-01%2017.32.00.mov

[welshpug 1,661]

sounds good yes, I was wondering, Alternator voltage output might affect the gauge reading, though wouldn't affect the pressure switch.

[hexhamstu 9]

The stop light flickered the once when me and dan had been checking if his car was much quicker than mine.... When the revs dropped a bit at the lights.

[hexhamstu 9]

You think fitting one of the wizardy/magic not much different from standard springs will be of any benefit?

[hexhamstu 9]

Replaced sensor, still the same. Guess it's time to trace the wire and replace it?

[welshpug 1,661]

you mean the switch? time for a pressure test with a gauge.

[hexhamstu 9]

I've already used a gauge, it said it was fine.

 

Right got a test gauge on it, rises much faster on the test gauge. Started at 3 bar when cold dropped to 2 bar when warm. Didn't get to running temp as not to keen on abusing the neighbours ears. Rose to 5-6 bar when revved.

 

Another question while we're at it, do I need that vac coming off the fuel regulator? Dan doesn't have one and his is fine. Would like to get rid of all the extra hoses and just run one to the brakes and sunroof if possible.

Cold:

https://www.dropbox.com/s/p5krv3zvrgrt095/2014-04-01%2017.34.40.mov

Warm:

https://www.dropbox.com/s/9jez3mzmeounytq/2014-04-01%2017.38.56.mov

 

https://www.dropbox.com/s/sy99sh8k8ngllkp/2014-04-01%2011.57.00.jpg

[hexhamstu 9]

When the stop light came on that one time, I think the little red light at the end of the coolant temp lit up as well. Does that mean it was just the alternator?

[welshpug 1,661]

DERP, that was aaages ago.

 

 

might be the alternator dropping volts a bit, I think that little red light does come on with ignition on engine off doesn't it?

[hexhamstu 9]

DERP, that was aaages ago.

 

 

might be the alternator dropping volts a bit, I think that little red light does come on with ignition on engine off doesn't it?

 

Yeah I think so, so I think that STOP light incident was a false alarm. On a side issue, I had the inlet off and just reused the gasket when I re-assembled. Now the car bogs down for a second when you go from cruising to WOT quickly. Could this be an air leak? I've ordered a new gasket, hopefully this solves it.

Edited April 23, 2014 by hexhamstu

[RossD 44]

Surely the battery light would come on if the alternator output was dropping? The low oil pressure light, STOP light and coolant light are all linked in the dash, so they will come on together if there is an oil pressure or coolant temp issue.

 

One way to test this would be to remove the aux belt and start the engine, (so the alternator isn't turning) and see if the lights on the dash stay on.

[Anthony 1,003]

Ross is right - STOP, oil pressure and coolant temp lights are all triggered by the low oil pressure switch.

 

Alternator only does the battery/charge warning light.

 

Obviously the lower the idle speed, the slower the oil pump is turning and the lower the oil pressure - so if the idle speed drops noticeably then so will the oil pressure (and when the idle is low enough, the alternator will be turning too slowly to charge and the battery light will come on)

 

This thread is starting to get a bit confusing, but have you tested the oil pressure with a mechanical gauge with hot oil? Doing it when the coolant has only just come up to temperature as I think you were implying is no good really as the oil will still be comparitively cold and hence giving higher pressure.