V6 oil pressure.. ?

[savage1987]

Just gave the VN its 5000km oil change, as usual I let it idle for about 5min whilst jacking it up and getting the stands under there so the oil flows a bit better. Just out of curiosity (motor is quite noisy, I'm always curious) I pulled off the oil cap and stuck my finger in there to see if everything was coated in oil.. it wasn't. It was nearly bone dry. Is that normal after idling for so long?

I thought it might just be because the oil was a bit low (around the 'add' mark on the dipstick) so I decided to try it again after the oil change. I changed the oil and filter as normal and filled it to the appropriate level.. unfortunately draining the old oil into a container revealed there was only about 2.5L of it!!! What's the capacity of the V6 sump? I'm a little concerned.. mine has a bit of a dent on the bottom, but not that much of a dent!

After the oil change I started it up again and pulled the oil cap off.. nothing. I gave it a few revs (probably around 1500-1800rpm) and still no oil flow.

Is this normal? I'm not sure at all but I thought you were meant to have a little bit of oil through there.

If anyone has anything to offer I'm all ears.. I don't know enough about oil feeds to know whether to be concerned or not.
Sam

[Bz Kn33z]

It should have oil in there mine does, i think oil also goes up the push rods cause there is a hole but i could be wrong, mine where blocked so i cleaned them out,
The oil pick up could be clogged with crap after the amount of Klm your car has done i think it would be or the oil pump sh1t its self but if there isnt much oil up there it would be abit noisey.

[vnv8driver]

not much oil reaches the heads on a motor that doesnt have over head cams, but it shouldnt be bone dry...

[Pub247]

Be kneez is right the oil comes up through the push rods and pools in the rockers there should be oil on the rockers if not theres something wrong. testing oil pressure is a good place to start. I doubt its a blocked pick up as you wouldn't be getting oil anywhere. And that would make a fair amount of noise

[vnv8driver]

im 99% sure the oil in your motor is capable of reaching the rocker gear from the crankcase, if it didnt when you fill the oil up it would just sit in the rocker cover....

Like i said its not meant to have much oil (hardly any at all), not like it supposed to be pooled up.


Do you do engine oil flush's at oil changes?

[vnv8driver]

Be kneez is right the oil comes up through the push rods and pools in the rockers there should be oil on the rockers if not theres something wrong. testing oil pressure is a good place to start. I doubt its a blocked pick up as you wouldn't be getting oil anywhere. And that would make a fair amount of noise

If the oil pressure sensors working correctly, the buick v6 has a safety feature which cuts out the fuel pump when oil pressure has been lost, obviously to save the motor so possibly theres nothing out of the ordinary

[savage1987]

The oil pressure switch is brand new, I replaced it a couple of months ago. The top end is quite noisy but I just put it down to being old

No I don't do engine flushes at oil change time; I change the oil every 5000 on the dot and that seems to flush it out enough. Doesn't seem to need it anyway, the rocker gear is so clean you could eat off it.. my VR isn't, that's full of ****. Even that seems to be clearing up a bit with my 5000km changes though, but I digress

What's the charge for an oil pressure test? What about a compression test, just for interest's sake? I've never had either done.

[Pub247]

If the oil pressure sensors working correctly, the buick v6 has a safety feature which cuts out the fuel pump when oil pressure has been lost, obviously to save the motor so possibly theres nothing out of the ordinary

Oh really and how come i can a run motor with no sender unit installed and a pressure gauge instead? Thats a load of crap

[commsirac]

If the oil pressure sensors working correctly, the buick v6 has a safety feature which cuts out the fuel pump when oil pressure has been lost, obviously to save the motor so possibly theres nothing out of the ordinary

Are you sure about this? Sounds like lunacy to me.....Im unaware that any manufacturer includes a feature which disables the engine and leaves the driver in an unsafe or precarious position on the road.

[Pub247]

im 99% sure the oil in your motor is capable of reaching the rocker gear from the crankcase, if it didnt when you fill the oil up it would just sit in the rocker cover....

Like i said its not meant to have much oil (hardly any at all), not like it supposed to be pooled up.


Do you do engine oil flush's at oil changes?

WTF? If you read my post the oil should pool in the rockers. There's no way it will pool in the heads as they have drainage holes in them to feed the oil back to the sump. That has nothing to do with feeding oil from the sump to the top end.

The oil pressure switch is brand new, I replaced it a couple of months ago. The top end is quite noisy but I just put it down to being old

No I don't do engine flushes at oil change time; I change the oil every 5000 on the dot and that seems to flush it out enough. Doesn't seem to need it anyway, the rocker gear is so clean you could eat off it.. my VR isn't, that's full of ****. Even that seems to be clearing up a bit with my 5000km changes though, but I digress

What's the charge for an oil pressure test? What about a compression test, just for interest's sake? I've never had either done.

I'm not sure what a mechanic would charge for a compression test but theres not much to it $80 at the most i'd say there's a couple different ways of doing some are electronic some might just get out the old fanished gauge which is the best way imo.
Checking oil pressure is easy takes 5 mins to put the bung in and hook up a gauge shouldnt cost all that much. Anyways getting a mechanic to check should be cheaper than buying the gauges.

[savage1987]

Might get an oil pressure test, although I refuse to spend any more cash on this car... maybe I should just leave it alone, it's not making any more noises than usual after all

[vnv8driver]

If you guys know more than a holden technition then go ahead and argue it, cause i was told by 2 of them years ago when i first became interested in vn's.

Couldnt care less anyway got better things to do than argue, cya

[jas98]

the rockers do get oil in them.....but not allot just enough to help them move without seizing.

as for the oil pressure switch this is true..as i have also been told this by the local holden and other mechanics...also states it in some of the repair manuals as well. Like if you were involved in a crash and the car is upside down you are unconscious and the engine is still running , this will cause no oil pressure and cut the fuel....its a safety feature that most cars are required to have. (all new ones should have this feature)

[immortality]

next oil change put a oil flush through the engine first. if there is a lot of gunk buildup in the lifters and pushrods then there won't be enough oil getting to the rockers, these will eventually fail.

yes, the fuel pump is wired through the oil pressure switch. you'll note that when you shut the engine down you can still hear the fuel pump run for a few seconds after the engine stops. the pump also has a power feed controlled from the ECU which is the reason it will work without the factory oil pressure sender fitted.

[savage1987]

you'll note that when you shut the engine down you can still hear the fuel pump run for a few seconds after the engine stops. the pump also has a power feed controlled from the ECU which is the reason it will work without the factory oil pressure sender fitted.

Thank you!! I have always wondered why the f pump keeps going when the motor's off.. seems so pointless haha

I don't really feel too good about engine flushing a 500,000km motor.. it's been serviced every 5000 since almost new so surely that would have kept it flushed enough...? I'm just worried it could do more harm than good.. but I don't know enough about it to make a decision either way at the moment so I'll take advice on this

[immortality]

I don't really feel too good about engine flushing a 500,000km motor.. it's been serviced every 5000 since almost new so surely that would have kept it flushed enough...? I'm just worried it could do more harm than good.. but I don't know enough about it to make a decision either way at the moment so I'll take advice on this

unfortunatly just doing oil changes doesn't quiet flush everything out. but as you say. in a old engine you risk cleaning out stuff you'd rather want to stay in there.

i once had a old VK with a very tired 3.3 i'd dropped in it cause the original one got fried and didn't run. though i'd be nice and give it an oil change. all was good for the first 20 mins untill she got up to temp. pulled off the motorway and stopped at the lights and watched the oil pressure drop to almost zero and the warning light come on. drove it like that for another 2 years. just didn't like idling

if it concerns you, pull of the rockers and pull the pushrods out and give em a good clean. it may be enough to restore full oil flow to the rockers

[Matt_vp]

there is a safty feature built in that cuts the fuel when there is no oil pressure, if u look at a wiring diagram then u will see that the oil pressure sensor and fuel pump are wired up together. maybe check u know what u are talking about before posting ****, its comments like this that make it hard for people to work out problems
Matt

[Cheap6]

there is a safty feature built in that cuts the fuel when there is no oil pressure, if u look at a wiring diagram then u will see that the oil pressure sensor and fuel pump are wired up together. maybe check u know what u are talking about before posting ****, its comments like this that make it hard for people to work out problems
Matt

Sort of. The oil pressure and the ECM switch the fuel pump, in parallel. If either one is operating (switching) the fuel pump will have power i.e. both have to be missing for the fuel pump not to have power. I am not sure why this has been done but it may simply be redundancy to add reliability.

One consequence of this set up is that an inoperative fuel pump relay will only be manifested in extended cranking time, until oil pressure is generated and the oil pressure switch operates the fuel pump.

If anyone wants to check whether an absent oil pressure switch will stop the fuel pump, simply bridge the switched side of the fuel pump wiring at the relay socket with the engine off (i.e. with no oil pressure present). The fuel pump will run.

[Pub247]

there is a safty feature built in that cuts the fuel when there is no oil pressure, if u look at a wiring diagram then u will see that the oil pressure sensor and fuel pump are wired up together. maybe check u know what u are talking about before posting ****, its comments like this that make it hard for people to work out problems
Matt

I'm not talking **** matt if you read my post i clearly state that the motor will run without an oil pressure sender unit or it not hooked up. As cheap 6 states it requires the ecu not to be working aswell for the fuel pump cut. And i do know what i'm talking about I never said there wasnt any safety circuit i merely stated what vnv8driver said is wrong. The motor WILL run without oil pressure sender unit hooked up. I know because i have done this many times while running motors that i rebuilt, in.
So how about everybody here get all the facts before the go and act like they know what they're talking about

[savage1987]

Back on topic, all I'd need to remove the pushrods is a torque wrench once the covers are off, right? Never pulled apart even that much of the internals before..

[centy]

If you guys know more than a holden technition then go ahead and argue it, cause i was told by 2 of them years ago when i first became interested in vn's.

Couldnt care less anyway got better things to do than argue, cya

silly, and just plain wrong.

mate just your socket set to loosen the rockers of enough to remove the rods.
i would suggest one at a time so as not to mix them up.
also look for flat spots bends and any other signs of abnormal wear.
if you find a rs one then ask at the local wreckers for a couple.
after cleaning reassemble and adjust.
sorry not sure of the adjustments atm. Someone else will be able to help there.
Kero or diesel is a good cleaning aject as it is compatable with most things that have oil in them, like auto clutch packs, so i would not expet it to do any damage.

[commsirac]

Sort of. The oil pressure and the ECM switch the fuel pump, in parallel. If either one is operating (switching) the fuel pump will have power i.e. both have to be missing for the fuel pump not to have power. I am not sure why this has been done but it may simply be redundancy to add reliability.

One consequence of this set up is that an inoperative fuel pump relay will only be manifested in extended cranking time, until oil pressure is generated and the oil pressure switch operates the fuel pump.

If anyone wants to check whether an absent oil pressure switch will stop the fuel pump, simply bridge the switched side of the fuel pump wiring at the relay socket with the engine off (i.e. with no oil pressure present). The fuel pump will run.

That makes sense cheap 6.

As I posted previously, any design that shuts the motor down for low oil pressure, high temperature etc could leave the driver in a very unsafe position on the road(use your imagination folks).......hence the reason the low oil pressure should not shut down the fuel pump. What would be the point of having an oil pressure warning light......the motor would stop.

I know many people who fit aftermarket electric fuel pumps on earlier model cars have them wired this way......but its not a good idea! Best to have a tachiometric or vac relay for that sort of thing.

[PaRaDoX]

do a burnout, should fix it..

you know its possible your oil pickup is blocked and that "noisy" sound is the sound of your bearings getting worn down to nothing!

[Pub247]

silly, and just plain wrong.

mate just your socket set to loosen the rockers of enough to remove the rods.
i would suggest one at a time so as not to mix them up.
also look for flat spots bends and any other signs of abnormal wear.
if you find a rs one then ask at the local wreckers for a couple.
after cleaning reassemble and adjust.
sorry not sure of the adjustments atm. Someone else will be able to help there.
Kero or diesel is a good cleaning aject as it is compatable with most things that have oil in them, like auto clutch packs, so i would not expet it to do any damage.

Centy got the right idea. You wil probably need to totally remove the rockers and pushrods give them a good clean blow some compressed air through the pushrods if you can otherwise just use your lungs.
There's no need to adjust them as they are hydraulic just make sure you torque them to spec. Not sure which model you have but Series 2 onwards are 32nm Series 1 are higher at about 45nm

Paradox makes a good point but v6 pick-ups aren't as prone as v8's to blocking

[savage1987]

It's a s1.

If I thought it was worth taking the sump off I'd check out the pickup but the motor's not digustingly noisy, it's just 500,000km noisy I think.. little ticks and rattles.. fact of the matter is I'll likely be getting rid of this car sometime over the next few months anyway so I'm not sure it's worth taking the motor out and sump off.. I'd do it myself but haven't got an engine crane at home.

Might buy myself a torque wrench and check those pushrods though, I have to do the rocker cover gaskets again anyway.

Sam