Weird Oil Pressure Problem, come have alook....

[cliolord]

Scratch your head at this one then lads...

Oil pressure on cold start at idle 2bar, oil pressure at 2000rpm on when cold 2.3bar, 2500rpm when cold 2.3bar.

Oil pressure at 70*C on idle 2bar, at 2000rpm 2bar, at 2500rpm 2.3bar

Oil pressure at 90*C at idle 1bar, at 2000rpm 1.5bar, at 2500rpm 1.5bar

Oil pressure at 100*C at idle 0.5bar, 2000rpm 1bar....

Abnormally low so this is what I have done so far....

Fitted 3 Oil Pumps (and fitted 3 washers to boost relief valve pressure), replace oil filter, replace oil pump sender unit, fitted a race tech mechanical oil pressure guage and got 35psi on idle from cold (which was fitted to oil pump housing). ANY IDEAS AT ALL? :roll:

[drsmith1979]

mine isnt too different when really warm, low pressure on idle but raises as you lift the rpm, for me its just the oil getting too thin when hot and thus reducing pressure, but remember as oil man says, less pressure means easier flow, more pressure, less flow due to the relevant viscosities

[cliolord]

But this pressure is just not adequate :cry: The guage moves very slowly up and thats on the mechanical guage too

[Lunner]

maybe you're loosing pressure through a leaking seal somewhere?

[2 live]

what oil u using?

[cliolord]

its not the oil but im running 10w40 semi. it was the same with mineral oil 15w40. I am thinking of dropping sump pan and using pastiguage on the bearings just to check tollerances? I cannot think of anything else at all

[Lunner]

Yeah but what brand of oil?

[Matty86]

My pressures dropped like that when I topped up with halfords 10w40 semi

[2 live]

castrol has tendancy to give poor pressures/temps.

castrol edge is the worst oil iv seen for this. certian oils will give spurious results on the press/temp guages

[robi1000]

Will Elf Excellium LDX 5W-40 give good results?

[Lunner]

I've never had any problems with Shell Helix 5W40 fully synth or silkoline Race 5w40 fully synth

[richy]

Will Elf Excellium LDX 5W-40 give good results?

thats what is recommended for the 1 7 2/1 8 2 etc, i run both my 1 8 2 and 16v on it, never had a problem with oil pressures etc too

[cliolord]

I really dont think that by replacing my oil with 60quid oil it will rise by 4bar lads :roll:

[richy]

£60 lol i dont quite pay that! but anyway...

is this your new t/b'd engine~?

have you tryed taking a reading from were the pressure sensor next to the filter is aswell? im guessing the place you took it from is the sensor fitting at the back, just to see if it varies much?

[cliolord]

i havent taken a reading from the front of the block no, only the back. But this should be accurate, i cant see why it would read wrong? If it reads wrong, the pressure is wrong how can it be blocked?

[richy]

i was just thinking that the sensor at the front is what trips the warning light on when the oil pressure is to low etc as you havent mentioned if its on, i know the reading off the back should be accurate as its were renault state to take a reading but what if the outlet to the sensor is blocked and not allowing you to take a good reading?

as you have said you have already tryed 3 oil pumps and uprating the pressure relief valve spring with washers, so that shouldn't be a problem, but before you go taking the sump off and checking the clearences id just double check that theres nothing causing you to get the incorrect reading

also you tryed a geniune oil filter as i know a few ppl have had problems with non gen filters.

[cliolord]

it has a renault oil filter, I think the pressure switch on the front is an M12 fitment where as I have an M10 fitment for the back :roll:

[richy]

im guessing you didnt get a kit then? could you get a adapter for it?

[cliolord]

yes but will have to wait a week. Its a proper cockpit guage

[stan]

I didnt deam the pressure as abnormal once on the dyno, or on the road...neither did Jonathon. Its running the same/better pressure as most F7R's mate.....

[cliolord]

but it use to hold 4.5bar at 100*C at 4000rpm on the standard renault guage i dont want it going pop it will be a massive blow. agreed that it shows no signs what so ever of low oil pressure but the guage readings are putting me off of driving it...you could say I was scared. It goes so well now that I dont want it to be taken off the road again. I have a second car now which is a Mini 998 resprayed in williams blue with gold wheels :twisted: so i use that for normal transport. The clio is a weapon and it needs to stay on attack form

[stan]

youve said it yourself, its not showing signs of low oil pressure...
it done a day on the dyno, plus 500-600miles on the road, and its still fine.

Out of intrest, this new sensor, there is it taking voltage from??

[2 live]

but it use to hold 4.5bar at 100*C at 4000rpm on the standard renault guage i dont want it going pop it will be a massive blow. agreed that it shows no signs what so ever of low oil pressure but the guage readings are putting me off of driving it...you could say I was scared. It goes so well now that I dont want it to be taken off the road again. I have a second car now which is a Mini 998 resprayed in williams blue with gold wheels :twisted: so i use that for normal transport. The clio is a weapon and it needs to stay on attack form


got a set of 10" revolites with decent tyres if u intrested mate lol.

[cliolord]

youve said it yourself, its not showing signs of low oil pressure...
it done a day on the dyno, plus 500-600miles on the road, and its still fine.

Out of intrest, this new sensor, there is it taking voltage from??

its a mechanical guage, runs with oil to the guage no voltage needed...i just want to be sure :D

[Yanoo_]

castrol has tendancy to give poor pressures/temps.

castrol edge is the worst oil iv seen for this. certian oils will give spurious results on the press/temp guages

I used these oils before:

Chevron 10w-40 - average performance, but at high temp less or none indicated pressure at idle !!! (at 80 C 0-0.2 bar, but the oil pressure warning lamp not light)... so I changed this oil fast... avoid it!
Castrol RS 10w-60 - high performance, at high temp higher pressure at idle (0.8-1 bar) when the oil is new but if becomes old(er) less pressure at idle
ELF Competition 10w-40 - the worst oil what I ever used... bad engine sound and at 60 C (idle): no indicated oil pressure... like the Chevron... Chevron was a bad oil too, but at least with that one I had oil pressure at 60 C... so I changed this awfull oil after 150 km
Castrol Edge Sport 10w-60 - high performance, higher oil pressure on every RPM and every temp (0.2 + 0.5 bar), the oil pressure at 80 C and at idle is about 1 bar (after 4000 km)... I think it's the best oil nowadays (IMO)

(I'll change the oil pump at the next cambelt change)

[arj256]

Having a quick look on the net i came across this:

"Another disadvantage to most forged pistons is the higher coefficient of thermal expansion. They have to be capable of running the tightest clearances when the combustion chamber is at its hottest, and that means that for anything besides full throttle like normal cruise and cool temperatures they are going to have increased piston to bore clearances."

So if this statement is true then your engine is fine.
Do the pressure tests with higher rpms and see what you get with the temperature / pressure relation.
Are you burning much oil?

[stan]

Piston/bore clearances arent effecting oil pressure though...

and no, its not burning oil.

[Wobba]

What are the signs he would have of low oil pressure though?

I have a similar problem but have not investgated yet and seem to have no adverse problems so far...

[eternalife]

So would anyone care to venture an educated guess at the solution?
What are the probable causes?
What would need to be checked / fixed?

[Laine_16v]

A blockage.

[Allan]

maybe do an engine flush and new oil, just to be sure ?

[eternalife]

A blockage.

Dont think a blockage is feasible - doubt Engine could sustain the 500-600miles + the dyno day.

Also personally (sorry to partly hijack thread) not looking for one word answers - need theory, thought n practicality explained (see bold educated :wink: ) in order to understand why an engine would perform in this manner

[stan]

The fact that it sustained these miles and the mapping session instills confidence that there is no terminal problem....for me anyway.

However, usually LOW oil pressure can be caused by the bearing running clearances being excessive, or inadequate pump.

[seanofnp]

My pressure drops right low much like this when upto temp.

I was told it was normal ish for a F7R?

[stan]

Its quite normal mate....most run around 2-2.5bar when hot at 4000rpm upwards.

[Tommo]

castrol has tendancy to give poor pressures/temps.

castrol edge is the worst oil iv seen for this. certian oils will give spurious results on the press/temp guages

I used these oils before:

Chevron 10w-40 - average performance, but at high temp less or none indicated pressure at idle !!! (at 80 C 0-0.2 bar, but the oil pressure warning lamp not light)... so I changed this oil fast... avoid it!
Castrol RS 10w-60 - high performance, at high temp higher pressure at idle (0.8-1 bar) when the oil is new but if becomes old(er) less pressure at idle
ELF Competition 10w-40 - the worst oil what I ever used... bad engine sound and at 60 C (idle): no indicated oil pressure... like the Chevron... Chevron was a bad oil too, but at least with that one I had oil pressure at 60 C... so I changed this awfull oil after 150 km
Castrol Edge Sport 10w-60 - high performance, higher oil pressure on every RPM and every temp (0.2 + 0.5 bar), the oil pressure at 80 C and at idle is about 1 bar (after 4000 km)... I think it's the best oil nowadays (IMO)

(I'll change the oil pump at the next cambelt change)

I agree yanoo, I use Castrol Edge Sport 10w-60 and the pressure readings are spot on. It used to idle at almost zero pressure when using Helix 10w-40 when hot, now it sits at 1 bar at idle, and 4+ bar when on the move

[eternalife]

Is oil pressure linearly or exponentially related to rpm?

[stan]

Exponential. why?

[Allan]

is 10w 60 not a little thick for the engine ?

i though a 40 was the recomended

[MAXIBOY]

depends on use....

15w/40w is suggested

but since things have moved on

i use 5w/40w fully synthetic but because of the turbo....

in a normal 16v i would use a quality semi or fully synthetic as its a better bet than using a cheap oil

still you pays your money and makes your choice

[Tommo]

is 10w 60 not a little thick for the engine ?

i though a 40 was the recomended

If I remember correctly the 10w bit is the cold viscosity (W means winter), so a 10w-60 has the same cold viscosity as a 10w-40. This means cold starting oil flow will be the same on a 10w-60 as a 10w-40. The 60 is the viscosity at 100 degrees meaning the oil is more stable at higher temperatures, which suits the more enthusiastic fast road and track driver. It's the perfect performance oil grade imo, although I'm no expert!

[Purple]

is 10w 60 not a little thick for the engine ?
i though a 40 was the recomended
I tried 10W-60 (Liqui-Moly) on the Williams once and, frankly, I don't think it feels any more sluggish than 50 grade. Just too expensive to use regularly.

[Yanoo_]

is 10w 60 not a little thick for the engine ?

i though a 40 was the recomended

If I remember correctly the 10w bit is the cold viscosity (W means winter), so a 10w-60 has the same cold viscosity as a 10w-40. This means cold starting oil flow will be the same on a 10w-60 as a 10w-40. The 60 is the viscosity at 100 degrees meaning the oil is more stable at higher temperatures, which suits the more enthusiastic fast road and track driver. It's the perfect performance oil grade imo, although I'm no expert!

Yes! You are right!
The kinetic viscosity of an 10w-60 engine oil at high temperature is 21.9-26.1 mm2/s (100 C) (rather stable, it does not become very "thin")

The other warm kinetic viscosity values:

http://www.renaultclub.hu/photos/yanoo/szereles/22/pic01.jpg

I've written a documents about the engine oils for the Renault Club Hungary members. It contains the description of the main ingredients, additives, viscosity, how does it work etc. If you think I'll translate it.

[Tommo]

is 10w 60 not a little thick for the engine ?
i though a 40 was the recomended
I tried 10W-60 (Liqui-Moly) on the Williams once and, frankly, I don't think it feels any more sluggish than 50 grade. Just too expensive to use regularly.

I order direct from Castrol, works out the same as any other quality fully synthetic and free delivery too

[G33R7]

i'm now running on 10w40 half sythetic oil. Someone told me "ones you used half synthetic, you should hold to that. its not good to switch to full synthetic."

is this bullshit?

my oil pressure at 100 degrees is also 0 bar and i would like to try castrol edge 10w60 now.

[G33R7]

nobody knows?

[Allan]

they probably ment at the same time, rather then one after each other

[eternalife]

back the thread topic...

http://www.williamsclio.co.uk/forum/viewtopic.php?t=27403

Pressure in the vid doesnt seem to rise at all (be it exponentially or linearly). Can this be explained?

[northy]

that should defo rise with the rev increase there.

What happened on the second run around around 36 / 38 seconds ?

[Wobba]

is 10w 60 not a little thick for the engine ?

i though a 40 was the recomended

If I remember correctly the 10w bit is the cold viscosity (W means winter), so a 10w-60 has the same cold viscosity as a 10w-40. This means cold starting oil flow will be the same on a 10w-60 as a 10w-40. The 60 is the viscosity at 100 degrees meaning the oil is more stable at higher temperatures, which suits the more enthusiastic fast road and track driver. It's the perfect performance oil grade imo, although I'm no expert!

Yes! You are right!
The kinetic viscosity of an 10w-60 engine oil at high temperature is 21.9-26.1 mm2/s (100 C) (rather stable, it does not become very "thin")

The other warm kinetic viscosity values:

http://www.renaultclub.hu/photos/yanoo/szereles/22/pic01.jpg

I've written a documents about the engine oils for the Renault Club Hungary members. It contains the description of the main ingredients, additives, viscosity, how does it work etc. If you think I'll translate it.

If you can translate it yanoo I think it would be an interesting read. Not sure if it has been done before here...others may know.

[eternalife]

that should defo rise with the rev increase there.

What happened on the second run around around 36 / 38 seconds ?

Exactly - Was thinking maybe the fact that the pressure was staying constant would help people in the know here diagnose the problem more accurately..

[white16valver]

that should defo rise with the rev increase there.

What happened on the second run around around 36 / 38 seconds ?

Exactly - Was thinking maybe the fact that the pressure was staying constant would help people in the know here diagnose the problem more accurately..
Just as a thought, and perhaps I'm being dumb, but is it just a sticky needle?

Mine sticks between about 2 and 4 bar, so it'll rise from the bottom when cold to about 3, then when you tap it to free it it will rise to 6. And when it's hot you can come off the accelerator and come to a stop and it'll still be stuck at 3, so you tap it and it comes back down to 0.5bar LoL

I'm guessing it's the needle anyway as it fixes itself when you tap it! :lol:

[Laine_16v]

that should defo rise with the rev increase there.

What happened on the second run around around 36 / 38 seconds ?

Exactly - Was thinking maybe the fact that the pressure was staying constant would help people in the know here diagnose the problem more accurately..
Just as a thought, and perhaps I'm being dumb, but is it just a sticky needle?

Mine sticks between about 2 and 4 bar, so it'll rise from the bottom when cold to about 3, then when you tap it to free it it will rise to 6. And when it's hot you can come off the accelerator and come to a stop and it'll still be stuck at 3, so you tap it and it comes back down to 0.5bar LoL

I'm guessing it's the needle anyway as it fixes itself when you tap it! :lol:

Its been tested with a mechanical gauge.

[cliolord]

that should defo rise with the rev increase there.

What happened on the second run around around 36 / 38 seconds ?

that is a nasty motorist on the track getting in the way :lol: