Valver low oil pressure:help appreciated!

[Ben H]

When my engine is hot, the pressure needle sits at about 0.25Bar these days. It used to sit at about 0.75Bar on warm idle.

The engine was rebuilt at 72,000 miles after a cambelt snapping and is on 104,000 now. Would I be right in thinking that the oil seals would have been replaced at that time, so its unlikely that the seals are causing the low pressure?

I asked my garage to check this a few months ago and they said the sump was leaking slightly, but not a lot. The engine is also using more oil than normal at the moment too.

What else could it be and is it something to worry about?

Help appreciated.

 

[Fatherted]

what grade of oil are you using & how much oil is being used ??

also what make of oil filter is being used ?

 

[night.icon]

could be just a faulty sensor as mine sits high compared to other valvers i have been in

john

 

[Ben H]

Ive got to admit that at the moment Im using bog standard Halfords 10/40 semi-synthetic (I know, I know!). But although the quality may not be the best, it is the oil grade that the factory recommended. The filter is genuine Renault. Id say its losing about a litre every 500-1000 miles. Losing a litre every 1000 miles is normal, but every 500 miles suggests something is not quite right. The oil pressure is definitely a lot lower than it used to be.

Ive checked my bills and the valve/oil seals were done when the engine was re-built 30,000 miles ago. So maybe it is the sump gasket? Would a small leak be enough to bring the idle pressure down from about 0.75Bar to 0.25Bar?? Could be a faulty sensor, but Id have thought that it would have always given a funny reading instead of just changing recently if that was the case.

Cheers all - any more help is appreciated.

 

[funkimic]

you could try putting in some fully synth and see if that helps. when i bought mine it had been using castrol bogo stuff for the past 3 years and my oil pressure was low. just under 0.5bar. i changed the oil for fully synth silkolene and the oil pressure at revs and idle went up. at idle it now sits at 1bar and 3500rpm its just under 4bar at 80C. might be worth a try.

 

[BenR]

oil loss is always high on our engines. The under piston bore sprays means alot fo oil is burnt up in teh breather system as it moves about as vapour.

10w40...........oil is reccomended but isnt biblical, i use 15w50 as they run so hot that a higher vis oil is needed, and you should choose your oil in regards to your environmental and engine running temps really.

Oil pressure being low means nothing at the moment since you havent said at what temp. they should be 1bar at 1000rpm and 3bar at 3500rpm @ 80C factory spec.

Mine meets this, but as soon as you get high oil temps the pressure drops as a natural occurence......i run about 110deg most of the time in mine so an oil cooler is making an appearance. 120 C on track means almost no pressure lol.

The sump problem wont affect pressure as its not part of the pressurised channels. Oil stem seals i guess your talking about can lead to oil consumption but they are generally good and dont let much past as they have a small spring round them.

 

[The Doors]

I had a similar prob some days ago (posted in here too) solved with a simple oil change, and probably related to an oil additive used the last time.

Adriano

 

[Bennyboy]

same here, the gauge on mine started reading low then dropped to zero and stayed there so drained the old oil, poured a little bit of petrol in just to wash any crap out of the sump, new oil back in, turn the engine over for a while without the spark plugs in. start it up and hey presto, oil pressure back to normal.