Dip stick woes

[Touching Cloth]

Ok this is doing my head in, please bear with me.

Coming back from Le Mans I had the oil pressure dipping on left hand turns, cue heart attack. Anyway checked it (hot unfortunately but no choice) and whilst oil was present on stick it seemed low so stuck just over 1L in. Pressure back to normal and all appeared fine again.

Checked day after I got back and it appeared again to be on the min level of the dipstick, slightly surprised (and worried) about this but attibuted further heavy usage (had only done maybe 350 miles since the above top up) down to having used 0w40 stuff purchased in France and it being too thin, usually has Mobil Motorsport 15w50 as recommended by my man who can, but could not get this in France. Finally managed to source a 4l container of 15w50 yesterday, checked again and still showing low so popped in another litre, now proving really hard to gauge from dipstick what the level was but looked ok. Took it for a drive and pressure was 50 at start up and just sub 40 at hot idle (sure it used to be 60-70 at start up but as hot yesterday guessing the oil is not going to be so thick when engine cold hence not hitting the peaks).

So to today, decided to do the dipstick out overnight thing and gave it a check first thing just to be sure, came out just perfect on the side with the marks, happy bunny, went to put it back in however and noticed the rear side was oiled up right up to shoulder bit where it joins the wirey bit (technical terms). Now worried I have overfilled as not sure which side to trust!!!!

Someone please tell me that if I had overfilled I would have seen much higher pressures/possible smoking and that it is probably ok and just a crap dipstick.

S.

Edited by Touching Cloth on Saturday 1st July 11:23

[350matt]

Overfilling will not increase the engine oil pressure

What it will do is cause aeration of the oil at high rpm and power loss as teh crank has to constantly plough through it.

If you're really concerned about the oil level I'd suggest draining it all out and then measuring the 6 litres it take to fill it back in again.

The dipsticks are notorously unreliable and I find the leaving it out overnight method work best.

I also found on mine that I as getting oil pressure drop -outs (seen on gauge ) under heavy braking despite purposely filling over the top mark
This has since been remedied with an Accusump for the time being but I plan to baffle the sump better ( apparently its already baffled to some extent) when I strip the engine

Matt

[dinkel]

At overfill you'll see stuff in the oilfilter

[tophat]

My dipstick is HUGELY unreliable and I have taken to roughly guaging by pressure. I spoke to a mechanic about it and he commented that the smoky exhaust phenomenon only occurs when you're far far too full.

[GreenV8S]

350matt said:

Overfilling will not increase the engine oil pressure

Underfilling it can cause the oil pressure to drop though, because the oil spends less time cooling down in the sump.

[thegreengoblet]

Sorry I can't really offer any advice re the oil pressure.

Just thought I'd mention that my dipstick level is always messy(ish) on the level indicator side and I only get a clear line on the unmarked side. I've ignored Fernies advice to put in thicker oil and have been topping up with 0-40 and this defiinitely helps to get a good reading - the thicker oil just seems a bit to gloopy and pulling and dipping causes both sides of the stick to get messy especially as you have to turn the dipstick to get it flush in the dipstick holder (I only turn the dipstick enough to get it flush - I don't perform the last 1/4 turn to lock it in). I too have found leaving the dipstick out helps, but I only need to leave it for 10-15 minutes to get a reading.

[simonsparrow]

350matt said:

This has since been remedied with an Accusump for the time being but I plan to baffle the sump better ( apparently its already baffled to some extent) when I strip the engine

Matt

Was it hard to fit and how well does this work? I've thought about doing this, but never got round to it.

[satman]

Whilst i agree that keping the engines oil levels regularily checked and topped up, the oil pressure fluctations can be caused by a 'weak' oil pressure relief spring. Change mine every service, costs peanuts to buy, and maintains consistant oil pressure readings!