oil pressure

[swordfishdani1960]

my oil pressure was low ,18 quid cheap shite ,i change it every 4 months and filter
new oil in ,more expensive oil. pressure back up
old oil removed 4.5 litres is this the norm
in the 16 years I've had this car , never to use any oil

[saabfast]

Is it a 2.0 or V8? I use good old 20/50 'Classic' from Halfords or a local factors, look like the old Duckhams Q20/50 of years ago. It runs OK but when very hot after a long run the pressure drops to around 20psi at idle. I thought the oil pump might be worn and changed it but it made no difference at all. I now have STP in the oil and it is a little better, dropping to 23-25psi. Runs at 35-40 so not too bad. One day it might need the bearings done.

[Hasbeen]

I gave up using oil pressure as a warning of impending doom many years ago. I was driving a mates Lotus 20 formula junior, with a Cosworth 105E Ford Anglia engine. It had all the right stuff for the day, forged crank rods & pistons etc.

When it suddenly lost power about half a kilometre from the pits, I stuck it in neutral, & coasted in. The crew checked the thing right through the rev range, up to 8000, & could find nothing wrong. It was holding 65 PSI oil pressure from idle to 8000, obviously controlled by the relief valve setting.

They suggested I go out again, but I couldn't see the point being 2 laps down by then. This was just as well. On stripping we found on one big end all the bearing material had disappeared, & the steel shell of the slippers had welded itself into a complete ring of steel, sitting around the crank. It was bright blue, & had obviously been very hot.

If a bearing can be almost not there, without changing the oil pressure, I don't think loss of oil pressure is likely to give you engine saving warning.

If yours is low, try increasing the relief pressure valve spring tension or length.

Hasbeen

[swordfishdani1960]

Put it down to cheap motor oil ,Halfords / 20/50 is more suitable for my Tr7 which have been the choice for years ,best spending extra on good stuff .i thought by changing my oil every 4 months for a cheaper oil would be all right ,luckly am doing a 1000 miles every 4 months ,as you no takes 10 mins to do an oil change ,have been doing this for years ,thats why my engine is top condition ,the oil is the price for a round a beers ,the low oil pressure is down to poor quailty oil ,that thins out so all is good, no more crap oil , thanks

[Howard_B]

I just had my engine bottom end rebuilt (110k Miles) when I had to have the engine out due to a burnt out valve. Despite the decent oil pressure the shells had almost gone so the valve problem was a lucky escape.

[sonscar]

If you had only the light you would be happy with anything over about five pounds as it would be out.The reading is not so important as is it where it normally is?sudden rise or fall may signal impending doom.Is there more of a different noise?Enjoy,Steve..

[Beans]

Many years ago, the original engine of my DHC started knocking slightly when cold @ 200.000+ km.
When it worsened after a few months I decided to replace it with a freshly built spare engine.
This was probably caused by an oil filter seal collapsing during a run.
I noticed a screeching sound from the engine and switched of the engine just when the oil warning light switched on

After stripping the original engine it turned out all big end bearings were on their copper lining.
But the crankshaft had survived and only needed very light machining.
This engine was rebuilt (to Sprint spec with a few extra horses) and has now covered well over 110.000 km since rebuilt in 't Kreng
When hot the oil pressure still sits slightly above 30 psi on idle (@ ±900 rpm)

[dursleyman]

I was out in my "new" FHC last weekend on the Lombard Rally Bath 2018. This is a classic car run but with the emphasis on retracing some of the Lombard RAC Rallys from the 1970s/80s. The entry list was full of famous names from that era driving quite a lot of the old ex-works cars. Stig Blomquist, Jimmy McRae, Tony Fowkes, Dai Llewellyn etc etc etc
My car was only ready the day before and I had not had the chance to drive many miles so was a bit concerned when the oil light started to flicker on tickover as we waited at the start. It went out as soon as the revs increased so with 200 miles to go we could only set off and keep an eye on the light.
At the start of the Longleat House "stage" the light was flickering again. Soon after, at the Cricket St Thomas "stage", it refused to go out at all but with no sounds of distress from the engine we kept going. Our conclusion was that it must be a faulty switch. Later when we were able to really drive the car hard on the Wiscombe Park Hillclimb and the Porlock Toll Road it ran well and got us home safely the next day.
A new switch has now been fitted and all seems well - but I have no idea what the oil pressure really is!