low oil presure trouble RV8

[Ralphh85]

i have almost finished my car now which has a classic rangy 3.5 V8 in it, which covered 144k miles.

the rangy which i drove sounded very sweet, but the oil light did flicker at idle. didnt bother me as it was the right price etc and has served its purpose of proving my conversion has worked.

however after driving the car it seems to have got slightly worse, after warming it up and going for a spin the was coming on if it was under about 1.5-2k rpm.

it sounds fine, but is this likely to cause a bigger problem? the guy i bought it off went on about how they are a low presure engine and its nothing to worry about...

any guesses at the problem? is it just worn out? or oil pump fucked?


cheers.

[Ian Anderson]

Make sure you have mineral oil 20w50 in it

Ian

[Ralphh85]

it has 10/40 probably semi sythetic, i will change oil and oil filter next then.

thanks for the info!


Ralph

[ChrisJC]

Ian is dead right, particularly on a tired old engine. 20/50 is a must.

Chris.

[DEVONMAN]

Oil light switch has also done 144K so worth a check as well as put in 20/50 oil
Regards Denis

[Ian Anderson]

And for the first batchI'd use the cheapest oil I could find
Tesco's used to do a 5l bottle for abour £6


Run it for a couple of hundred miles to check if it works or needs stripped down

It will also flush out a pile of crud that is no doubt inside the engine

Ian

[RoverP6B]

Hello Ralph,

I would certainly change the oil warning light switch. Having one come on while the oil pressure is fine is quite a possibility.

They are supposed to light when the oil pressure falls to 9psi plus or minus 1 psi and remain on until such time as the pressure rises.

Ron.

[kstrutt1]

And for the first batchI'd use the cheapest oil I could find
Tesco's used to do a 5l bottle for abour £6


Run it for a couple of hundred miles to check if it works or needs stripped down

It will also flush out a pile of crud that is no doubt inside the engine

Ian

Asda do 20/50 for £6 a gallon, I have this in the engine I have just built using parts of my old recon engine(failed with loose liner) and a secondhand one, bottom end has done around 80K and the oil pressure is around 15psi at 600rpm idle, plan is to use it as a flush and run it for 500 miles or so then change to something a bit better.

Kevin

[mgbv8]

I use the Asda 20/50 for flushing as well mate!

I'll be running 2 gallons through mine soon on a new filter before chucking the Halfords Classic 20/50 in on another new filter.

I normally run the engine for an hour on each gallon. Then drop it out while hot and bung a fresh gallon in on the old filter. Then change the filter and stick the Halfords stuff in

This is the procedure I follow at the start of the race season. I change the oil every 25 passes. And do an oil and filter change around July and November each year.
My engine internals look shiny and new at any time of the year

[Graham B]

I too suffered with low oil pressure at tickover when hot (around 5-10psi) it picked up well enough with revs, but seemed frighteningly low to me on tick over having been used to a straight six Triumph.
I have been told by an "Expert" in Rover V8's that these engines have low pressure high volume systems, which is why they didn't put oil pressure gauges is some of the cars fitted with this engine as they thought that folks used to a decent oil pressure would worry!.
I have also heard stories of people running V8's in Range Rovers for years with low pressure with no problems.

I have tried putting new oil pump internals in, a tadpole pressure relief valve (aparently the cylindrical ones can stick) and a higher pressure relief valve spring. I also renewed the mains and big ends (still standard but getting close to their limits).
The biggest boost to pressure I got was when I changed to 20W50, I was running 10W40 and it was like water compared to 20W50.

Tick over at present is a more respectable 20psi although I have not had chance to get her really hot yet as I'm not back on the road till the end of the month.

Cheers
Graham

[DaveEFI]

I too suffered with low oil pressure at tickover when hot (around 5-10psi) it picked up well enough with revs, but seemed frighteningly low to me on tick over having been used to a straight six Triumph.
I have been told by an "Expert" in Rover V8's that these engines have low pressure high volume systems, which is why they didn't put oil pressure gauges is some of the cars fitted with this engine as they thought that folks used to a decent oil pressure would worry!.
I have also heard stories of people running V8's in Range Rovers for years with low pressure with no problems.

I have tried putting new oil pump internals in, a tadpole pressure relief valve (aparently the cylindrical ones can stick) and a higher pressure relief valve spring. I also renewed the mains and big ends (still standard but getting close to their limits).
The biggest boost to pressure I got was when I changed to 20W50, I was running 10W40 and it was like water compared to 20W50.

Tick over at present is a more respectable 20psi although I have not had chance to get her really hot yet as I'm not back on the road till the end of the month.

Cheers
Graham

The SD1 version certainly runs at low pressure. But it's designed to - the mid point in the gauge is only 30 psi. And at lowish revs won't even make that if using 10-40 - the recommended oil. But so saying the warning light shouldn't ever come on with the engine running.
As regards using thicker oil, it may well give a reassuringly higher presure - but the job of the oil is to cool and clean as well as lubricate, so the faster it circulates the better? And that might well help prevent the RV8's bete noir - camshaft wear.

I just ignore the gauge on my SD1 - at over 150,000 miles it's still quiet and uses no oil.

I did try fully synthetic 0-40, which showed even lower pressure. But gave up on that due to oil leaks.