Oil pressures

[WhyTwo]

I've had my Cerb around 6 or 7 weeks now and am concerned about the oil pressure readings so would be grateful if anybody could advise if these are correct or what to do if not.

On start up the pressure goes straight to about 70. It then remains at 70 either at idle or under load for around 10 - 15 minutes of normal driving, no real use of the loud pedal. Following that it will read around 50 at hot idle, 60 under load up to around 2K revs and then 70 - 75 from 3k revs upwards.

I'm convinced this is not correct. Should I be worried?

Oh and it's a late model 4.2 (2004)

[Gazzab]

Sound like excellent readings to me. The hot idle should be closer to 40 I would suggest but the key thing is you have good oil pressure and that it moves down as the car warms up but is high again under load etc....

[Gazzab]

Oh and dont forget that you should keep the revs to under 3K until the car is warm (eg 5 miles / 15 mins driving) and under 4K revs until the car is hot (eg 25 mins into driving). Then you can rag it.

[big_treacle]

Sounds similar to mine since engine rebuild. Was lower before. I would say your pressures are good

[WhyTwo]

Thanks guys. I guess I was just concerned it was so high on start up and didn't really drop much even after 15 mins of driving. Maybe I was expecting it to go down to 40 or maybe a bit lower at idle once warmed up.

What oil should I use? 5w 40?

[itiejim]

Oil pressures seem on the highish side of typical, definitely nothing to worry about.

Having said that, I am convinced that 50 PSI at hot idle is massive overkill and indeed counter-productive. I'm sure we'd all spend less time chasing oil leaks if the engine ran more sensible pressures - and probably create more power too.

[skidoo]

i have an early 4.2 and hot idle 9-950rpm is 20psi and shoots up to 55-60psi on any throtle, cold idle 50psi 70psi repactivly ive had no problems

[C3BER]

35 at 2000 revs is your min.

[itiejim]

C3BER said:

35 at 2000 revs is your min.

That's probably a good indication a health in an AJP engine, but the generally accepted minimum is 7psi / 1000 rpm. If you look at a lot of RV8 speed six or even XK engines they run very close to this, particularly at tickover.

[C3BER]

TVR recommend for their 6/4.2/4.5 engines oil pressure of 35 psi at 2000rpm as a min. I'm not sure what any other engine should be.

[itiejim]

We agree then

[aide]

skidoo said:

i have an early 4.2 and hot idle 9-950rpm is 20psi and shoots up to 55-60psi on any throtle, cold idle 50psi 70psi repactivly ive had no problems

I bought a Cerbera in May and have spent more time gawking and worrying about the oil pressure gauge than I'm prepared to admit I did come across one thing that helped me up pressures by ~5 psi though. If the oil pressure release spring hasn't been changed in a long while having a new one fitted will definitely increase the hot idle and hot on-throttle pressures.

Edited by aide on Monday 25th July 23:34

[C3BER]

itiejim said:

We agree then

Well as long as you include the speed 6