Oil pressure

[Fez887]

So as someone who is fairly new to TVR S2 ownership I have a question re oil pressure; the gauge shows 50 when driving, but when I stop at lights and take out of gear the gauge drops off. Is this normal? I know 50-70 is about right but only seems to hold while gear is engaged?

Cheers

[BIG DUNC]

When the engine is warm (or hot) you would expect the oil pressure to drop off at idle.

If it is around 50 psi when running then down to 15 or 20 psi at a hot idle wouldnt concern me.

[phillpot]

Fez887 said:

the gauge shows 50 when driving, but when I stop at lights and take out of gear the gauge drops off. Is this normal?

Start with the obvious..... plenty of oil in it?



Just to clarify...... stop at lights, leave in gear, foot on clutch, pressure stays up? Only drops if you select neutral? ........ Electrical "gremlin" ?

Or drops relative to engine revs whether in gear or neutral? .....This is quite normal


Only way to know what's really going on would be to connect up a capillary (rather than electric) test gauge

Edited by phillpot on Saturday 24th February 06:33

[Dollyman1850]

phillpot said:

Start with the obvious..... plenty of oil in it?



Just to clarify...... stop at lights, leave in gear, foot on clutch, pressure stays up? Only drops if you select neutral? ........ Electrical "gremlin" ?

Or drops relative to engine revs whether in gear or neutral? .....This is quite normal


Only way to know what's really going on would be to connect up a capillary (rather than electric) test gauge

Edited by phillpot on Saturday 24th February 06:33

Or better still switch over to a mechanical gauge I am a firm believer that electrical gauges should monitor electrical and Mechanical gauges should monitor mechanicals

[glenrobbo]

What engine oil is in your S2?

Modern synthetics are great for modern close-tolerance engines, but tend to be a bit too thin for the old Ford V6 Cologne lump, resulting in worryingly lower oil pressure at idle than you would expect.
15 to 20 psi at hot idle is perfectly ok.
5 to 10 psi is rather low.

If this is the case with your S, I would recommend changing the engine oil and filter, and I prefer Valvoline VR-1 Racing 20w50 mineral oil. It has added zddp ( zinc & phosphate ) additives which are beneficial to the valve train.
I use it in both my S1 and S3c and the difference is quite noticeable compared to the likes of Mobil 1


ETA: For further S Series information, go to "Useful Links" on the PH 'S' Series forum.

Edited by glenrobbo on Saturday 24th February 15:22

[Fez887]

Ok so that all seems to make sense. It was serviced by a classic car garage and they probably used modern oil. To confirm they weren’t a TVR spealist but do deal in a number of classics.

Question is; is there a possibility of engine damage if I don’t change the oil? Just to confirm again, it’s not dropping as low as 5-10 so hopefully ok?

As added info, engine temp is not making 90 currently but assume that’s due to cold weather?

Thanks for advice in advance. 👍🏼

[BIG DUNC]

If it doesn't drop below 10 I wouldn't be concerned. Others may say 15.

It should run at normal temperature whatever the outside temp is. It may be that you need a new thermostat if it doesn't get up to normal temp.

I don't have an S so cannot say what the temp should be, but I used to have a Scimitar with the same engine, and that always ran at exactly 90.

[glenrobbo]

Fez887 said:

Ok so that all seems to make sense. It was serviced by a classic car garage and they probably used modern oil. To confirm they weren’t a TVR spealist but do deal in a number of classics.

Question is; is there a possibility of engine damage if I don’t change the oil? Just to confirm again, it’s not dropping as low as 5-10 so hopefully ok?

As added info, engine temp is not making 90 currently but assume that’s due to cold weather?

Thanks for advice in advance. ????

If it's not dropping too low on idle when hot, just change the oil when it's next due.

See this thread for the inside info on the cooling system arrangement and operating temperature:
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[blitzracing]

The old rule of thumb is you need 10 psi per 1000 rpm to be safe,

[nawarne]

Fez887 said:

Ok so that all seems to make sense. It was serviced by a classic car garage and they probably used modern oil. To confirm they weren’t a TVR spealist but do deal in a number of classics.

Question is; is there a possibility of engine damage if I don’t change the oil? Just to confirm again, it’s not dropping as low as 5-10 so hopefully ok?

As added info, engine temp is not making 90 currently but assume that’s due to cold weather?

Thanks for advice in advance. ????

....I did a track day last Sunday in a Caterham with a 'modern' Ford Zytec engine....Even with ambient temps just above freezing, the oil pressure was just off the RED at idle after a 25 minute track session. Engine/car has done about 10,500 miles in total.

I'd have thought 5-10 psi at idle would be fine - - likewise, heed comments regarding accuracy of gauges.

Nick

[Andrew Gray]

blitzracing said:

The old rule of thumb is you need 10 psi per 1000 rpm to be safe,

Yup spot on likewise if i was running at high speed for 30 or 40 miles with my old oil in the Vixen the pressure dropped down below 40 i would back off down to 75 to 80 for 5 to 10 min and back up again i have since switched oil and its far better.
Andrew

[Sardonicus]

If it a Cologne V6 these were never an high oil pressure motor 45/50 hot fast idle 2/3k RPM for example (similar reading when cold) this then dropped to 20/25 hot idle on both 2.8/2.9 thats how they left Ford, unlike the Essex V6 these run at higher oil pressure

Edited by Sardonicus on Thursday 1st March 21:10

[Boosted LS1]

5-10 psi at idle is fine, that's delivery pressure in the galleries. It confirms oil is being pushed along and backing up if that makes sense. Once it reaches your bearings the pressure will be much higher which is the important bit.

[phillpot]

Boosted LS1 said:

It confirms oil is being pushed along and backing up if that makes sense.

No it doesn't

Boosted LS1 said:

Once it reaches your bearings the pressure will be much higher which is the important bit.

How does that work then?

Edited by phillpot on Friday 2nd March 04:56

[Boosted LS1]

^ Have a scroll through this:

https://en.wikipedia.org/wiki/Oil_pump_(internal_c...

Especially the bit titled 'Oil pressure'.

[KKson]

Other option is to tweak your idle speed up a little until you do the oil change. What does it idle at? Typically us Wedge boys set the idle to nearer 900rpm than 750. Oil wise I use Morris Classic Film 20w/50. When I got my 390SE that was running a lighter grade modern semi-synthetic and the oil change brought oil pressure back up to a healthy figure.

[BIG DUNC]

Remember as well that maximum oil pressure is not the be all and end all of everything.

You need sufficient pressure and flow to ensure that there is not abnormal engine wear, but you need other things for this as well, such as clean oil of a suitable grade and viscosity.

As long as the pressure is not excessively low, a few psi here or there is not going to make a huge difference to engine wear. A lighter oil will naturally produce less pressure than a 20/50, but that does not mean that it is not doing just as good a job at lubricating. Whether is it is better or worse for any given engine (modern or old) is a different question altogether.

[Boosted LS1]

^ This.

"As long as the pressure is not excessively low, a few psi here or there is not going to make a huge difference to engine wear. A lighter oil will naturally produce less pressure than a 20/50, but that does not mean that it is not doing just as good a job at lubricating. Whether is it is better or worse for any given engine (modern or old) is a different question altogether."

My turbo engine used to have the oil light flickering when on a hot idle. It used to worry me no end but when I dismantled the engine the shells were like new. Playing with different oil grades made the guage happy (and me) but probably wasn't needed.

I used to import Amsoil or Kennedy 20/50 and with appx 6 litre sump capacity it was an expensive buy. Eventually I switched to Halfords non synthetic 20/50. It was fine, available and cheap.

Edited by Boosted LS1 on Friday 2nd March 11:06