GAUGE READING WHILE DRIVING AND IDLE

[sup3rm4n]

Hi Everyone,

Hope you are well!!

Can someone please guide me what my Oil Pressure, Battery and Rev Counter should be reading when starting up/idle and while driving on my 88 Esprit NA.

Thanks

Edited January 19, 2011 by sup3rm4n

[Sparky]

Hiya.

Oil pressure reading will be different from car to car, but as long as it's pretty constant on idle and increases with engine speed, that's OK. It's normal to decrease with engine temperature increase.

Battery should ideally read between 13.5 and 14 volts, don't worry unduly as long as it's above 13 with no major items switched on.

Idle should be around 950, but on startup will vary.

Finally, don't trust the gauges 100% - plugging dedicated testers in may do a better job!

[sup3rm4n]

Hi Gary,

Thanks for your reply, on a cold morning startup, after turning the key the revs are at 450-500, I have to put my foot on the accelerator to about 1000 revs to keep it turning over otherwise it drops to 0 revs and conks out, is this normal?

When it warms up (after 5 minutes), it then stays at about 900-1000.

Edited January 19, 2011 by sup3rm4n

[Sparky]

Sounds about right, with no choke on a cold engine. Do you have a working manual choke? it's a fairly complex arrangement that rarely works well.

[sup3rm4n]

Hi Sparky,

Sorry for the delay been off my PC for a while, Yes I have a manual choke which I have just started using, I pull it out all the way and then start the engine and the revs after a minute reach 1,500rpms, so I then push the choke in about 40% and then drive off, 5mins into driving I then put the choke in fully. Am I doing this correctly?

Also, I have noticed on cold start up, on idle the oil pressure is at 5 and with acceleration it goes past 5 into the red. After 15 minutes of driving (keeping the revs no more than 3000rpm), the oil pressure does eventually move to just below 5 on aceleration and on idle it reads 2. Is this normal?

Please let me know

Thanks

[andydclements]

That's a bit high, there isn't a pressure relief valve so that cannot be stuck closed.

What oil are you using?

[sup3rm4n]

Hi Andy,

Thanks for getting back to me, I am using 20w/50 as the manual recommends, BUT very weirdly, I think I might have resolved it - My driveway is on an incline and the last couple of months I have been parking my car with the nose facing down, in which time I got the high oil pressure from start. BUT the last couple of days I parked the car with the nose facing up and since then the oil pressure has been around 4 1/2. Is this coincidence?

[sup3rm4n]

Ok, weird!!! The oil pressure is going in the red above 5 again!!!! It is happening when I go above 2000 RPMs.

Can the change from regular unleaded to high octane cause this?

[andydclements]

It shouldn't have any effect.

Re the effect of nose up or nose down. beyond the time to initial pressurisation it should have no effect on the reading, unless the gauge itself is faulty.

[sup3rm4n]

With it in the red above 5, can this damage the engine?

[andydclements]

I doubt the pressure is as high as the gauge indicates, as it doesn't have a pressure relief valve to get stuck these engines run at maximum oil pressure normally. Unless something has become stuck in an oil way reducing flow so increasing pressure I can't think that the gauge is seeing higher than "new" oil pressure.

Can you get an old mechanical gauge and tap it in the system near the engine bay and compare the two readings?

[fflyingdog]

I would definitely check your pressure, as a blocked oil gallery can cause a higher pressure BUT lower oil volume.........or you could just have a broken gauge or sender unit.

Nick S4s

[Mike6]

Hopefully its just an inaccurate guage as mine reads about 5 on start up drops back when hot. If it drops to 2 on tickover as mine does I doubt you would have any blockage problems. If the pressure builds up to much I imagine the oil dipstick would pop up. When accelarating my reading shows about 4.5 but around 3 or 4 when driving along at about 50mph.

At some point I am going to drop the sump and check the oil strainer but otherwise you may just have a very healthy engine