Engine Startup - rev or idle?

[malmoy]

1990 1.6TD - Engine runs fine and all ok.

On start up from cold the oil light takes 10 to 15 seconds to extinguish when left to idle.

So my question is - should I let it tick over while the oil pressure is obtained or give a slight rev to get the oil pressure up quickly?

1. Idle, no sudden stress, but oil may take time to get to camshaft etc.
2. Rev, extra load on crank and cam, but at least oil pressure is up.

Thanks, Mal.

[kevtherev]

I think you should address the oil pressure problem at start up, rather that pussy footing with it.
when was it last serviced?
what oil are you using ?
Whats cold start tick over speed?
Change the sender they're only a few quid.
have a pressure gauge fitted and find out what's going on.

Oil pressure should extinguish a warning light immediately on startup as the oil is cold and viscous.
The low pressure light comes on at 0.3 psi
on cold start up you should get 50+ psi

I think your senders shagged

[malmoy]

Thanks Kev,

I've double checked.

Van starts first turn from cold, then 5 seconds for light to go out. Idle, steady at about 650, assuming rev counter is accurate (?) this seems low. I'll get pressure and idle speed checked. 0.3 psi seems low for an oil light, I would have thought 5-10 psi, before it turns the light out?

Not an issue when warm as it takes a few turns to start so light goes straight out.

Still would like to know if there is a definitive answer about revving or idling?

Mal.

[kevtherev]

Still would like to know if there is a definitive answer about revving or idling?

Mal.

That's my point, you shouldn't have to think about it.
But until you fix it.... rev it
lights mean.. warning ..damage!...

Oh yeah, it's a derv so your oil light will come on under 0.25 bar [3.68 psi]
which at £3 I would replace

[HarryMann]

Do not rev a TD from startup...

Idle should be about 900 rpm, sometimes is a bit more

Wait for the gloplug amber light to extinguish, then start, foot off the right pedal

Listen and watch... only when the dry rattly noise stops and the oil light extinguishes or any gauge starts to climb , aplly light pressure and to circulate oil in cold weather, then holding at approx 1500~2500 rpm for a minute or so is OK.

.3 psi a bit low, maybe 0.3 bar (~ 4.5 psi)

The engine will not be harming itself at no-load idle*, for 5~10 seconds (mine is a newish lump and takes several secods for the noise to go and the gauge to start rising, don't worry)... I've also got a large oil cooler circuit containing about 2.5 litres of oil

* everything will be taken care of by boundary lubrication, just use a good semi-synth 15~40W oil and keep it clean and well filtered

[malmoy]

Thanks for the replies.

I had a feeling there may be more than one opinion. I will get the idle sorted.

Mal.

[dave friday]

Mine takes 5seconds[warning light out oil pressure 3bar air temp23c oil level just under half way between the two marks].interestingly as the oil level goes down the time taken for the oil light goes up!!.
This was the first start of the day,when i re-start the van the oil light goes out almost immediately.