Cold Winter Mornings - Page 8

Gate Keeper · 5th February 2012, 08:49

I have heard it is worse for there to be too much oil in than not enough.
A few days ago I was away and perchance did a dip-stick check before setting off. Empty. Topped up with a litre and still empty. Went to Kwik-fit and they also found the tank was empty. Car was ramped up, engine check done, no leaks other than underbody condensation was found. No oil warning light came on. Oil was replaced and seemed OK again.

A mystery as to how the car ran on empty without it showing any signs and no warning lights. Now it has too much oil in it, as it is over the marker.

Maybe it was the cold winter morning.

lovema75 · 5th February 2012, 13:34

Quote:

Originally Posted by SD1too

I'd like to help you out with your car's description. It's spelt connoisseur.

I thought computers were supposed to help us with things like this.

Simon.

I be ever so grateful 'guv.

Wot with ma paper round after skool, up the chmneys at the weakend and doon the mines during holidays ah niver did get the chance to get brung up propa.

I am off to chase a haggis - anyone seen ma kilt?

COLVERT · 5th February 2012, 14:35

Quote:

Originally Posted by lovema75

I be ever so grateful 'guv.

Wot with ma paper round after skool, up the chmneys at the weakend and doon the mines during holidays ah niver did get the chance to get brung up propa.

I am off to chase a haggis - anyone seen ma kilt?

If yer can't find yer kilt to go 'aggis 'untin will this do instead ready done ???

COLVERT · 5th February 2012, 14:45

Quote:

Originally Posted by Unclefista

The extra fuel injected for "cold start enrichment" (choke) washes the lubricating oil from the bore walls, so called "bore wash" which allows the pistons (rings) to run against the bore walls and causing accelerated wear.
This happens especially when cold and idling, due to the engine not heating up very quickly at idle, cars are designed to be as economical as possible, especially when not under load.
They warm up much more quickly when they're under load and using much more fuel.

Doesn't the extra petrol sort of DILUTE the oil rather than washing it off ???

It's gotta be still there somewhere hasn't it ??? Just a bit thin but still stopping metal to metal contact !!!

What hasn't been mentioned in this thread is the damage caused by corrosive substances generated in a cold engine. Isn't it this that causes wear and damage much more than the effects of running for a short while with slightly diluted oil ???

Food for thought.

( After 74 posts. Lol. )

lovema75 · 5th February 2012, 17:12

Quote:

Originally Posted by COLVERT

If yer can't find yer kilt to go 'aggis 'untin will this do instead ready done ???

Aye, that'l dae fine lad!

lovema75 · 5th February 2012, 19:38

Quote:

Originally Posted by COLVERT

Doesn't the extra petrol sort of DILUTE the oil rather than washing it off ???

It's gotta be still there somewhere hasn't it ??? Just a bit thin but still stopping metal to metal contact !!!

What hasn't been mentioned in this thread is the damage caused by corrosive substances generated in a cold engine. Isn't it this that causes wear and damage much more than the effects of running for a short while with slightly diluted oil ???

Food for thought.

( After 74 posts. Lol. )

This thread will never die! Yes your right, the oil does also become more diluted with neat fuel and more acidic - another reason to change more frequently.

But its also worth keeping in mind that this problem was much worse with old carburator engines, where retired Miss Pettygrew drove 2 miles to the post office and back to collect her pension - choke out out all the way, engine screaming at a 2500 rpm idle, belching black sooty smuts and utterly destroyed after a few years.

David340R · 5th February 2012, 22:04

Quote:

Originally Posted by thebiglad

2. Oils and lubrication - oil and it's ability to protect engines, is expressed in terms of it's viscosity at 0°c and 100°c such as 10w-40; 5w-40 etc. The first figure expresses viscosity at 0°c and the 2nd at 100°

So even though when we look at cold oil it appears thicker and warm oils appear thinner, a multigrade oil is designed to operate "thinly " at low temps to give effective lubrication/protection to a cold engine and "thicken" to compensate for rising engine temps.

Look at some of the latest engines that use 0w-40 & 0w-50 engine oil, it's like water at ambient temp but thickens as the engine temp rises.

Sorry, but this is wrong. A 10w-40 has the viscocity of a traditional 10 weight mono-grade oil at low temperature and of a 40 weight oil at high temperature. This doesn't mean a multi-grade gets thicker at high temperature, it means is doesn't get as much thinner.

COLVERT · 7th February 2012, 19:08

Quote:

Originally Posted by David340R

Sorry, but this is wrong. A 10w-40 has the viscocity of a traditional 10 weight mono-grade oil at low temperature and of a 40 weight oil at high temperature. This doesn't mean a multi-grade gets thicker at high temperature, it means is doesn't get as much thinner.

I think I might just have to do that test I mentioned in post 65, just to see.

Colvert.

5th February 2012, 08:49	#71
Gate Keeper This is my second home 4X4 Join Date: Jul 2010 Location: Nairobi Posts: 20,160 Thanks: 8,286 Thanked 7,017 Times in 4,160 Posts	I have heard it is worse for there to be too much oil in than not enough. A few days ago I was away and perchance did a dip-stick check before setting off. Empty. Topped up with a litre and still empty. Went to Kwik-fit and they also found the tank was empty. Car was ramped up, engine check done, no leaks other than underbody condensation was found. No oil warning light came on. Oil was replaced and seemed OK again. A mystery as to how the car ran on empty without it showing any signs and no warning lights. Now it has too much oil in it, as it is over the marker. Maybe it was the cold winter morning.