alex.stanley

Sorry if this is a repost

I've just read in my new sparkly S2000 owners manual that oil should be checked once the engine has been run and left for a few mins (ie. engine still warm)

In my (relatively short) experience I've always checked the oil when the car has been standing somewhere for a while and so is either nearly or completely cold.

What's the difference really? Which is best?

S2kSi

The way I understand it you should check the oil with the car warm for 2 reasons:

1. When the engine/oil is warm it is less viscous (i.e. runnier)

2. When the car has been standing for a while gravity drags the oil back down to the sump, away from the block.

So you would get quite different oil levels on the dipstick with a recently run, warm engine as opposed to a cold engine that hasn't been running for a while.

So, basically, you'll get a higher reading on the dipstick with a cold engine, which may mean you don't bother topping it up when it actually needs it.

Si

P.S. I'm no mechanic so I've readied myself for a flaming if I've got this wrong!

fluffyninja

You need to get the oil warmed through so it's nice and thin and runs back to the sump properly. If you started it from cold moved a few feet and then stoppped again it would still be pretty viscous and a lot of oil would remain up in the cylinder head and possibly give a dubious reading.

Doesn't really matter whether the oil is warm or cold so long as you check it after it has been warm and has then been left to drain properly

S2KPDQ

I think the most important thing is to check your oil regularly, and consistently i.e. either warm OR cold (don't 'mix'n'match').

This way you can build up a perception of how your engine is/isn't using oil and be certain when you need to top your oil up.

I always check mine first thing on a Saturday morning before starting the car for the first time - no problems so far

Andy

alex.stanley

Thanks guys - I think I'll stick to checking it before I start the car in the morning, it's worked for me thus far, I just wanted to make sure