Oil level problem

[Guyver1]

Since doing the oil change last week, I'm getting different readings every day I check.

It was fine when I put the oil in, following morning it read around 15mm over the max mark, although, my drive is slightly sloping down and to the right.

I parked it on the main road for an hour and it read on the max mark, I've just checked it on the works carpark and it's about 2mm above the max mark.

Could I have an airlock in the oil causing spurious readings ?

I'm taking it to work again on the morning dead early to find the flattest/levelist space to park and will check it after 5 hours when I get my break. If its still just above the max mark do I need to drain some or will that amount be ok?

[Max Headroom]

If it was mine, I would give it a good run and get the engine fully warmed up. Then I would park it on ground that is known to be completely level. The car being level is very important.

Shut down the engine and check the oil level after about 25 mins. This will give enough time for oil to drain from galleries and oilways etc and give you an accurate reading for a warm engine.

I would think it highly unlikely that you have an airlock!

When you check/recheck your oil level, you should do it at approximately the same amount of time after each shutdown. Checking it when hot then checking again when cold my give significantly different readings.

Consistency with time, and level surface is important.

[Alan]

If you get the oil to the right level when you do an oil change it's cold, so that's when I check mine, in the morning when the engines cold.  Am I doing it wrong ?

[Max Headroom]

No, I wouldnt say it's wrong.

The reason I do mine the way I do, is because I want the engine running at full capacity when hot, but I don't want it running overfilled either

[aerojon]

if dipped when stone cold it will show over filled because the some of the oil would have drained back into the sump..

it's when it's at max level on dipstick when stone cold that's when to add oil..

[Guyver1]

I got a dribble over max mark after leaving it 4 hours this morning do I'm happy with that

Filling up on max with a stone cold engine doesn't sound right

[Max Headroom]

Filling up on max with a stone cold engine doesn't sound right

No. That will overfill it and just blow oil out, or worse blow seals out.

Should always be checked warm, but not hot or immediately after shutdown

[ReAxs7]

To pretty much confirm the advice which Trenchfoot has given:

From my 9-3 handbook;

1. Park the car on a level surface.
2. Switch off the engine and wait for 2 - 5 min. [diesel engine: 5 min.].
3. Withdraw the dipstick and wipe it with a clean rag before checking the oil level.

The oil level must not be below the MIN mark on the dipstick, but nor should it be above the MAX mark, since this could result in abnormal oil consumption.

NOTICE: Too high a level can damage the engine.

I was always told that too high a level can lead to increased pressure and burst seals; if anything a little under Max is preferable to a little [or a lot] over.

HTH.

[Guyver1]

it's when it's at max level on dipstick when stone cold that's when to add oil..

I was quoting aerojon

[Max Headroom]

It's likely to be the exact same reason we never to-up aircraft engines when cold - that definately leads to overfilling.
We have a time window in which to check the oil. Again this gives an optimum fill for running when hot.

[aerojon]

on the max when cold,some oil drained back into sump..start car oil pumps back around all the oilways..

oil level will be lower than the max because it's now be recirculated throught out the engine..

i've always(23yrs) had my oil 4-5mm over the max when it's been cold.