Engine oil over filled

[FNqGu04]

I know this has probably been posted before .
What will over filling the engine oil cause ??

tia Craig

[mudnut]

It takes a fair bit for a lot of engines as a their manufacturers allow for the layperson factor. If there is enough, you get components smashing into the oil.

The ZD30 being overfilled can lead to failure as over time the oil mixes with soot from the EGR and cakes it on the inner surface of the inlet manifold.

[AB]

How much did you overfill it by?

[threedogs]

ZD30 doesnt need like being overfilled one bit ,drain a bit out
a little under is ideal

[Rumcajs]

The counter question is why are you asking?

Most DIY persons will happily overfill especially in ZD30 scenario because the oil drain times and because Nissan had stuffed up the whole thing.

So if you let it drain for an hour or so and only fill back 7.0-7.5 litres instead of Nissan's 8.2 L advice you will find that dipstick max mark will match perfectly after you run the engine and then check next morning before starting it. If you fill 8.2 L and check after 15 mins of running it will show on max mark but way above it if you check next morning. Imagine if you do this regularly and all you are doing is ever increasing the amount of oil in the sump. So question is, should you be filling up based on the dipstick mark or by Nissan recommended volume?

I check oil level first thing in the morning before the trip after the engine has been off overnight.

Another thing to watch for is the scenario where it seems oil level is increasing over the time (some refer to as "engine is making oil", it is usually diesel fuel leaking through spill line assembly because that is not visible outside of the motor you will be oblivious to it until either you check the oil level or something goes bang because diesel will dilute oil and is not a great lubricant.

To answer the original question, too much oil in the sump/crankcase causes additional breathing of oil droplets out of the breather (aka increasing crankcase pressure) which will then be spread in to your intake and coating the internals of it with carbon sludge causing all sorts of problems. If you have open crancase ventilation then you'll be just wasting your money and poluting enviroment as that excess oil will be forced out of the breather pipe.

Regards