Oil overfill

Had a little mishap with my old banger (1988 Colt) the other day. Before setting off for a 120 mile journey I thought I'd check the oil. It was a bit low, so I topped it up to about halfway between min and max readings. I then set off.

About 5 miles into the journey it occurred to me that I didn't remember putting the oil filler cap back on. Stopped and checked, and indeed the cap wasn't on and oil had splashed out of the filler cap onto the air intake and other casings. Very luckily the cap had been trapped under the bonnet so I still had that. I replaced it and added some more oil because I didn't know how much I'd lost, and then finished the journey uneventfully.

Now I've managed to check the oil when cold and it seems it's substantially overfull. It's about half the distance from min to max above the max marker. So what to do?

To complicate matters, the car has a very slight head gasket leak so when parked it loses a drop of oil per night. It takes about 6 months to go from max to min at about 30 miles/week.

Is having this much oil going to cause damage, particularly to the head gasket seal? Is it better to drain it? I've got the 120 mile return journey on Monday so don't want to push it too much again. If draining it is advisable, is it something that can be done without putting the car on axle stands (I'm a bit of a novice at cars, as you might notice, though I've done a lot of maintenance of pushbikes)? Or better to take it somewhere to do it?

Thanks Theo

Reply to
Theo Markettos
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It ain't the headgasket you need to worry about but the bottom end.

Easiest way to drop the oil level is to whip the oil filter off, empty the oil out of the oil filter and put it back on the engine. The filter will contain the thick end of 1/2 litre of oil which should be enough to take it as close to the maximum as matters.

Reply to
Conor

very few cars are actually harmed by a bit too much oil. just drive it.

mrcheerful

Reply to
mrcheerful

Get the car fixed! My local Masterfit regularly overfills cars with oil. They do it each time I take mine in for the service. They must get the oil in 5litre containers and mine takes less, so they just tip the lot in. I know to check it before leaving now. It's usually about 1cm over the maximum marker. I also check they have done all the work they claim in full view of their car park cameras! Unless you thrashed the car a small overfill for a short time will not harm it. If it's leaking anyway then you will not have the same type of pressure building up. Just undo the nut at the bottom of the sump and drain a bit of oil off. Mind it doesn't go straight down your sleeve! Unless your engine is upside down I don't see how oil would be dripping from near the head gasket at night. It sounds more like a small oil seal causing that. I had the same problem years ago on a sierra. If you leave it, it will get worse and affect other parts such as the clutch.

Reply to
simon

So you've done 115 miles on this minor overfill, and no problem?

No problem. Ignore it.

Steve

Reply to
shazzbat

And watch water come out. High oil other than overfilling is also a symptom of water getting into the sump via various sources.

PDH

Reply to
Paul Hubbard

180 now. Mostly 10ish mile pootling to the next village, but 120 miles of A-road thrash (0-70 asap out of the layby onto the dual carriageway, go up through the gears after every little village). It maybe feels a bit more sluggish but it's hard to tell - there are hills around here which makes driving rather different to Cambs.

Is it the sort of thing that's likely to go boom within the first few miles if it's wrong, so if it doesn't it'll be OK, or does it gradually wear away at the seals? Will an overfill be burnt off quicker? The leak (which is out of the side of the engine near the sparkplugs which I was told was the head gasket, don't have a diagram here to see where it's coming from) presumably occurs when it's running and just collects on the metalwork before slowly dripping out - I'd guess the pressure will cause this to leak more. Is that a bad thing?

The advice in general here seems to be to leave it alone, which sounds fair enough to me. I might have a look at draining it, but that'll be after the return 120 miles. I tend to be cautious about these things not knowing exactly what the failure modes are.

Thanks for the comments - I'm learning by my mistakes at the moment :)

Theo

Reply to
Theo Markettos

I think I read a post a while ago that said if the oil level was too high, the bottom end of the engine can whip it into a foam - foam doesn't pump like oil, and can result in a seized engine.

Could be wrong though :-}

Reply to
Colin Wilson

That's one of those, both points are true but A does not imply B will happen. Youdon't turn all the oil into foam, but the drag really affects your fuel economy. More to the point the oil ends up in the PCV system & gets burnt, potentially in suffecient quantitie to bugger your cat. Unless you fill it to the brim & hydraulic lock it, but that would take real effort.

Reply to
Duncan Wood

It's probably worth avoiding high revs until the level has dropped a bit, because this is the condition where oil aeration (and subsequent damage) is most likely.

Reply to
www.fuelsaving.info

Its ready for the scrappers..weigh it in.

Reply to
Porkch Ease

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