# Oil level reading



## Biglol (Jul 16, 2007)

I drive a Peugeot boxer on a 53 plate and I broke down in France in 2015. After a diagnostic check the garage in france told me the oil level was too high. The oil level reading said "High".
They informed me that it was dangerous to have to much oil as it could damage the CAT.
This week I have just had a full service and the oil reading is again showing "High". The garage informed me they put in the manufacturers recommended amount.
I believe it says in the manual that the oil level reading should show 3/4 dots and not "High"


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## cabby (May 14, 2005)

Typical so called mechanics, told what the amount is so pour the whole amount in, never bothering to stop before the end and try the dipstick. Or have they done away with that now to save a few bob.

cabby

Oh yes since when did those sort of level readers get accurate, so even more reason to do a manual check surely.


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## gaspode (May 9, 2005)

Biglol said:


> They informed me that it was dangerous to have to much oil as it could damage the CAT.


Quite true, it could also get past the engine rear oil seals and damage the clutch.


Biglol said:


> This week I have just had a full service and the oil reading is again showing "High". The garage informed me they put in the manufacturers recommended amount.
> I believe it says in the manual that the oil level reading should show 3/4 dots and not "High"


I'd change my garage then.

The garage should check the oil level using the dipstick after they've done an oil change, not just rely on the refilling data.
Strangely enough, I've found the opposite problem on all the Fiat diesel engines I've ever serviced, they always show low if you only fill with the recommended amount, when checking the dipstick after half an hour I usually find they need more oil. The level reading should indeed be 4 dots when completely full and standing on level ground - but don't rely on it, it's only for guidance. For an accurate reading let the engine stand for half an hour after stopping and use the dipstick.


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## TheNomad (Aug 12, 2013)

NEVER EVER overfill your engine oil. It can do massive damage to your engine.


The 'MAX' mark on the dipstick is exactly that: the absolute MAXIMUM level.
DO NOT aim to fill to that level; always aim to fill to a little below that maximum level.

Always double check on the dipstick what level the apprentice idiot at any garage you use has filled your pride and joy up to before you leave - if it's at all above the maximum level then insist they use their suction pipe extractor to remove the dangerous overfill excess. And then fire them.


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## Devonboy (Nov 19, 2009)

My last Peugeot Boxer based MH also suffered this same issue. When serviced the garage were at a loss to understand as they had checked the dipstick in the workshop which was perfectly level. The gauge still read high.


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## eurajohn (May 9, 2005)

Agree with using the dipstick.


If the rear main seal on an engine leaks it will cause oil to drip out of the bottom of the bell housing it won't go onto the clutch, the clutch is on the opposite side of the flywheel to the oil seal and centrifugal force will spin it off into the housing, I guess if the leak was allowed to continue for long enough then maybe enough could drip onto the clutch assembly when engine was stationary to cause problems. Oil on the clutch centre plate almost always comes from a gearbox first motion shaft oil seal leak.


The biggest danger from overfill is the likelihood of "runaway" which is caused when the excess oil is carried over through the re-circulating system into the turbo which then feeds the combustion chamber with an excess of oil allowing the revs to rise until the engine self destructs.
There is also the possibility of damage to the cat for the same reason as above.
.


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## gaspode (May 9, 2005)

eurajohn said:


> If the rear main seal on an engine leaks it will cause oil to drip out of the bottom of the bell housing it won't go onto the clutch, the clutch is on the opposite side of the flywheel to the oil seal and centrifugal force will spin it off into the housing, I guess if the leak was allowed to continue for long enough then maybe enough could drip onto the clutch assembly when engine was stationary to cause problems. Oil on the clutch centre plate almost always comes from a gearbox first motion shaft oil seal leak.


That's very true - in theory.

But what happens is that the back of the flywheel has the oil from the leaking seal run down it (on the side opposite to the clutch). Then the engine is started and the oil is flung off by centrifugal force onto the inner face of the bellhousing. From there it proceeds to drip onto virtually everything inside the bellhousing (including the clutch).
I don't know how it might affect modern dual mass flywheels (I never had to work on diesels) but I imagine it's likely to do some harm there as well.
Not a good idea to overfill sumps whichever way you look at it.


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## bob-in-dav (Aug 11, 2013)

Don't be too quick to criticise the garage as your oil level can rise for a number of reasons.

If you had a dpf, which I don't think applies in your case, diesel can be dumped into the sump if unburnt in the dpf.

Leaking injectors on some engines can also lead to rising sump level.


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