overfilling with oil?

[Sergeant Pluck]

following on from a few threads recently about oil consumption - i was wondering exactly what happens if you overfill an oilhead? the booklet says that you've damaged the engine. what have you damaged and how would you know?

i once overfilled my r100 by quite a bit and did maybe a 1000 or so miles before i realised. that was about 10,000 miles ago and i've noticed no damage or change whatsoever - but then i reckon that old thing would run on treacle...

so what about an r1150?

pr0ne

 

[adamski49]

I'm no expert by any means, especially on the mechanical side of things, but the increased level does mean that oil can get pumped / blown (?) into the airbox via the crankcase breather. You could always remove little drain plugs to see if that's happened.

Apart from that something to do with increased oil pressure and blowing seals.

Having overfilled earlier in the year a tip I was given by a courier was to remove the sump plug with the engine cold to drain a small amount of oil into a pan and quickly reinsert plug and tighten. Refill as necessary.

HTH

Adam

 

[the celt]

Hi Prone,
If you overfil with oil it can lead to the clutch plate being covered in oil, you will then have to fit a new oil ring seal from engine to gearbox plus new clutch, and this is a right pain in the arse.
I have done it, I now only fill up to the red dot on the inspection window and keep a weekly check on it.
regards
jose

 

[boxer]

Having overfilled earlier in the year a tip I was given by a courier was to remove the sump plug with the engine cold to drain a small amount of oil into a pan and quickly reinsert plug and tighten. Refill as necessary.

Even easier and cleaner is to remove and empty the oil filter.

Russ.

 

[jimbo]

Admittedly when I looked into this it was from a car perspective, but if the oil is too full the crank will start hitting the oil. I'm told you can actually hear this and it will cause oil aeration.
I would imagine that with a flat twin eventually it would be so high the oil would start to run into the cylinders to meet the piston travelling down at speed!
Its not clear to me that these thigs would directly dammage anything, but it all sounds rather messy.
Jimbo

 

[adamski49]

Even easier and cleaner is to remove and empty the oil filter.

Russ

Have you done this and does it work?

I only remove my filter after most of the oil has drained and it seems to let a lot of oil out even then. I'd have imagined that it would be similar to removal of the drain plug (albeit higher up the oil level) and trickier to get a clean mating face on the filter for re-installation.

I take it this is not the case.

Adam

 

[boxer]

Adam.

Sure works on my 1100. Worked last week when I changed just the oil filter. Other than what's in the filter I only lose a little oil and cleaning the mating face is just the same as when all the oil has been drained.

Russ.

 

[andy white]

pr0ne,

I am not an expert of the boxer engine, but genrally if you excessivly overfill a sump with oil you could Hydraulicly lock the engine, which is very bad , It is best just to top the engine up when needed, if your engine is using a lot of oil you are best to get it checked out.

 

[Mike Saunders]

With respect to overfilling, I've a sneaky suspicion that dealers tend to overfill at the services, the oil window appears to be full when checked for quite a while, ie a considerable mileage, before the oil level 'drops' into view, then its back to the sort of level fluctuations and indicated consumption that promted my initial 'rant' on the subject.

So, if the dealers overfill, ( in moderation one would presume )
can it be that bad.

Mike

 

[adamski49]

Mike

I think dealers overfill on the service because (probably for speed) they use the quants shown in the manuals rather than by checking the sight glass.

I've never yet done an oil change and managed to get the amount quoted into the engine before getting to the top of the sight glass.

Within a 1000 miles though it's normally back into view.

I bet if you mentioned it to a dealer it wouldn't be a problem if they had done the oil change whereas if you had done it your warranty would be void...

Adam

 

[Wreford Miles]

Knew I guy (Gary Palmer... you still out there mate) who accounts a blown seal to the gearbox due to overfilling with oil.

Tip I was given by Sawbridgeworth BMW when I filled my bike past the sight glass was to lean the bike away from me when looking at the sight glass.

By doing this you can tell if your only just over in which case they said dont worry.

Thier tip to remove oil was to use an old gearbox oil type container with a plastic tube to suck some straight out through the oill fill hole.

 

[notadrop]

Thier tip to remove oil was to use an old gearbox oil type container with a plastic tube to suck some straight out through the oill fill hole.

Can't see it working with the boxer? If you remove the valve covers there is only a cc or 2 of oil in the bottom of the cover?

 

[Wreford Miles]

OK just lay the bike on the verge and let a little drain out...

 

[AdamZ]

A short while ago I was topping up my oil in a service station and the bike was almost knocked over by some idiot in a car determined to get to the pump ahead of me...

Despite my mild mannered, diplomatic approach to life I felt compelled to pass some casual and innocuous comments on his parentage and intelligence.

This mild aberration distracted me from my task and I significantly overfilled with oil resulting in blue smoke where turning the wick up at low engine speeds (I think this was something to do with the pressure differential between the exhaust extraction and the seal provided by the piston rings....

Fearing the worst and potentially a cracked ring I eventually got home after around 60-70 miles, sump guard off and drained about 200cc of oil out...

Since then no problems but it had me worried

 

[The Mechanic]

Exces oil

Too much oil in the sump will cause (depending on how much you have overfilled by) the crank to hit the oil, apart from (already mentioned) aeration of the oil it will also vibration through the crank. Too much oil will also possibly create (when the oil is hot) too much crankcase pressure (fumes etc trying to vent through the breather) which acts directly upon the rear main crankshaft oil seal and thence the problems also already mentioned (clutch contamination/slip).

The chances of creating a situation where 'hydraulic lock' may occur (you can compress a gas but you cannot compress a liquid) are greatly increased, this would need the bike to be running whilst laid over (on its side for example) and for the oil to find its way up passed the piston oil control rings onto the compression side of the piston (crown). It is entirely possible to drown the oil control rings if too much oil is about, hence the blue smoke (already mentioned).

The main problem that causes overfillng is us men, as we pour- just like when you have sex - you tend to rush the last little bit! :monasmile