Too much oil - diesel

Clareman · 17-02-2021 3:59pm #1

A friend of mine just rang me, he's delighted to be sat in an empty office while he's getting something to done with his BMW at a maindealers, he mentioned that the dealers told him that his car has excessive oil because of too many short journeys he had been making recently, the car was serviced about 1,000km ago and they are saying that it'll be 280 to drain the oil, reprogram the car to allow for shorter journeys and refill the oil, that sounds like pulling the piss to me but I said I'd ask.

How would a car add oil to itself just because of about 1,000km of short journeys and what would be the minimum journey for a diesel? Oh yeah, would there be any harm in not draining the excess oil?

cruizer101 · 17-02-2021 4:03pm

I can't see how short journeys would lead to excessive oil.
Excessive water in the oil maybe as you can get condensation in the engine which isn't driven off by the engine getting hot enough, although I thought the solution to that was take it for a good run.
Maybe would be worth changing the oil and trying to take for some more decent runs.
But an oil change should be a lot less that 280

Clareman · 17-02-2021 4:07pm

I can't figure out how more oil could be added when there's no oil being added, it has to be from another source and can't be oil so it's either diesel or water which can't be good.

colm_mcm · 17-02-2021 4:16pm

It’ll be diesel mixing with the oil.

The reprogramming the car bit sounds suspect.

colm_mcm · 17-02-2021 4:20pm

Some general info here

https://www.azom.com/article.aspx?ArticleID=16891

Clareman · 17-02-2021 4:30pm

Every day is a school day, I can't say I know much about cars but I never knew that diesel can going into the oil, I always thought they were completely separate systems.

bazz26 · 17-02-2021 4:36pm

Diesel is mixing with the oil in the sump causing the oil level to go above max rather than having excessive oil. It could be DPF related and the short journeys could well be the contributor if the DPF is not completing it's regen.

tcawley29 · 17-02-2021 4:41pm

colm_mcm wrote: »

It’ll be diesel mixing with the oil.

The reprogramming the car bit sounds suspect.

Just a guess on my part but maybe there was a miscommunication and by reprogramming they mean a forced regen

Clareman · 17-02-2021 4:41pm

Probably more suitable for a different thread but what would be the minium journey or number of short journeys or whatever for a diesel? I think his car is a 2 litre 5 series.

Clareman · 17-02-2021 4:42pm

tcawley29 wrote: »

Just a guess on my part but maybe there was a miscommunication and by reprogramming they mean a forced regen

Possibly could be, this is third hand information and 2 of the people involved know nothing about cars, hence they drive BMWs

ongarite · 17-02-2021 4:46pm

Has your friend checked the oil level with dipstick themselves?
Issue could be as simple as faulty oil level sensor, pretty common issue.

Clareman · 17-02-2021 4:50pm

ongarite wrote: »

Has your friend checked the oil level with dipstick themselves?
Issue could be as simple as faulty oil level sensor, pretty common issue.

I can say with almost 100% certainity that he has not, I would almost be as confident that he has never opened the bonnet of the car

MAJJ · 17-02-2021 4:57pm

I was assuming this was a mazda with a major flaw. Something has to be very wrong here.

punisher5112 · 17-02-2021 5:19pm

If the car isn't getting up to the correct operating temperature and a regen is required then this most definitely won't be good for the car.

The diesel mixes with the oil and the car tends to go at a slightly higher revs when trying to regen.

Can he bring it out for some longer spins on a motorway even if it's going in circles as such.....one exit and back etc.

sumo12 · 17-02-2021 5:23pm

Failed DPF regens most likely, diesel seeping down past rings into the oil if it is a system that uses post-injection to heat the DPF up. Once the oil level is high and the light is in, the ECU will prevent any further regen attempts until level is corrected

maestroamado · 17-02-2021 5:27pm

I am guessing the oil was over filled when serviced.
There is a gaget that will pull the oil out through the dip-stick.
I suggest that your friend borrows/buys one of these and remove a litre or so.
Then top up with same oil to exact mark on stick and monitor for a few weeks.
Personally i have the engine warm when topping as oil filters down better.

bazz26 · 17-02-2021 5:31pm

I think it was stated that diesel has mixed with the oil in the sump that has raised the level rather than an overfill.

maestroamado · 17-02-2021 5:38pm

bazz26 wrote: »

I think it was stated that diesel has mixed with the oil in the sump that has raised the level rather than an overfill.

The very fact that it is being serviced in a mail dealer suggests to me that its unlikely as this cannot be old car.
I have seen what you say happen but never on a car that someone was getting serviced at main BMW dealer.
I think if the diesel getting to sump on newer car it cost considerably more than €280 to sort...

BorneTobyWilde · 17-02-2021 5:54pm

Diesel mixing with oil to the point it's filling the dipstick beyond max is not good. Should never happen, not to the point it's noticeable.
Engine oil goes black for a reason, there is of course contamination with the combustion process and trace elements of fuel, but to this extent, that's not cool.
They never said it was that though, it's just a theory of a poster.

colm_mcm · 17-02-2021 6:06pm

BorneTobyWilde wrote: »

Diesel mixing with oil to the point it's filling the dipstick beyond max is not good. Should never happen, not to the point it's noticeable.
Engine oil goes black for a reason, there is of course contamination with the combustion process and trace elements of fuel, but to this extent, that's not cool.
They never said it was that though, it's just a theory of a poster.

It does happen though.

kermitpwee · 17-02-2021 6:08pm

BorneTobyWilde wrote: »

Diesel mixing with oil to the point it's filling the dipstick beyond max is not good. Should never happen, not to the point it's noticeable.
Engine oil goes black for a reason, there is of course contamination with the combustion process and trace elements of fuel, but to this extent, that's not cool.
They never said it was that though, it's just a theory of a poster.

It's diesel, there is no other option. They don't overfill in main dealers, the oil put in is precise not a guess and top up job

Widdensushi · 17-02-2021 6:13pm

colm_mcm wrote: »

It does happen though.

It does happen, probably happening alot more with the lockdown, I think it is what happened to me, high oil light went 1000km before service was due last time,so serviced a bit early, the fact that the car in the op has only done 1000km since service might indicate that it was overfilled, or else they have a bigger problem.

maestroamado · 17-02-2021 6:15pm

bazz26 wrote: »

I think it was stated that diesel has mixed with the oil in the sump that has raised the level rather than an overfill.

Yes it was stated but the OP said the BMW main dealer just said excessive oil, i am sure the dealer would know in an instant if oil/diesel mixed.
I also expect there be loads of flashing lights as i am thinlking this not old car.

Could it be the plugs/points???

Truckermal · 17-02-2021 6:22pm

maestroamado wrote: »

Yes it was stated but the OP said the BMW main dealer just said excessive oil, i am sure the dealer would know in an instant if oil/diesel mixed.
I also expect there be loads of flashing lights as i am thinlking this not old car.

Could it be the plugs/points???

Plugs and point's on a 520D?

bazz26 · 17-02-2021 6:25pm

It's definitely in trouble if it has them.

kermitpwee · 17-02-2021 6:29pm

Truckermal wrote: »

Plugs and point's on a 520D?

This place is gone to the dogs, I don't know why people comment when they haven't a clue. I know nothing about farming so I stay away from that forum.
1000km is easily enough if all short journeys to cause the diesel to mix with the oil.
I see it regularly on my buddies 2018 focus diesel. He has had to get it serviced twice after less than 2000km since the last service.
Actually if its not the plugs and points would it be the Carburettor?!!!!!!!!

mickdw · 17-02-2021 6:32pm

I dont know it id agree about main dealers refilling to exact level. In my experience, they over fill to a safe level 9 times out of 10 possibly to help with the stupidly long intervals

maestroamado · 17-02-2021 6:36pm

bazz26 wrote: »

It's definitely in trouble if it has them.

I used say that to the young guys when picking the diesel to give them a laugh as they thought i not knoo...

route66 · 17-02-2021 6:42pm

This exact issue happened on a friends 2017 (current shape) BMW 520D.

Most people don't realise the downsides of running a diesel - no matter how new or premium; in fact new diesels are much more fragile than old ones. Short runs causes them lots of problems.

If short runs are what he uses the car for, then he should replace it with an Electric Vehicle or something Petrol or Hybrid powered

shanec1928 · 17-02-2021 6:45pm

ongarite wrote: »

Has your friend checked the oil level with dipstick themselves?
Issue could be as simple as faulty oil level sensor, pretty common issue.

Possibly no dipstick. Had a g30 520d on loan that was checked through idrive

colm_mcm · 17-02-2021 6:47pm

route66 wrote: »

This exact issue happened on a friends 2017 (current shape) BMW 520D.

Most people don't realise the downsides of running a diesel - no matter how new or premium; in fact new diesels are much more fragile than old ones. Short runs causes them lots of problems.

If short runs are what he uses the car for, then he should replace it with an Electric Vehicle or something Petrol or Hybrid powered

A lot of people who would usually be doing big mileage are now finding themselves working from home. You couldn’t have foreseen that.

Too much oil - diesel

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