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Can you use your X5 without the ccv oil separator for a short period?
Posted: Sat Jan 10, 2015 11:19 am
by LooneyLeon
As a follow on from my other thread I was wondering if you can use your X5 if you have disconnected / removed the CCV oil sparator value?
I dont mean indefinatley I just mean for a couple of local trips until I can get the parts on tuesday.
Obviously I dont want to do anything thaf would damge the car.
Thanks in advance.
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sat Jan 10, 2015 1:39 pm
by X5-D-Sport
Your choice,
But the oil separator on a diesel engine is a critical part & function, but you will get away with it on a petrol, just may get a stench & smoke.
A diesel engine can do a REV RUN-AWAY with oil droplets in the air induction to the engine.
The engine will literally rev up to destruction with an smallest amount of oil being burned.
You can turn everything off, or whatever.... but it simply will not stop until a piston is hanging out of the block or it seizes up !!!!!
There are aftermarket oil separators on the market for about £30 on Flea Bay, that a lot of the Boy Racer Road Hot Rodders use, and I've got one fitted to my E53 diesel.
The have the advantage that you know how much oil you engine is blowing... and you can put it back in the engine.
If you desperately need to run the vehicle, then block the hose that allows fumes back to the engine intake manifold, thus keeping mixtures correct with a petrol engine, and preventing debris entering the engine - diesel or petrol,
and vent the emission blown-out fumes/oily bits into a pot or jar, so it doesn't make a pond when you park.
With a diesel engine.... DO NOT join the pipes and feed the crank case oily blow outs back into the intake.... or you will likely destroy the engine.
I have seen a diesel engine, that was in good order run to destruction....
In this instance the separator was gummed up and didn't drain, and simply allowed the oily bits back into the intake manifold...
The revs that it achieved were truly scary, and later inspection revealed a broken crank shaft with no 1 piston seized, but the engine kept going even with assorted smashed valves, a blown head gasket, and a huge crack in piston liner 3.
It simply drank all the coolant thru the head gasket blow;
The engine only finally stopped when the sump ran dry and starved the intake of oil.
I'd estimate from the noise that the engine exceeded 12,000 revs.
There was NOTHING worth salvaging, and even the water pump, steering pump & turbo charger were totally destroyed, and even the alternator threw its windings.
so, still want to run the vehicle without a separator ??
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sat Jan 10, 2015 2:05 pm
by sleepyfolk
Sound like it'll probably be ok then
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sat Jan 10, 2015 5:05 pm
by Smeeagain
[quote="X5-D-Sport Salisbury"]
Your choice,
But the oil separator on a diesel engine is a critical part & function, but you will get away with it on a petrol, just may get a stench & smoke.
A diesel engine can do a REV RUN-AWAY with oil droplets in the air induction to the engine.
The engine will literally rev up to destruction with an smallest amount of oil being burned.
You can turn everything off, or whatever.... but it simply will not stop until a piston is hanging out of the block or it seizes up !!!!!
There are aftermarket oil separators on the market for about £30 on Flea Bay, that a lot of the Boy Racer Road Hot Rodders use, and I've got one fitted to my E53 diesel.
The have the advantage that you know how much oil you engine is blowing... and you can put it back in the engine.
If you desperately need to run the vehicle, then block the hose that allows fumes back to the engine intake manifold, thus keeping mixtures correct with a petrol engine, and preventing debris entering the engine - diesel or petrol,
and vent the emission blown-out fumes/oily bits into a pot or jar, so it doesn't make a pond when you park.
With a diesel engine.... DO NOT join the pipes and feed the crank case oily blow outs back into the intake.... or you will likely destroy the engine.
I have seen a diesel engine, that was in good order run to destruction....
In this instance the separator was gummed up and didn't drain, and simply allowed the oily bits back into the intake manifold...
The revs that it achieved were truly scary, and later inspection revealed a broken crank shaft with no 1 piston seized, but the engine kept going even with assorted smashed valves, a blown head gasket, and a huge crack in piston liner 3.
It simply drank all the coolant thru the head gasket blow;
The engine only finally stopped when the sump ran dry and starved the intake of oil.
I'd estimate from the noise that the engine exceeded 12,000 revs.
There was NOTHING worth salvaging, and even the water pump, steering pump & turbo charger were totally destroyed, and even the alternator threw its windings.
so, still want to run the vehicle without a separator ??
[/quote]
Yup you can see a runaway on YouTube .....
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sat Jan 10, 2015 8:28 pm
by X5Sport
It will stop if you block the air intake with a damp towel. No air = no combustion, but you have to be brave enough to open the bonnet, get to the inlet trunk and stick the towel over/into it whilst staring at an engine revving itself to bits.
Not one for the faint of heart......

Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sun Jan 11, 2015 11:23 am
by LooneyLeon
Thanks for the replies guys/girls I think ill just be grown up and leave it until. Tuesday
I can prep it all ready for the new bits so hopefully wont take too long to do once ive picked up the bits.
The only thing stopping me was the fact I snapped the rubber oil return pipe from the bottom of the oil separator that goes into the metal oil return pipe. I have thought about getting a little plastic pipe joint and joining what's left of the broken pipe to the new bit of pipe ive got but figure this would mean that the internal diameter of the pipe where it joins is less and therefore is more likely to get clogged and block up, so have dismissed this idea.
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sun Jan 11, 2015 1:06 pm
by X5Sport
Being a 4.6 at least you won't suffer a runaway. Petrol engines don't suffer that particular nasty as you need a spark to keep it running.
Richard
Re: Can you use your X5 without the ccv oil separator for a short period?
Posted: Sun Jan 11, 2015 2:52 pm
by X5-D-Sport
correct re spark ignition engines.
This forum is a fabulous source of good people and good information.
It is so nice being in contact with decent people & part of this group, eager to help each other save as many pennies as possible.
I'm still learning the many quirks of the X5, and it is amazing how much the BMW main agents don't know about these cars they sell/repair....
Re separator, just collect the spat out oil & you will be OK short term, and also plug the intake manifold pipe from the separator to ensure the fuel mixtures remain correct.
Have a fab weekend.