Fred Jones wrote:
Without knowing make etc it is hard to say

Thanks here are the model details:

Mazda 6 , 2.3 06 plate


Google is you friend

http://www.automotiveforums.com/t698663.html

Mazda 6's drink oil.

PCV
The PCV (Positive Crankcase Ventilation) Valve is a check valve that
allows excess exhaust fumes in the crank case to re-enter the intake
manifold and be re-combusted for emissions sake.


Problem:
If the valve breaks (its basically plastic), one of two things can happen,
http://forum.mazda6tech.com/viewtopic.php?p=36503#36503

1: The valve gets stuck close. Pressure builds up in the crankcase,
eventually finding an outlet. This usually results in oil spraying back
up into the intake tract, or blowing the dipstick out of its holder.

2: The valve gets stuck open. When vaccuum is applied (application of
throttle), the intake air sucks the oil out of the crankcase using the
pcv hose as a large straw.

In article db7211f6-e442-4917-b5a7-
, Fred Jones says...

Without knowing make etc it is hard to say

Thanks here are the model details:

Mazda 6 , 2.3 06 plate

My 118,000 04 plate Mondeo uses none. My 23 year old Capri with 80k on
uses none. 1 litre between services would be reasonable.

--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams

On Thu, 07 May 2009 19:35:36 +0100, Blah wrote:

Problem:
If the valve breaks (its basically plastic), one of two things can
happen, http://forum.mazda6tech.com/viewtopic.php?p=36503#36503

1: The valve gets stuck close. Pressure builds up in the crankcase,
eventually finding an outlet. This usually results in oil spraying back
up into the intake tract, or blowing the dipstick out of its holder.

Seems like that would be noticeable?

2: The valve gets stuck open. When vaccuum is applied (application of
throttle), the intake air sucks the oil out of the crankcase using the
pcv hose as a large straw.

That sounds like a litre per mile, not 1700 miles.

Seriously though, a lot of modern engines (I've heard) get through oil
like there's no tomorrow.

I had a Supra once that drank a litre every 300 miles or so, but I could
see where that was going in the blue clouds behind me...

wrote:
Thus spake johannes ) unto the assembled multitudes:
Without knowing make etc it is hard to say. My puggy 206 hasn't drunk a
drop of oil in 20000 miles.

Same here for my Saab 9000 in 161000 miles.

So you're saying you have never changed the oil (or had it changed) in your
Saab in 161,000 miles?


No we are saying that the cars haven't DRUNK any oil which is a totally
different thing.

On 2009-05-08, Alan wrote:
wrote:
Thus spake johannes ) unto the assembled multitudes:
Without knowing make etc it is hard to say. My puggy 206 hasn't drunk a
drop of oil in 20000 miles.

Same here for my Saab 9000 in 161000 miles.

So you're saying you have never changed the oil (or had it changed) in your
Saab in 161,000 miles?


No we are saying that the cars haven't DRUNK any oil which is a totally
different thing.

How would you know that if it has been refilled every 10k(?) miles?

--
David Taylor

On Fri, 08 May 2009 07:52:09 +0000, David Taylor wrote:

[...]

No we are saying that the cars haven't DRUNK any oil which is a totally
different thing.

How would you know that if it has been refilled every 10k(?) miles?

Presumably because the level has stayed the same on the dipstick during
that time?

Chris

--
Remove prejudice to reply.

David Taylor wrote:
On 2009-05-08, Alan wrote:
wrote:
Thus spake johannes ) unto the assembled multitudes:
Without knowing make etc it is hard to say. My puggy 206 hasn't drunk a
drop of oil in 20000 miles.
Same here for my Saab 9000 in 161000 miles.
So you're saying you have never changed the oil (or had it changed) in your
Saab in 161,000 miles?

No we are saying that the cars haven't DRUNK any oil which is a totally
different thing.

How would you know that if it has been refilled every 10k(?) miles?


Derrrrrrrrrrr. The oil level hasn't gone down at all between changes.

On 2009-05-08, Alan wrote:
David Taylor wrote:
On 2009-05-08, Alan wrote:
wrote:
Thus spake johannes ) unto the assembled multitudes:
Without knowing make etc it is hard to say. My puggy 206 hasn't drunk a
drop of oil in 20000 miles.
Same here for my Saab 9000 in 161000 miles.
So you're saying you have never changed the oil (or had it changed) in your
Saab in 161,000 miles?

No we are saying that the cars haven't DRUNK any oil which is a totally
different thing.

How would you know that if it has been refilled every 10k(?) miles?


Derrrrrrrrrrr. The oil level hasn't gone down at all between changes.

How do you measure a drop of oil with a dipstick?

--
David Taylor

Chris Whelan gurgled happily, sounding
much like they were saying:

No we are saying that the cars haven't DRUNK any oil which is a
totally different thing.

How would you know that if it has been refilled every 10k(?) miles?

Presumably because the level has stayed the same on the dipstick during
that time?

Right. So it hasn't lost a crudely-measurable amount of oil in 10k. Which
is very different from it not having lost any in 160k+.

On Fri, 08 May 2009 08:27:19 +0000, Adrian wrote:

Chris Whelan gurgled happily, sounding
much like they were saying:

No we are saying that the cars haven't DRUNK any oil which is a
totally different thing.

How would you know that if it has been refilled every 10k(?) miles?

Presumably because the level has stayed the same on the dipstick during
that time?

Right. So it hasn't lost a crudely-measurable amount of oil in 10k.
Which is very different from it not having lost any in 160k+.

It certainly won't have lost a litre every 1,700 miles like the OP's will
it?

The difference between the full and refill marks on average is usually
around a litre, and is perhaps 20mm on the dipstick. Even with my old
eyes, I can visually estimate if the level is on the line, or 1mm below
it. This would give the ability to detect a loss of 50ml.

Now if you accept that "a drop" is not a scientifically accepted measure,
then 50ml in a fill of perhaps 5 litres is certainly insignificant.

In the context of the OP's question, it's surely acceptable saying a car
is using no oil between changes if the level remains within the
manufacturer's specification.

Chris

--
Remove prejudice to reply.