Oil Consumption

triumphant59

New Member
My 1.4 petrol is using .75l of oil per 1000 miles. It has covered 150k with pretty much full service history. Oil and filter were changed 2000 miles ago using Westway 5w30 synthetic oil. I can’t see a leak, Is this excessive with these miles?
 
I can’t speak for the petrol but the diesel 1.4tdi Engine imho does not seem to use oil.... I’ve had a few over the last 20 years one we have at present has 162k on the clock with no oil use ..our other two lower mile tdis don’t use any oil in between services..(12months) ..either.
But that amount of oil Your using seems very excessive to me ...
 

PlasticMac

Member
Excessive yes. It's either burning it, leaking it, or it wasn't there post service.
Are you saying that after the service, and having travelled 2000 miles, you have put in 2 ltrs of oil in one go, or several small top ups, over 2000 miles?
Mac
 

herx

Member
If you have the owner's manual, have a read and you will see that some oil consumption is to be expected. If I had it next to me I would take a screenshot to share
 
It's excessive and not uncommon to these 1.4 AUA and BBY blocks.

A big culprit is the oil separator part of the pcv system ( positive crankcase system) at the back of the engine. If these become blocked you get the oil consumption you describe.

There's two types of separator as indicated below, the actual pic provided is of the later type.

index.php
 

PlasticMac

Member
It's excessive and not uncommon to these 1.4 AUA and BBY blocks.

A big culprit is the oil separator part of the pcv system ( positive crankcase system) at the back of the engine. If these become blocked you get the oil consumption you describe.

There's two types of separator as indicated below, the actual pic provided is of the later type.

index.php
In this scenario, where does the oil go, into the inlet manifold (and so burnt?
Mac.
 
In this scenario, where does the oil go, into the inlet manifold (and so burnt?
Mac.

It's being ingested so it's logical it's being burnt.

Had the exact same problem on the 1.4, never saw any smoke out the back whatsoever but drank a lot of oil over 9K miles. Can't remember the exact amount as it's at least 3 years ago now but it was over 5 litres, it's actually written down here on the forum somewhere. I asked the forum for advice, it was only when i dug deep and investigated it has come up time and again over the years on here. One chap pulled of his pcv separator cut it in half to see it full of oil mayonaise. He replaced with new and his huge oil consumption problem was gone overnight.
 

triumphant59

New Member
It's being ingested so it's logical it's being burnt.

Had the exact same problem on the 1.4, never saw any smoke out the back whatsoever but drank a lot of oil over 9K miles. Can't remember the exact amount as it's at least 3 years ago now but it was over 5 litres, it's actually written down here on the forum somewhere. I asked the forum for advice, it was only when i dug deep and investigated it has come up time and again over the years on here. One chap pulled of his pcv separator cut it in half to see it full of oil mayonaise. He replaced with new and his huge oil consumption problem was gone overnight.
Sounds like this could be my problem.
 

RZX

A2OC Donor
It's being ingested so it's logical it's being burnt.

Had the exact same problem on the 1.4, never saw any smoke out the back whatsoever but drank a lot of oil over 9K miles. Can't remember the exact amount as it's at least 3 years ago now but it was over 5 litres, it's actually written down here on the forum somewhere. I asked the forum for advice, it was only when i dug deep and investigated it has come up time and again over the years on here. One chap pulled of his pcv separator cut it in half to see it full of oil mayonaise. He replaced with new and his huge oil consumption problem was gone overnight.
Is this an expensive job and would I be wise to get the separator change as a preventative measure rather than wait for the problem to arise.
 

66Beetle

A2OC Donor
Our 130,000 Mile 1.4 Petrol does not use any Oil since I changed from using Longlife 5w 30 to VW Specific Fully Synthetic Millers Oils Trident 5w 40. It used to burn quite a bit on the Longlife 5w 30. Also seems to have reduced the Piston Slap noise on 5w 40

Steve U
 
Sounds like this could be my problem.

It's the most likely cause but put it this way, if you replace it and it doesn't sort it out you've only spent £50 or so. These AUA and BBY blocks have been known for piston slap (google it) and seized oil control rings which means a new block because these aluminium engines can't be opened up as they distort. Audi's idea of long life oil changes at the time where some people were doing 20k miles between oil changes just exacerbates the poorly designed pistons/rings. After much moaning from customers Audi eventually dropped the veil of silence and redesigned the piston and rings.
 
Is this an expensive job and would I be wise to get the separator change as a preventative measure rather than wait for the problem to arise.

You're are bang on the right track!

I've ordered the same part for mine over a month ago now, a disappointing main dealer story, parts still not arrive yet but yes it's quite cheap for the part, you would just need someone to fit it by removing the under tray and replace part.
 
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PlasticMac

Member
It may, or may not be significant, but (from the original post) this high oil consumption only occurred after an oil change service.
For 1.5 - 2.0 LTRs of oil to pushed out of the crankcase over 2000 miles, when previous to the oil change, oil consumption was (I assume) minimal, points to something associated with that service. I don't have any detailed knowledge of the 1.4, but my thoughts turn to wrong oil? overfilling/dodgy dipstick?

@triumphant59 how did you know your oil needed topping up? Dipstick or Warning Light on the dash?
Mac..
 

PlasticMac

Member
It's excessive and not uncommon to these 1.4 AUA and BBY blocks.

A big culprit is the oil separator part of the pcv system ( positive crankcase system) at the back of the engine. If these become blocked you get the oil consumption you describe.

There's two types of separator as indicated below, the actual pic provided is of the later type.

index.php
The PCV system is to prevent harmful emissions from the crankcase breather (mainly piston blow by) being vented to atmosphere, by recirculating them via the inlet manifold. All modern cars have this system.
The crankcase vent is taken from a high point in the crankcase, well above the oil level., so, for engine oil to be burnt at an excessive rate, that oil has to be forced into that vent, With normal oil levels in the crankcase this seems, to me, to be unlikely.to happen. The oil separator is there as a safety precaution, so that in the event of oil entering the PCV system, it will be separated, and drained back into the crankcase.I don't think it's intended to deal with the sort of volumes we're talking about.
In normal operation no oil should come anywhere near the crankcase vent.
If it does, I'd look for the root cause, wrong oil/overfilling etc,
If oil is trapped in the separator, the separator return must be blocked, But even then, that doesn't explain how that much oil got there in the first place..
Mac.
 
The PCV system is to prevent harmful emissions from the crankcase breather (mainly piston blow by) being vented to atmosphere, by recirculating them via the inlet manifold. All modern cars have this system.
The crankcase vent is taken from a high point in the crankcase, well above the oil level., so, for engine oil to be burnt at an excessive rate, that oil has to be forced into that vent, With normal oil levels in the crankcase this seems, to me, to be unlikely.to happen. The oil separator is there as a safety precaution, so that in the event of oil entering the PCV system, it will be separated, and drained back into the crankcase.I don't think it's intended to deal with the sort of volumes we're talking about.
In normal operation no oil should come anywhere near the crankcase vent.
If it does, I'd look for the root cause, wrong oil/overfilling etc,
If oil is trapped in the separator, the separator return must be blocked, But even then, that doesn't explain how that much oil got there in the first place..
Mac.

You will get oil vapours in the separator and over time they build up along with carbon deposits and gum up. Long life oil regimes just encourage it. Once it becomes blocked pressure just builds up in the engine forcing oil out to burn. I always checked the oil level and never overfilled the 1.4 (Cobalt Blue). The oil level alarm would go off which was a huge surprise since the oil change was only a month before to find low oil level. This just went on and on and as you know i bought the FSI which thankfully has been a great car. So as they every cloud has a silver lining. :)
 
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