My Fabia saloon 1.4 16V (BBZ engine) is starting to get into the heavy oil consumption league.

Since undergoing annual service in February its done just over 2,000 miles and I've just topped-it up with a second litre of 10w-40 Magnatec semi synth - I've been topping-up with semi-synth as the engine seems to run quieter and smoother on it.

Its now done 46,000m in total - I do about 6,000 a year mainly round the North-west London suburbs.

Engine oil consumption started to increase at about 25,000 - before then it didn't require top-up between annual services.

I presume the excessive consumption is due to piston ring and/or valve stem wear.

Obviously, the consumption is a fair way away from the handbook tolerances of 1 litre per 600 miles, although i'm not getting any consequential symptoms yet, i'm just wondering whether I should expect these in the near future i.e.lambda sensors going on the blink and catalytic converter getting saturated.

Given that a head and block re-build would be at least a £1,500 i'm wondering whether one of these warranty insurances @ £200 might be worth the investment now.

Once you get oil consumption like I'm currently experiencing how long does it take before the engine reaches the 600 m = 1 litre limit ?

As I've said on previous posts, what sort of pollution is this putting into the atmosphere, with all the heavy metal supplements in modern oils ?

nick

Edited 31 July, 201015 yr by Clunkclick

Any body got comparative oil consumption figures for 1.4 16V petrol ?

Or any tales of head/block re-builds ?

Nick

This was on a 2001 AUB, but it's still a 1.4 16v if it helps at all.

Mine would use roughly the distance between the min and max on the dipstick every 1,000 - 2,000 miles or so. If you can use the Haynes or something to translate that into a quantity it might of use, but at a guess it was ~1l or so. (10l lasted about 18 months, which was around 12,000miles for me, although that included an oil change.)

The limit on oil consumption is how thick the smoke is from the exhaust and how often the plugs oil-up . The MOT stations will fail any vehicle for excessive smoke. It might be good idea to consult your car manual and see what is the highest oil viscosity that can be safely used . A thicker oil may reduce your oil consumption slightly especially when it cold . But when hot I don't think it will make huge difference. The police will always pull over a vehcle that has excess smoke.

I once overfilled my kid's old escort in the dark and was pulled over for having a smoke screen that blotted out 4 lanes of the motorway with thick blue smoke - looking back it was like a destroyer smoke screen ! They let me off with a warning because the car was so old ! But even with all that smoke it still ran ! Happy days !

I suspect that the molecule size of the semi-synthetic oil is smaller than that of ordinary refined engine oil. So you may get more "Blow-by".

The wear problem is obviously still there, but switching back to straight refined Castrol GTX on top-ups might delay the fatal day.

I still think that the viscosity of today's engine oils (10w-40) is too light for the Fab engine, even though that's what's specified.

If 20w-50 were available retail I would be inclined to use that and I'm sure that the oil consumption problem would disappear. Obviously fuel consumption would go up.

In my youth 10w-40 was regarded as sewing-machine oil, used only in Jap motorcycle engines. These engines had a life span of 30,000 miles !

Nick

Edited 1 August, 201015 yr by Clunkclick

Just found a compromise oil.

Millers XFS 5w-50 @ £34 per 5 litres. A fully synthetic oil which meets the VW 501.01 oil specification applicable to the 100HP 16v engine.

The "50" part means that it has higher viscosity at a temperature of 100 degrees centigrade.

However, my use pattern is predominantly short journeys, so I would expect the majority of the oil loss to be at lower engine temperatures.

I'll have a further look on the net to see what the vicosity profile of this oil is over lower temps.

Postscript

The millers oil has a wider range of viscosity (5w-50) than comparable fully synthetic Mobile 1 (5W-30). However the Viscosity index (VI) (The ability of the oil to adjust viscosity to temperature/pressure) is lower than mobil 1 - 140 to 165 (The higher the VI the more adjustable the oil is). Presume that this is due to the top-end characteristics of the Millers i.e in the range 30-50 SAE.

I think its going to be trial and error

Nick

Nick

Edited 1 August, 201015 yr by Clunkclick

Halfords is one source for 20w 50 http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_166289_langId_-1_categoryId_165581#dtab that meets some sort of specs. If you don't mind it not meeting specs then theres the cheap stuff in Wilkinsons, Asda, Morrisons.

For info I never had to top up the oil on my former 2004 vRS between services except once at around 6,000 miles. That's none at all between 6,000 miles and 64,500 miles...

For info I never had to top up the oil on my former 2004 vRS between services except once at around 6,000 miles. That's none at all between 6,000 miles and 64,500 miles...

Cheers. Thought as much.

I can't believe that its just the oil control rings that have gone. It must be the gas rings and possibly the valve gear.

I've asked the garage to check the compression in the past and they've come back and said its OK. I think i'll get a screw on meter and test it myself.

If , with the plugs out, the compression pressure pick's up after one or two revolutions of the engine then its the rings, if it doesn't pick-up at all then its the valves.

Nick

Edited 1 August, 201015 yr by Clunkclick

My first car was a 1982 polo 1.1 litre 8V engine, mileage ~ 100k. It would use a litre of oil in 300 miles and put out a plume of smoke that was visible in the rear view mirror when accelerating and on overrun.

Looking in the exhaust and inlet ports you could see oil running down the valve stems. I took the head to a small local cylinder head specialist, they stripped it, cleaned it, fitted and reamed new valve guides, and rebuilt it all for £100 (that was 15 years ago). The guides were so worn that the valves would rock from side to side when we took the springs off.

I also replaced the rings and big end shells whilst I had it apart, they were sourced by a local motor factors at a very reasonable rate. I didn't have any measuring instruments but the bores looked OK so I just cleaned them up.

A fabia 1.4 16v will obviously cost more to rebuild, having twice as many valves but the principle is exactly the same.

After the rebuild it never used any oil.

Edited 2 August, 201015 yr by bnjyn

I am prepared to bet money that a THOROUGH clean of the crankcase breather system will bring the consumption way down.

I am using 5w-30 full synthetic in my BBZ engine and it does not consume any at all(it is what Castrol and Opie Oils recommend for this engine), so I will presume the blow by is not because the "today" 10w-40 is too light(is more like "yesterday" oil). Crankcase breather system might be the problem.

I am prepared to bet money that a THOROUGH clean of the crankcase breather system will bring the consumption way down.

What's the theory behind that then ? Is it that if the breather's blocked, it increases the crankcase pressure and that this pushes oil into the upper cylinder during the piston induction stroke ? Surely this would be repelled on the exhaust stroke ? The engine on my Fab has a 10:1 compression ratio so that I would have thought this, even with a worn engine, would have militated against oil migration.

In fact this article seems to suggest that the coarser the tolerances on the rings the less likely there is to be oil loss and vicky verky and that oil loss is at a greater rate at moderate (running round town) engine revolutions ?????:-

http://www.ricardo.com/Documents/Downloads/pdf/ringpack_lube_oil_consumption.pdf

Don't the crankcase breather's of today's engines vent into the Exhaust Gas re-Circulation system ? So, if the EGR is U/S or obstructed, crankcase pressure could rise and oil loss increase.

Surprise! Surprise ! I've just had the EGR valve assembly cleaned and been told that it will need replacement - may that's the cause

Nick

Edited 5 August, 201015 yr by Clunkclick

For some reason these engines are very sensitive to a dirty crankcase breather system, it runs from the top of the crankcase and vents though the air filter into the intake, not directly into the egr system. Yes it does prevent over pressurisation of the crankcase which forces oil past the control rings.

I bought mine at 48k miles it was using a fair bit of oil. I cleaned out some of the breather and used an engine flush and things got better. I left it for a while, did a complete strip down clean of the breather system (couple of hours), and things got much better. I change the oil and clean the breather system every 5k miles, have now done 89k miles and it uses approx 1 pint in between oil changes.

I also think that the oil control rings are prone to sludging, (not always piston ring failure as everyone says), so careful use of flushing oil could help, but there is no substitute for clean oil.

Wife's Polo 9N with the BBY engine and 68,000 miles uses a bit of oil, maybe 0.5 litre every 1,000 > 2,000 miles its always had fully synthetic 5-40 - more recently changed from Synta Gold to Fuchs Titan SL 5-40. I'd reckon that the Castrol weight of 5-30 is suggested as that is what most Fords etc need and it makes life easier for stockists if that weight is seen as a "standard". Though, it does seem that VAG is itself now using lighter weight oils so does tend to specify 5-30 for most new petrol engines.

The one for Ford is a 5w-30 special one(Magnatec 5w-30 for Ford) with ACEA A1. The one for Vw is castrol Edge 5w-30 and is VW504/507 full synthetic and will give less sludge than the semi 10w-40.

Checked the oil this evening.

Looks like it just used 0.5 litre since the last top-up on 29th July. That's only 376 miles covered. At that rate i will be using 1 litre for 752 miles. So just within limits.

The rate of usuage seems to have increased. From the annual service in February to 29th July it used 2 litres and covered 2051 miles. So rate then was just over 1000 miles per litre.

Mind you. I have been topping-up with 10w-40 magnatec semi synth per the handbook spec. I suspect that the dealer may fill it with straight refined 10w-40.

Did an extensive check in the engine bay and underneath using an inspection lamp to see if there were any leaks - nothing found.

Examined the exhaust pipe exit and whilst it had a minmal covering of black sooty carbon it was only a thin layer and was not noticeably oily. I have had the aircon on today and I've noticed that that tends lead to overfuelling of the engine. So that may account for some of the soot.

Though, i have to say that the old Golf Mk 1 I owned previously, always had a light grey colouring to the exhaust pipe exit, never had to be topped-up between services, ran on 20w-50 and did 32MPG.

Postscript

Just been on two weeks hols to Brittany in the Fabia. Topped-up with Castrol Magnatec semi-Synth 10w-40 before I left - in fact overfilled slightly, so that the EM light came on within two miles of me setting off, engine temp was normal all the time, so I pushed on. EM light didn't go out until I restarted the engine to get off the ferry on the over side of the channel !. On the outbound leg I covered 300 miles (UK & France) and it used 1/2 litre of oil - level was half way down braided area on dispstick. Did a couple of hundred miles whilst in France - used practically nothing. On the return leg, I topped-up to the dipstick max with Magnatec (Took some with me) before I left and did 212 miles. It used about a third of a litre. Obviously on the outbound and return legs it was fully loaded with camping stuff and a loaded roof box, whilst it only had an empty roof box when running around in France.

Extrapolating these figures, then its using about a litre every 600 miles which is outside the manufacturers limits - so why aren't the EM lights on all the time ?

Is it possible that its leaking through the crankshaft oil seal into the clutch bell housing ?

Whilst in France, I took the opportunity to take the plastic "lid" off the engine and looked for oil leaks on the engine topside (I'd already previously checked underneath and found nothing) and checked the air filter and the crankcase breather - all clean as a whistle.

Where the smegging 'ell is it all going ?

Nick

Edited 14 September, 201015 yr by Clunkclick

See postcript above.

Checked the oil yesterday. No oil appears to have been used since I returned from hols a month ago.

Must have done at least 400 miles since then.

Very peculiar. I wonder whether the engine breather tube was pinched and that removal and re-installtion of the air cl;eaner when I was on hols removed the constriction.

Had a couple of major events while driving - Engine loosing power momentarily and the rev counter descending rapidily and bumping off the stop. Seems to be a silent back fire. Can't make my mind up whther its the EGR valve or a sticking cylinder valve. Usually occurs, when engine is below 2000 RPM and under vacuum advance at the start of a hill. Also engine can cough a little first thing in the morning, though not always, when running on "Choke" at under 2000 RPM.

Nick