Mk4 Golf 1.4 petrol - Oil consumption

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Sat 19 Nov 2011 21:37
Mk4 Golf 1.4 petrol - Oil consumption - golf-driver

I have a Mk4 Golf 1.4 petrol engine thats done 126k.

The engine consumes 1 litre of oil after driving 850 miles, is this normal or should something be done. There are no oil leaks.

Occasionally when the engine has been idling for a while in neutral when I pull away using the throttle a load of white/blue smoke is emitted from the exhaust, this is more pronounced when climing an incline.

Apart from this the engine doesn't emit any white/blue smoke.

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Sat 19 Nov 2011 22:42
Mk4 Golf 1.4 petrol - Oil consumption - Big John

I have a 2001 Octavia 1.4 which has the same engine setup . I had the same issue a couple years ago and researched that these engines suffer from oil breather issues causing the engine crankcase to become pressurized blowing oil past the valve oil seals.

Presuming yours is the same as mine (all the ones I have seen are) and it has an air filter housing between the top of the engine and the bulkhead. Try two things:-

1) Standing at the front of the car the oil breather pipe feeds into the air filter assembly to the left. Remove the oil filler cap and disconnect the breather pipe from the air filter - try blowing down it - If flow is very restricted then the oil breather assembly bolted to the rear of the engine is probably blocked. (Make sure the oil filler cap is removed for this test if not it will feel restricted anyway - unless you engine is really really worn)

2) If 1) above is OK then remove the air filter assembly and take off the cover. Inside you will see an internal plastic pipe running from the oil breather pipe input through to a mushroom valve (rubber flap). This pipe blocks with oil mayonnaise due to condensation. Clean out thoroughly (I used turps to help).

Mine was badly affected by 2) - I now clean it out once every other year. Oil consumption now much much better.

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Sun 20 Nov 2011 18:31
Mk4 Golf 1.4 petrol - Oil consumption - golf-driver

Thanks for the advice. That internal plastic pipe inside the air filter assembly cover was blocked with mayonnaise.

In fact the short section from the oil breather pipe input to the rubber flap and the long section behind the rubber flap were blocked with mayonnaise. There was actually some near the carb input.

To clean the long section (rubber flap to carb input) I was able to divide in half. I did notice that the rubber flap was in a fairly poor state, there was a perforated hole.

What is the purpose of the rubber flap? Does it matter if it's got a hole?

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Sun 20 Nov 2011 22:26
Mk4 Golf 1.4 petrol - Oil consumption - Big John

"What is the purpose of the rubber flap? Does it matter if it's got a hole?"

Not sure what the flap is for, probably to ensure most of the engine air intake comes via the air filter/outside world. With 125k miles on the clock your engine will probably have enough wear on it to ensure that you always have positive crankcase pressure though. Mine has about 100k on it and when warmed up if you disconnect the breather pipe you can feel a gentle but steady output.

To be honest I don't think the rubber flap was in great nick on mine.

If you are not doing so already I would recommend running this engine on super unleaded - they are prone to pre-ignition on 95 RON petrol which can cause piston damage. Can't have been a previous big issue on your car as it has 125k on it!! I usually find that on mine the extra cost is "nearly" offset by improved economy especially on a long run.

If you get a rattle on a cold morning on startup it is probably piston slap - they all seem to do it as they have very small light pistons. Mine started doing this at 30k.

Also keep an eye on the nuts securing the EGR valve on the front of the engine to the right hand side of the exhaust manifold (If fitted - some earlier 1.4 16v MkIV Golfs didn't have them) - They can rust up so it is worth spraying plusgas or WD40 on the threads every now and again as sooner rather that later they will need to be undone as the EGR valve is prone to failure (Throws up engine management light - code "insufficient flow") . Easy job if you can undue the nuts.

Generally though from new I have had so little trouble with this car other than the usual service items and the above (+ a couple of suspension springs) I'm reluctant to get rid of it even though it is nearly 11 years old now.

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Tue 22 Nov 2011 22:24
Mk4 Golf 1.4 petrol - Oil consumption - golf-driver

Thanks again for the detailed advice.

Yes I also get that piston slap on start up, it sounds like a diesel engine for a short while.

Regarding the breather hose, why not just leave it disconnected from the air filter assembly, that way it won't add oil to the assembly.

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Tue 22 Nov 2011 23:07
Mk4 Golf 1.4 petrol - Oil consumption - Big John

I am afraid this would be dangerous and smelly as oily exhaust fumes would get into the car. It's also illegal.

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Tue 13 Nov 2012 14:32
Mk4 Golf 1.4 petrol - Oil consumption - skidpan

Regarding the breather hose, why not just leave it disconnected from the air filter assembly, that way it won't add oil to the assembly.

Would you really want to deposit oil on a wet road for a motorcyclist to crash on.

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Wed 14 Nov 2012 16:10
Mk4 Golf 1.4 petrol - Oil consumption - unthrottled

Mine has about 100k on it and when warmed up if you disconnect the breather pipe you can feel a gentle but steady output.

That doesn't sound right. The breather hose can act as a inlet or outlet depending on the position of the PCV valve and inlet manifold pressure.

Under manifold vacuum, the PCV allows manifiold vacuum to draw out crankcase gases, and fresh air enters via the breather hose. Under full throttle, the PCV is useless and the crankcase pressure is expelled via the breather hose.

Properly functioning breather systems reduce oil consumption and emissions whilst increasing oil life. Cheap to fix and worth doing.

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Tue 13 Nov 2012 13:54
Mk4 Golf 1.4 petrol - Oil consumption - rezart

Hi Big John,

Some picture ilustrations of the components you mention, would be of immense help.

Thank you in advance,

Rezart

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Wed 14 Nov 2012 16:00
Mk4 Golf 1.4 petrol - Oil consumption - Crasher

Leaving the oil breather off first off all is technically illegal as crankcase fumes have to be recycled since around the 1970's and also the fumes gather under the bonnet and get drawn into the heater intake and makes the car stink inside plus the fumes are quite dangerous.

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