Golf Mk3 1.8 ´96 AAM Estate - Location of the crankcase breathing system?

[golfrace]

Hey,

could someone please point me out where is the crankcase breather system located? Is it a metal pipe in front of the engine going into the engine?

[itavaltalainen]

Welcome to the forum!

Marked it on the image below.

[golfrace]

Thanks for that!

Btw, I read your DIY about gasket replacing... it leaks alot and also that pipe! Could that cause a bad idle when the pipe is full of dirt and also a gasket leak?

[itavaltalainen]

If it is blocked the pressure in the crankcase cannot normalise, this can cause issues with running. If it leaks air can enter, this is being sucked into the engine, but since it does not come from the main intake and is hence not measured the ECU does not know it's there, which throws the mixture off.

Often the seal from the pipe is perished which is why it leaks, think from memory that was a 19.6x3.6mm O-ring. If the actual breather (the thing the pipe is attached to at front of engine) is leaking you should replace the seals at the back of it too. There are two - one green O-ring on the left side and I think the other one was a gasket (done it on my old 2E engine when I lived in Finland a long time ago so not 100% sure, could be just another o-ring).

As for the rocker gasket, just replace it. The part itself is so cheap and it's so quick to change.... It only took me 45 minutes when I did the guide - and that is with taking all these photos (taking gloves off to do so) and getting tools out.

[golfrace]

Thanks for your answer

How possible is that the MAF sensor is causing idle problems (is that the one which is located in north side of the air filter box?)? I actually disconnected the cable and it didn´t cause any difference.

Couple of weeks ago I replaced the throttle body flange (it was totally ripped), still, nothing got better.

Diagnostics showed nothing at all and it doesn´t take too much gas also, perhaps 7-8l /100km. I also replaced temp. sensor and it is fine.

Perhaps the intake manifold´s gasket is bad and lets some extra air in?

[itavaltalainen]

How many kilometers has the engine done already??

Have you checked the throttle idle control? It has plastic gears, they can break, which causes lumpy idle (as it cannot open the throttle correctly and will overshoot.
Intake gasket is possible but leaked in air is fairly small. You can try to open the oil filler cap with the engine running, if the engine then stops or runs rough you probably have no (or only a very small) air leak.

If the engine continues to run quite OK then you have a bigger air leak (and total volume of unmeasured large amount air from the oil filler plus the other leak(s) does not change too much as a percentage of whole air taken in) or the crank breather pipe is so blocked that it does not work at all anymore (if that's where the leak is).

MAFs on AAM, ANN, ABS and ADZ engines on the Mk3 are not very prone to failure... never had one of them act up.

[golfrace]

It shows 250 000 but it´s probably a lot more

[golfrace]

You have any pics about throttle valve control? Perhaps ETKA image?

[itavaltalainen]

No ETKA images... they don't really show much anyway since they only depict the whole monotronic unit.

Throttle body actuator...


Internal gearing...



250.000km? Does the speedo still show "TOTAL"? Mine did not, only showed 80.000 in the end = 380.000

[golfrace]

If they are trite is it possible to buy these parts? I mean they are specific details and definitely not the first hand parts