Vacuum leak help

[metako]

My wife's 2.0 litre FSI non-turbo Golf V suddenly has a very bad idle which is giving an error message of 008825-leak in air intake system P2279-008-MIL ON, plus 000768-random/multiple cylinder misfire detected and 000769-cylinder 1 misfire.

I've done a search for these error codes and looks like it often points to a leaking PCV valve but if I remove the oil cap it stumbles and almost cuts out so probably not the PCV (?). Any better way to test the PCV valve?

I attached a DIY smoke machine I have to a vacuum input on the throttle body and there are wisps of smoke coming from deep down in the areas marked on the attached pic, underneath intake manifold runner Nr 1 but I can't pinpont the exact souce as there's too much in the way. Is there anything in this area that commonly springs a leak? Where does the long rubber vacuum hose in the middle of the pic attach to at the lower end, and is this a common place for a leak to occur? (We replaced the little plastic hose from the PCV valve a few months ago and looks like its still ok.)

This is the only area which is showing smoke with the smoke tester. Any ideas?

[metako]

I found a guide to intake manifold removal and it looks fairly straightforward so might have to do that to find the source of the leak.

Volkswagen Workshop Manuals > Golf Mk5 > Power unit > 4-cylinder injection engine (2.0 l engine, direct injection) > Mixture preparation system, electronic inj.,Gas > Injection system > Removing and installing intake manifold

[JustCruisn]

Pipe on left is the crank breather, runs up to PCV. I had this broken at the bottom and then everywhere once I touched it.
It has a spring clip on the bottom end, if you have some really long needle pliers you can get it out. For me the pipe broke so then I could just look down at the bit remaining and pull it out. I replaced it but was never able to get a clamp on the bottom, it is a snug fit and certainly fixed my vac leak.
This part Topran Valve Cover Breather Hose 116 346 Topran for Audi VW Skoda | Run Auto Parts

[JustCruisn]

Wow that intake removal look really easy. I've always been too scared to pull it. I though injectors would come out, and they need new seals and special tools. Then you could remove the fuel pump to check the tappet, then check for carbon **** in the intake.

[MEL744]

Not sure what happened to my post. It was:

Removing and reinstalling the intake manifold is not too bad at all. The main problem is the hose clamps that hold the rubber pipes that go to each cylinder. They are called Clic-R hose clamps and are extremely hard to put back together using standard tools (took me about 4 hours the first time!). I believe you can get special pliers for them, or you could replace them with standard hose clamps I guess.

[metako]

Justcruisin: thanks for the info re removing the hose - so that hose you linked to is def the longer rubber one on the left in the pic and not the plastic one on the right? Relieved to hear I may be able to remove it without taking the manifold off (I've got some really long needle nose plier.)

MEL744: thanks for the info on the intake removal and the clamps. May be worth me buying the special pliers if it'll save 4 hours work! I'm new to Golfs so I'm surprised how easy the removal sounds and looks.

[MEL744]

Yep I've just been having a look on eBay and it seems you can get them for as low as $20, so would definitely be worth it. Also, since the dipstick tube is attached to the manifold, when I pulled the manifold up, the dipstick tube broke off at the bottom. The plastic had become extremely brittle at the base where it is constantly heat cycled. It could be because I was doing something wrong I can't quite remember. From memory the top of the tube is held in place by a press fit rubber gasket type thing (you can see it from above its right at the top), maybe this had become stuck in place so you could try prying it free beforehand. Just something to be aware of.

[metako]

Thanks for the tip re the dipstick MEL744 - very useful. Also, how are the clamps undone on the rubber runners? Haven't come across that type of clamp before. Thanks again.

[MEL744]

No problem, which clamps are you referring to, the Clic ones?

[metako]

yes correct.

[MEL744]

You can undo them with normal pliers, you just have to squeeze them together a bit and kind of twist. They are very springy though and will shoot off when undone. Apparently the special pliers can be used to undo them.

[JustCruisn]

Yes the left pipe, it is actually some plastic not rubber, it has very specific shape to clear all the bits down there. yes if you get off with pliers you will never get the clip back on with the intake in place.
The pipe to the right could just as easily break too, but is a lot easier to get at to check.

Can I ask what engine code you have in the Golf ? Mine is a Jetta so could be different.

[metako]

Thanks MEL744, I'll be careful when I take them apart.

Its a BLR engine, JustCruisn. Looks like I'll be taking the intake manifold off then. I've already replaced the smaller plastic hose on the right. I could not believe how thin the plastic was, and was suprised it lasted 100,000km. Thanks again.

[JustCruisn]

Its a BLR engine, JustCruisn.

Mine is BVY. I wonder if any difference with the intake. I'll have a good look in a few weeks when oil change is due.
MEL744 has BVY also, and seems to be no real issues other than the dipstick and having the correct tools.

[metako]

That engine layout looks very similar to our BLR. I started on the removal process yesterday and its becoming obvious that the online manual has missed out quite a few steps. like removal of the EGR metal pipe connection to the throttle body, as well as disconnecting the coolant hose to the throttle body etc.

I also have a new question: the manual says remove one bolt from the airfilter box on the LH side and lift it out, but ours is still being held by another stud/bolt on the RH side as shown in the picture. The stud is surrounded by a star-shaped rubber washer and there is no nut to undo, so I am wondering how this is removed? It doesn't want to lift up and I didn't want to force it as it appears many fittings on this car are quite fragile.