MK4 TDI Vacuum pipe

[Dieselgeek]

I pick up limp mode on the odd occasion.

Thinking of starting with vacuum pipe replacement as it is the cheapest.

From what I have read 4m of 3 mm silicone piping will be enough to do the entire car.

Has anybody done this ?

Does the 3 mm fit all fittings including the 5 mm ones?

Also I see Volkspares has the piping for R42 a metre. Is a decent price ?

[Dieselgeek]

Nobody responded to my post so I decided to go ahead and get the 3 mm vacuum hose.

Got 4 m of hose and 2 onetime only clamps from Volkspares for R180.

Took me about 30 minutes to fit as I was doing one hose at a time.

The bigger fittings took a bit of finessing but they all fitted in the end.

The most difficult one to do was the hose to the turbo actuator purely because of location.

Eventually jacked the car up and removed splash cover which made getting to the actuator quite easy.

Actuator rod was not moving as freely as I liked so i took the opportunity to lube with some power steering fluid and silicone spray.

I have about 30 cm of hose left so 4m is about right.

Some of the old hose was definitely shot.

One way check valve also tested ok.

Car pulls better and is more responsive especially at lower rpm.

Fuel consumption is also better.

After I hammer it up the N12 hill past Edenvale I will find out if limp mode is gone.

[Dieselgeek]

A pic I took after.

Still needs some neatening.

[amstel18]

First time I see this post. I see your post was over a weekend. Sometimes those posts get lost and dont show up under the new posts.

Let us know if it resolved your limp mode issues.

The vacuum piping you got, is it the one with the material braiding on the outside?

Sent from my GT-I9100 using Tapatalk 2

[jvrsvw]

these little vac pipes caused me plenty a headache when I had my G4 Tdi, there are so many and difficult to isolate which one is the culprit, also ended up replacing everything, no issues after that !

[AlexTDi]

My neighbour just did this, he paid about R52 a meter for the stock velvet type pipes

[Dieselgeek]

Hey Whabba,

Pipe quality from Volkspares is excellent.

Pushed her up N12 , no limp mode . Will keep an eye on things to make sure limp condition is gone.

If the actuator arm is not moving freely when moved by hand the vacuum pipes won't make a difference.

I would try lubricating the arm as a first resort. Some sort of penetrating spray should work. I used power steering fluid as apparently it is very good at freeing corroded parts.

If the arm still doesn't move freely then this points to the VNT vanes inside the turbo. If you intend upgrading to a bigger downpipe you can try spraying some oven cleaner into the hot side of the turbo when the old pipe is off the car. Hot side is cast iron so no chance of the cleaner eating any aluminium.

Changing the vacuum pipes won't hurt and the silicone pipes are R42 a metre, so the upgrade us cheaper than OEM as well.

[Dieselgeek]

No problem.

Picked up limp mode again yesterday. Was doing 180 up that N12 hill and had to slow down for traffic.

When I nailed it again she went into limp mode.

Will be swapping the EGR and N75 valves this weekend to discount N75 valve .

I have a sneaking suspicion that my fault also lies with the VNT vanes though.

My car is a 2003 vintage so its the same age as yours , but she rides better than the SO,s 2006 Polo TDI.

Don't think I will be selling any time soon.

[Tdi jetta 4 ever]

A pic I took after.

Still needs some neatening.

I noticed that your vent system is changed. What is the reason for that?

[Dieselgeek]

The PCV normally returns blow-by gasses into the inlet manifold. This includes oil vapour which in times causes the buildup of residue in the inlet manifold and the gunking up of the EGR valve. I have rerouted to vent to atmosphere to prevent this.

[Grimz]

Howzit Dieselgeek,

Ive had the same issue with my Jetta tdi when I first got her. Ive changed all the vac pipes, swapped the EGR and N75 valves and checked actuator arm and still had the limp mode issue. The culprit was the air-flow meter. after I changed that i've never had the issue again. 3 years now since I changed it and no limp mode issues.
you can maybe swop with someone that has a jetta tdi to test before buying a new one.

Hope that helps.

[Dieselgeek]

Hi Grimz ,

The MAF was the first thing I replaced when I bought the car , (50 000km ago) but thanks for the input.

[Grimz]

try this link guys. might just find some helpful info.

http://www.myturbodiesel.com/wiki/limp- ... di-engine/

[SilverFox]

Just replaced mine. R160 for 4 meters at Four Flat Racing. Issues started with intermittent brake assist. Had to step much harder on the brakes to stop sometimes. Could still live with that, but when the car started losing boost, it was time to replace the hoses.

[BIGMIG]

And did it sort out your issues?

[SilverFox]

All sorted.

[Fli]

Whilst I was driving on the highway my car lost brake pressure and boost.
I have a vacuum issue on a 1.9 tdi AHF engine code.
Checked the vacuum pump on the side of the head. Cleaned it and nothing.
Still no brakes or boost.

I've replaced all the vacuum lines.
When I let the car run and pull one of the vacuum lines you can hear the vacuum and also feel it.
But brakes stay hard and actuator does not engage.

On the main brake vacuum line I tested the valve as follow:
If I blow from the brakes side it stops.
If I suck from the pump side it sucks from both the small vacuum and the brake booster side.
If I blow from the pump side the air only goes out at the small vacuum pipe.

I will VagCom it tonight and see if it is N75 valve.

[CGDP]

I also got the MK4 TDI and did the vacuum pipe replacement with 3mm fuel hose. works great

[Moe10]

Hi guys
I live in jhb and i just bought my first car and its a golf 4 tdi. So i was wondering where could i get good quality heat resistant vacum pipes from? .. if im not mistaken on my car it looks theres two different diameters a 3mm and a 5mm?

[panic-mechanic]

http://www.carlinmedical.co.za/

[Mrmax2101]

Hi guys, i have read through your comments. I have 2003 audi 1.9 tdi, i think that these engines are similiar to those in the golf or polo tdi's. I also have a no boost problem and am still busy trying to resolve it. At the moment, my car is running as normal but there is no boost, prior to this it showed slight signs of boosting problema when driving at speeds between 120-160km it will jerk just for a few seconds and then will run okay thats the only signs it showed...being busy with work i just started driving slower , then just one more jerk then i could feel no more extra power. What i have done so far, clean the turbo with oven cleaner, made sure the acutator arms above the vnt valves are free and able to move, i swoped the n18 valve with the n75 valve. What i have noticed is that im not gettin any vacuum at the line that is supposed to open the vnt valves, im also planning to replace the lines even though i have checked them all of them seems to be working fine, also i cleaned the sensor on the boost pip, i think its the map sensor...any suggestions onto where to go next will be appreciated. . These motors have good balance between power delivery and economy so will like to get her back to her old self....please help!!!?

[panic-mechanic]

If you have no vacuum at any of the pipes then maybe the tandem pump is bust. Did your brakes become harder at some stage?

[Mrmax2101]

Hi, thanks for the reply. I have read about some tipe of vacuum pump, but my brakes were normal ever since the problem occured, so skipped the idea of a vacuum pump not working... what do you think? What i also forgot to mention is that the car swings longer before firing up, havent timed it but it seems like 30 seconds where normaly it will fire up much sooner. Thank you for the feedback