Leon 1.9Tdi Problem

[aymen_a22]

Just spent most of today taking the EGR and intake manifold off the car and cleaning them (I got some engine degreaser from the pound shop and it works a treat!!!!). I have also blocked the vacuum line to the EGR (both at the EGR and on the hose) and when I turned the engine on there was no light so I am going to take it for a spin later and see if the engine goes into limp mode or not.

I will let you know how I get on

 

[aymen_a22]

Just been out for a spin and it does seem to pick up a little quicker however the engine is still going into limp mode. I think it is happening if I shift quickly and don't come off the accelerator earlier enough. I don't know whether to try 10K Boost or drop the turbo and do it myself.

Any more ideas please?

PS I recommend the EGR Vacuum pipe block, it hasn't thrown a code and it has to be better for the engine (ASV Engine Code)

 

[krisby]

I was hesitant too about putting stuff through my engine, but I'm glad I did, and it was cheap, even if it doesn't fix it entirely, atleast you've cleaned (or made a start, depending on how bad your turbo is) the innards. It was not my ultimate problem, but the car stopped blowing smoke under acceleration, and the amount of smoke when starting the engine cold was halved, atleast, IMO, it's worth it either way.

 

[aymen_a22]

Does the turbo not allow full boost until the engine is fully warm? I have noticed that the engine is getting better but it does go into limp mode every now and then.

I have noticed that the VNT actuator is not moving very smoothly so I am pretty sure it is the VNT system. I am waiting for a good time to drop the turbo and clean it out and I am hoping that it will not be too difficult.

Any tips on when I take turbo out? Does the inlet manifold have to come off yet again and do I have to replace the oil lines?

 

[krisby]

correct, I don't think it allows full boost until up to temperature.

Have you tried ecotek or 10k boost? no point dropping the turbo if you haven't tried cleaning it the cheap way first.

 

[sssstew]

i have not seen any documents specifically saying that VAG TDIs reduce boost when cold, as far as im aware they provide full performance from the start.

 

[krisby]

neither have I, but I am sure some posts on these boards have suggested it, even some reporting performance problems, then everything being fine after a thermostat replacement, suggesting thermo was reporting the wrong temp, thus the ECU was restricting boost, not sure if that is true, only what I have read.

Also, I know my car does not feel like it is on full boost until the temp gauge starts moving off 60.

 

[SEATgod]

It does sound like your turbo vanes are sticking...running a cleaner behind them will not help as it will be burnt in the combustion phase before it hits the impeller housing.

This problem does get worse as the turbo gets hotter as the unit and vanes etc expand and start to stick.

Easiest way to test it is to get the car hot, then use a miti-vac gauge to pull a vacuum on the vvt actuator, it should start moving at 250 mBar of vacuum and be fully distended at 800 mBar. Then as you SLOWLY release the vacuum it should return smoothly, there is a workscope available for this to completely strip the VVT elements.

All VWG cars allow full boost from cold, the thermostat will have nothing to do with the running of the engine. I would concentrate on your turbo.

The inlet manifold will have to come off again!

Or where are you based?

 

[aymen_a22]

Thanks for the help I am located in Christchurch Dorset (quite lucky I have Turbo Dynamics round the corner from me). I don't have access to a Miti-Vac so i might just strip it down as I tried spraying the VNT actuator with GT-85 and that has not really done anything. I then tried sucking the vacuum tube to the VNT and it moved a tiny amount. Finally I got a screw driver on it and it hardly moved to I think I will get back down there to it and have a little fiddle.

 

[SEATgod]

I think your best bet would be to remove the turbo and get Turbo Dynamics to service it for you.

They will strip the variable vanes and chemically clean them, strip and inspect the turbo, advise on bearing wear. They will normally fly test it and VSR test it too.

If you have never stripped one before then it can be a pain and tbh you will never get it as clean as it needs to be with household products.

If you just wanted the vane assembly cleaned and didnt want to pay them the money, give me a shout on PM and I will let you know what I can do!

 

[aymen_a22]

Well I went to them and spoke to them a coupe of weeks ago and they told me that the turbo could not be dismantled at home as the turbine would have to be removed. This is not true at all which has made me doubt them slightly. I understand that they are the experts however the variable vane technology is not that new and the guy I spoke to was not very helpful, to be precise he tried to sell me a new unit!

Thank you for the advice though, I think I will consider removing the turbo to clean it, just when I have a little more money

 

[aymen_a22]

I have been fiddling with the car and have spotted that the cir-clip holding the VNT actuator onto the lever was missing which I think is what was partly causing the problem.

I also tried a method recommended by someone on the vw mkivs forum which was to put oven cleaner into the turbo via the EGR outlet, leave this to do its work while moving the lever until it becomes free. This worked a treat for me and I believe everything is working perfectly at the moment. I will let you know if the problem comes back.

Thanks for the help.

 

[allh2k]

Just been out for a spin and it does seem to pick up a little quicker however the engine is still going into limp mode. I think it is happening if I shift quickly and don't come off the accelerator earlier enough. I don't know whether to try 10K Boost or drop the turbo and do it myself.

Any more ideas please?

PS I recommend the EGR Vacuum pipe block, it hasn't thrown a code and it has to be better for the engine (ASV Engine Code)

Have you reset the ecu (take battery off for 1 hr) ?

just wondering if it will show a fault after this.