Turbo Underboost??

[Hardehout]

The Touran experiences a sudden loss in power on long uphill stretches. The only remedy after this occurs is to stop and switch the car off and on. No engine lights come on.

I had a local dealer do a fault check and it states an under boost error. Unplugged the mass airflow sensor but the problem occurred again.

Error Code on VAS 5052A is 00665 or P0299.

(How do I add a picture of the error code?)

[Hardehout]

Hi Guys,

I have found the following possible causes and fixes on the myturbodiesel forum. Did some checking around on 1 and 2.

1.Small boost leak - Check integrity of the system using a vacuum pump
[I saw guys on youtube doing a vacuum check with a self build pump but I do not have the skills for that. My local where I service my car also do not know how to do it. Not yet asked VW if they can do it]

2. Diverter Valve - Check
[According to VW the diverter valve cannot be exchanged without buying a complete turbo unit.]

3. Wastegate bypass regulator valve
4. Mechanical Turbo Damage - check turbo charger
5. Faulty Charge Air Pressure sensor/control - check/clean/replace charge pressure control (Clean the EGR Valve).
[Not spent any time on 3-5]

I need advice on where to start to diagnose the problem. Who can I use to assist me to do proper fault finding and assist to fix the problem. I live in PTA.
I am not sure the exact engine model. It is a Touran 2006 1.9Tdi DSG. In the manual it says 77KW BLS.

[Neuk]

I would start with a boost leak check just to be on the safe side, although I am not convinced this will be your issue as it would cause problems all the time and not just on uphill stretches. It sounds to me like you have an issue that when the car is under heavy load, causes the under boost and the ECU to go in to limp mode. The under boost could be caused by a boost leak but also by sticky vanes in the VNT system, a malfunctioning vacuum system, either a leak or an actuator sticky or broken...

Your Touran has the 1.9TDi engine which does not have a DV or wastegate so you can rule these out immediatley. Boost is controlled by a VNT system which can give issues in higher mileage engines...

[LoW n SloW]

check for leaks, if not leaks
check for that black vacuum box

[neighbourhood terror]

As has been said check for vacuum leaks. The vacuum pump sits on the right of the head and is part of the high pressure diesel pump, there will be one thick line that comes out of it and then splits at a one way valve, big line carries onto break boosted and then a small 5mm line goes to the vacuum distribution box. Check and trace all the hoses and make sure they're in good condition. Check the vacuum reservoir for damage or cracks, its the big black round job that's on the front of the motor.

A leaky or faulty EGR will bypass exhaust gas away from the turbo and into the intake which will cause loss of boost pressure., unless the turbo is whining excessively or making any other noises I doubt it's going to be turbo related. Check the vacuum line to the VNT actuator for leaks, the Turbo chargers boost pressure is controlled by this line and the VNT actuator. From underneath it's easy to spot will be the big silver chamber with a diaphragm inside, disconnect the pipe and attach a piece of vacuum pipe and suck on it, it should move the VNT actuator smoothly and not leak.

[Hardehout]

Thanks for all the advice. I will tackle this step by step in the new year.

Would anyone know of a proper place to service the Touran in Pretoria?

[JanDeere]

Did my clutch at Hatwagen in Silverton, think they are RMI approved, maybe phone them for a quote. All the places are probably closed until the 5th of Jan tho

[Hardehout]

Hi Guys,

Finally had the car with VW and they where very helpful.

There is nothing mechanically wrong with the turbo itself.

It is the EGR. Apparently it is clogged up, this caused the unit to overheat and cause damage to the pc board of the EGR.

Part cost R 7700
Labour R 3500

What do you guys think? Will a carbon clean solve the issue or should I replace the unit?

[Whipme]

Wow, scary numbers. I've got the same issue on my 2006 1.9 golf, but I'm at 270k km so I'm pretty sure it's the EGR clogged up or VNT vanes sticking. A motor industry friend of mine suggested Steve's auto clinic in Boksburg so I'm going to try them in a week or two. Alternatively, I might just go to carbon doctor in Pretoria

[Hardehout]

Phoned Goldwagen and they quoted me R 1700 for the part.

I had a look at the quote I received from George at Carbon Doctor. It is R3800 for the valves, ports, intake manifold and the EGR valve.

I will have to give George a call then.

[SykomantiS]

Can these 1.9 TDI engines run with a blocked EGR valve? Or will it throw an error code? (blocked as in blanked off with a blanking plate)
If it won't throw a code, block it and be done with it. I wish I could do it on my car (mine would throw error codes however).

[Neuk]

Can these 1.9 TDI engines run with a blocked EGR valve? Or will it throw an error code? (blocked as in blanked off with a blanking plate)
If it won't throw a code, block it and be done with it. I wish I could do it on my car (mine would throw error codes however).

They can but that will cause a CEL which either needs to be coded out or the ECU tricked in to thinking the EGR is still functioning...

[SykomantiS]

Ok, so easy answer is no then- I'm in the same boat.
I'm not sure about part cost but isn't that labour price a bit excessive?

[supervly]

So if it was me i would take the unit off and replace - clean the intake manifold and the pipe between turbo and egr

There are many references on you tube how to do it - it is really not that hard , its just quite a messy job

https://www.youtube.com/watch?v=cCjO8JThVpo

https://www.youtube.com/watch?v=5OQ8-36A9gw

[Whipme]

Phoned Goldwagen and they quoted me R 1700 for the part.

I had a look at the quote I received from George at Carbon Doctor. It is R3800 for the valves, ports, intake manifold and the EGR valve.

I will have to give George a call then.

Which branch of Carbon Doctor is that from? Because the Pretoria branch told me they don't do diesels, and the joburg branch told me they don't do EGR's

[BatteryWorldPtaEast]

Hi , I have a Touran and have the EGR completely removed and blocked off with no problems .

Do you know if the car has been remapped / software ?

Hope it helps.

Hennie
(Mine is remapped by Trevor Green)

[Hardehout]

I took the vehicle to Frans of http://vagspeccentre.co.za/ last week. He is confident that it is not the EGR as he has never replaced an EGR on a Touran.

It also cannot be a boost issue as it would happen in different driving and load conditions on the engine.

The only thing that is left is the turbo.

[G_Power]

I'm having a similar problem (amongst others) with my golf 5 TDI (engine code BKC) I suspect a faulty MAF. I've pinched one off a Touran that isn't being used at the most. I'll let you know if this fixes the problem.

[G_Power]

@Hardehout.
I figured out that my car was dropping into limp mode, sounds like yours is too. Almost definately related to breathing issues.

As suggested get the EGR cleaned (it's really not that difficult, just dirty and fiddly), I would also recommend getting rid of the CAT (has made a huge difference on my car).

If the car is driving normally at first and not making any funny noises then it is unlikely to be a problem with the turbo.

Not sure if the MAF had anything to do with my problems as both cars seem fine.

Hope this helps

[Whipme]

Did you do the EGR cleaning yourself? How easy is it to get it off the engine?

[G_Power]

Did it myself, I also took off the inlet manifold as it was pretty sooted up as well.

Like I (and others) have said it's not that difficult just fiddley and access is a bit tight.

I scraped out as much gunk as I could and then soaked it in oven cleaner, then a pressure wash and some detergent. Like I said it's a messy job.

[dietrs@gmail.com]

Hi Guys

I have a similar problem on my 2009 2.0TDi Tiguan but tested the vacuum line and found the actuator leaking vacuum. I assume it is a big job to replace the actuator but where do I find one? Any good turbo workshops that anyone can recommend to replace?

Thanks for your help.

Dietrich

[panic-mechanic]

Actuator you can try from either goldwagen or vw themselves. The turbo sits at the back. Possible to get to it. Just fiddly. Don't need a specialised turbo shop for it.
Again asks for recommendation but supplies no location....

[dietrs@gmail.com]

Thanks for the advice Stephan! Will give Goldwagen a try.

I am in Centurion, sorry...

[panic-mechanic]

possibly some centurion guys will give you a reference. I have one but some negative remarks will be made by some people so will just not bother.