Strange loss of power and cruise control

[h100vw]

That might work Miro. Assuming the family aren't hogging my time. I'll give you a shout Friday night.

Gavin

[Dyldo]

well took my ride to VW service centre and it appears to be an overboost error code. They called me and grilled me on my "aftermarket mods and chip" (I don't have any, and she's never been chipped) and said it was throwing overboost error codes.

What throws these codes? As in, what causes the overboost? Part failure or ECU failure?

[Dyldo]

i'm less than 3 years and 100,000km too so no probs with warranty yay

She'll be going straight on the market though as she has done her dash with the wife. Boss-lady now wants a RAV4 it seems as the Touareg is too big and the Tiguan too small. Seems like a perfect case for a Touran but alas, no AUSDM delivery. boo.

Last time these guys had to replace a gateway control module they took about 3 weeks. Hope they are quicker with this.

Incidentally, if the overboost is sticking vanes, is it a replacement turbo or replacement vanes? I've seen reports that the turbos in the BKD are non-serviceable.

[ForceFed]

Mine goes to VW tomorrow. I am hoping it is just some overboost error codes. I to have the BKD model. Any who its under used car warranty and i'm sure they'll sort it out. Will keep you posted on the diagnosis.

[Dyldo]

Yup, I will do the same. Dealer called me again to tell me it was overboost. But I got nothing more. Definitely keen to get my ride back, but from some internet searching it does appear to be an issue affecting mk4 and mk5 TDI engines whereby the vanes or the actuators get stuck - mostly due to not being given a good flogging every now and then like a good diesel deserves.

[Greg Roles]

My vote is sticking vanes, they won't throw an error, but would do as described. Also I had terrible over boost issues when the turbo actuator bleed line, running from the vacuum solenoid on the turbo to the inlet just after the air box was clogged. This line has to be free to allow the vanes to operate correctly. My vote is a tank of premium, some cleaner or soot reducer such as the Morleys stuff, and a good flogging getting the turbo hot, and working the vanes through their range hard. You want to do so with minimal soot, which causes them to get sticky in the first place, hence the additive.

[Dyldo]

thanks cogdoc. She is already with VW. Well, actually, she's with a multi-service shop that does VW and GM and Toyota and god knows how many other marquees. Think those guys can work it out?

[ForceFed]

Thanks Greg. I will suggest that to the guys at VW tomorrow.

[ForceFed]

So I got it back from VW. Reset the ecu. Problem still remains. I took onboard Greg's suggestion of giving it a flog, no luck unfortunately. I have run the car on BP Ultimate Diesel since i bought it (only my second tank).

It feels as if it is stuck in low boost. Under normal driving conditions if you try to feed it some burst turbo makes a squealing noise and barely spools.

Do you think the vanes are stuck or is this baby toast??

Again, what a start to owning my first dub.

[Transporter]

So I got it back from VW. Reset the ecu. Problem still remains. I took onboard Greg's suggestion of giving it a flog, no luck unfortunately. I have run the car on BP Ultimate Diesel since i bought it (only my second tank).

It feels as if it is stuck in low boost. Under normal driving conditions if you try to feed it some burst turbo makes a squealing noise and barely spools.

Do you think the vanes are stuck or is this baby toast??

Again, what a start to owning my first dub.

Did they have any suggestion what would follow next?

[ForceFed]

Am going back today to discuss it.

[Greg Roles]

The noise worries me. Apart from an obvious boost leak, it seems like the VNT system has a problem. As the vanes are controlled by air pressure solenoids, might be worth investigating. If problem remains we can put up some DIY pics of parts to check, but I am working a conference till Sunday arvo so wont be much help till then. Only drama is the 103 has the turbo down low, hard to access / see...

[ForceFed]

Thanks Greg that would be great. It's booked in tomorrow at Ford (of all places) under the used car warranty. They are going to say nothing is wrong with it as I'd expect.
I'll get them to look for vacuum/boost leaks.
VW suggested to do a full boost pressure test that can only be done using their VAS system.

They drove the car under normal low boost conditions and said it drove ok but I insisted that anything above low boost is the issue. It feels as if the engine is doing all the work if you give it a bit of stick.

I will keep you all updated. Have to get to the bottom of this.

[Dyldo]

We've got two TDIs on issue here. The VW guys have mine and have been trying to get it to throw the error codes but so far today they have't had it overboost and show the issues (ie limp mode). I'm happy they're being thorough, but as always keen to get the ride back (for my wife).
I tried to nicely tell them to look at boost issues and sticking vanes/actuators but got crickets.

[ForceFed]

Well just as I suspected the Ford guys found nothing with their "Universal" diagnostic software. I suggested sticking vanes/actuators and they looked at me dumbfounded. I explained that yes some boost is coming through the turbo but not as much as it should be. Low boost = OK Any more boost = SHIITE

They recommended that I go see "their" preferred repairer and I said that's all well and good but wouldn't you think a VW specialist will be better equipped to diagnose this type of problem?

I guess I need to go back to VW and get this boost pressure test and then go back to the yard i bought it from with the results.

What a headache....