Turbo Cutting In/Out Tdi 150

[adam skelding]

Hi,
Just wondered if anyone else has had this problem:

Sometimes whilst I'm driving around off turbo ~ 2,000rpm, I go to accelerate and the turbo cuts out. Always at the same point ~ 2100 rpm. The problem seems to be more apparent when I'm in sixth so I assume it's to do with the amount of load on the engine.

If I keep the engine above 2200, it never cuts out.

When the turbo cuts out the engine management light doesn't come on.

I took it into Seat Derby, where they suggested an N75 valve replacement. £120 later and the exact same problem is still there.

Any help would most appreciated.

 

[glynnd]

You need to check all the vacuum lines for a leak. I presume the misdiagnosis means there were no fault codes in the ecu?
Has it been mapped at all? as this cut out can occur when the engine reaches the torque limiter. If not then you could try a map sensor they are around £30 easy to fit and located in the boost carrier pipe at the front of the engine.
Glynn

 

[AndyHazza]

As above, check all pipework if possible. Could be map sensor, could be MAF sensor too. Does it happen only when the car is cold or hot? or does it make no difference?

 

[adam skelding]

Hi,
Thanks for that.

It has been re-mapped, but I've never had any trouble in the 3 years it's been mapped.

Fault seems to occur when it's hot or cold..... It's mainly when I've been 'off boost' in a high gear and then I put my foot down.

An engine management light does come on, but independently of the fault.

I'm dropping the car back in to Seat on Friday to see if they can shed any light on the situation, although they seem to be hell bent on reaming me out for a new Turbo.
When the turbo does kick in, it's fine. All the power is there...

 

[adam skelding]

Still no luck from SEAT on this one....

They are completely baffled.

They showed me the dealer price for a new turbo.... Felt like someone took out my beating heart and showed it to me....



Anyone any ideas on replacements/exchanges?

thanks

 

[glynnd]

Whats the fault code then Adam
Turbo technics for a new turbo circa £500 exchange plus vat
I dont think its a turbo problem though
Does it do it all the time and can you make it do it deliberately
Glynn

 

[adam skelding]

Whats the fault code then Adam
Turbo technics for a new turbo circa £500 exchange plus vat
I dont think its a turbo problem though
Does it do it all the time and can you make it do it deliberately
Glynn

Not sure what the fault code is. Seat haven't given me the info...
It's something to do with the boost regulation apparently.

It is gradually getting worse, the amount of times I have to stop and turn the engine on and off in a morning is increasing...

The Turbo also seems to be coming in later.. Around 2.5-3K rather than before when it used to start spooling up around the 1750 - 2K..

 

[sssstew]

agreed, i would get vag com and check what faults logged. im still thinking boost leak. but then could be sticky vanes on the off chance.... which can be cleaned cheap.

 

[glynnd]

Sounds like its overboosting then due to the vanes sticking as ssstew mentioned
Glynn

 

[Husbandofstinky]

second opinion at least me thinks - as above.

 

[muddyboots]

Sounds like either the vanes are sticking causing the boost pressure to not behave as the ECU is expecting, OR the MAP sensor is failing and misreporting the boost level, leading the ECU to the same conclusion...

One of those times when vag-com would be invaluable.

 

[mik]

As mentioned by Muddyboots - VNT mechanism sticking?

See it in action HERE. I think the TDI150 uses a larger (VNT17?) version.

Also worth reading post #12 on THIS THREAD

 

[glynnd]

The only thing is thought I would have thought it would happen at other points in the rev range not specifically at 2100 rpm if you could say its sticking vanes
Glynn

 

[markandcath]

An interesting point on the sticking vanes issue is it seems to be caused by carbon build up. There are some new products like 10K boost and Power Boost that are injected into the intake manifold that claim to break up these deposits.

I have no idea if they work but as I have sticking vanes on mine I intend to try them before I strip the turbo off, has anybody tried any of them or have any info/thoughts on them?

 

[FR Damo]

A mate of mine had a similar problem with is 130bhp golf, it was a MAF sensor in the end

 

[glynnd]

DO NOT UNDER ANY CIRCUMSTANCES SPRAY THAT STUFF INTO A PD DIESEL INTAKE SYSTEM YOU ARE ASKING FOR BIG TROUBLE IF YOU DO.
They only way to properly rectify sticky vanes is to dismantle and clean the turbo properly.
Glynn

 

[adam skelding]

Thanks for the upshot on the cleaner stuff.

Is the Turbo easy to get at?
I've just got a copy of the full workshop manual 'Elsawin'.
I've not looked at it yet, but I was wondering on the level of difficulty. I'm pretty handy with the tools.

As my turbo has done 90K. I'm going for the sticky vanes thing first. I'm guessing as it seems to be worse when cold and/or when the engine is under a little load with very little turbo operation / acceleration.

Anymore info would be appreciated. D-Day for the turbo is Saturday.
I've seen the link on the guy cleaning his turbo, it looks pretty straightforward. But then again most things do.

Thanks once again guys for your time...

Shame SEAT still can't be bothered to get back to me to give me the fault code.

BTW. I see people mention getting the MAP sensor from VW, any reason? Or just price...

 

[markandcath]

The MAP sensor sits on the air pipe on the right of the engine bay (next to the battery) and it has a very similar plug to the MAF sensor. It is actually a T-MAP (Tempreture and Manifold Absolute Pressure) and a few people say they have had faults were the TMAP sends false info to the ECU and it flags a overboost that doesn't really exist but it is just a few.

If you go for stripping the turbo it comes off on its own from underneath or with the manifolds from the top. A few pics would be nice and best of luck to you, I know I aint looking forward to mine and I am more than happy doing Rover K engine heads so I am not spanner shy.

Good Luck......

 

[Husbandofstinky]

I am more than happy doing Rover K engine heads so I am not spanner shy.

Good Luck......

You'll never be short of work then!

btw the 216 per signature is the old Honda engine - much better (I had a couple of good 1400 K's before the 1600 - just lucky)

 

[glynnd]

Thanks for the upshot on the cleaner stuff.

Is the Turbo easy to get at?
I've just got a copy of the full workshop manual 'Elsawin'.
I've not looked at it yet, but I was wondering on the level of difficulty. I'm pretty handy with the tools.

As my turbo has done 90K. I'm going for the sticky vanes thing first. I'm guessing as it seems to be worse when cold and/or when the engine is under a little load with very little turbo operation / acceleration.

Anymore info would be appreciated. D-Day for the turbo is Saturday.
I've seen the link on the guy cleaning his turbo, it looks pretty straightforward. But then again most things do.

Thanks once again guys for your time...

Shame SEAT still can't be bothered to get back to me to give me the fault code.

BTW. I see people mention getting the MAP sensor from VW, any reason? Or just price...

My turbo has done 114k now and never had sticking vanes I think it depends on the use as mine is mostly motorway type speeds
Glynn