R5 touareg 2005, overboost

barny1togo · Jan 17, 2023

Simply when pulling hard or quick responce excelaration ( not always ) 75% of time, engine goes into limp , i say 50% as car will run slowly up to 50mph.
Stop, off then re start, clears, shows over boost on scanner, clears ok, very annoying.
Turbo and solenoid seem to work ok, kickdown is sloppy and slow in reaction.
Performance is very unpredictable in you can never tell how reactive/responsive /power it is going to be on the day.

NO error faults.

SaVAGeSoot · Jan 17, 2023

How does it show "overboost" on scanner, but there are not faults?
ECUs don't go into limp mode without throwing codes.
Please posts said codes or results from said scanner.

barny1togo · Jan 17, 2023

The fault simply displayed overboost, it was a snapon scanner , true it cleared from memory easily.

SaVAGeSoot · Jan 17, 2023

Check your piping and connections. Without any more data, I'm calling it a boost leak.

Flash635 · Jan 18, 2023

Did you check the turbo nozzles for sticking?

When this used to happen to my R5 I got a code that said the actuating solenoid was faulty but it wasn't.
It turned out to be the water pump leaking into the crankcase. That's an engine out job.

barny1togo · Jan 18, 2023

From the driving situation I concour it could be, will investigate, perhaps hook up a boost guage and run it inside for active response.

Flash635 · Jan 18, 2023

Just watch the VNT vacuum actuator while someone blips the throttle.
You should see it move.

Check under the oil cap for moisture and sludge.

SaVAGeSoot · Jan 18, 2023

There aren't "that many" connections to check.
For something that old, the first thing I'd suspect would be the turbo outlet connection... the o-ring on that hose.

SaVAGeSoot · Jan 18, 2023

Visual

Flash635 · Jan 23, 2023

SaVAGeSoot said:
Visual

You'd easily hear it if it were losing enough boost to make that much of a performance difference.
Not saying that's it though. Losing boost doesn't trigger a code.

SaVAGeSoot · Jan 23, 2023

Flash635 said:
Losing boost doesn't trigger a code.

Based on what?

Flash635 · Jan 23, 2023

Are you asking me how I know?

SaVAGeSoot · Jan 23, 2023

Flash635 · Jan 23, 2023

I've got one, remember?
No code even when the charge pipe blew off completely.

wozzlegummich · Apr 10, 2023

Flash635 said:
It turned out to be the water pump leaking into the crankcase. That's an engine out job.

Wow, If you paid someone to take your engine out just to replace the water pump I'd be asking for a refund! Sure, it's a bit of a bugger working down there at the rear of the motor, but it can be done and with no cutting or poor practices.

Flash635 · Apr 16, 2023

It was under warranty.

Flash635 · Apr 17, 2023

wozzlegummich said:
Wow, If you paid someone to take your engine out just to replace the water pump I'd be asking for a refund! Sure, it's a bit of a bugger working down there at the rear of the motor, but it can be done and with no cutting or poor practices.

You know I was talking an R5 don't you ?

volkswagens-for-life · Apr 24, 2023

Flash635 said:
You'd easily hear it if it were losing enough boost to make that much of a performance difference.
Not saying that's it though. Losing boost doesn't trigger a code.

Yes it should. Actual won't meet requested. Absolutely should trigger cel. Of course, quirky Volkswagen.. 'nuff said.

OP - overboost can be from boost leaks (think charge piping) or can be bad turbos

Flash635 · May 9, 2023

volkswagens-for-life said:
Yes it should. Actual won't meet requested. Absolutely should trigger cel. Of course, quirky Volkswagen.. 'nuff said.

My charge pipe blew off completely, no code.

volkswagens-for-life · May 9, 2023

Flash635 said:
My charge pipe blew off completely, no code.

I believe you. It's SUPPOSED to, but like I said.. quirky Volkswagen things...

R5 touareg 2005, overboost

barny1togo

SaVAGeSoot

barny1togo

SaVAGeSoot

Flash635

barny1togo

Flash635

SaVAGeSoot

SaVAGeSoot

Flash635

SaVAGeSoot

Flash635

SaVAGeSoot

Flash635

wozzlegummich

Flash635

Flash635

volkswagens-for-life

Flash635

volkswagens-for-life

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