204 DSG intermittent momentary power loss

[mmi]

I would like to do a dynamic log with temp.

Why temperatures? What temperatures?

Anyways,

IGNition ON

VCDS > Select 01-Engine > Adv. Meas. Values
Tick "Group UDS requests" - by 7 (if available)
Tick the desired parameters, e.g:

IDE00021 Engine RPM​

IDE00196 Engine oil temperature​

IDE04090 Exhaust temperature bank 1​

IDE07710 Charge air cooler output: temp. sensor 1: B1: raw value​

Log - Start

By default the logfile - LOG-01-....CSV will be in folder C:\Ross-Tech\VCDS\Logs

 

[nazarko1984]

Why temperatures? What temperatures?

Anyways,

IGNition ON

VCDS > Select 01-Engine > Adv. Meas. Values
Tick "Group UDS requests" - by 7 (if available)
Tick the desired parameters, e.g:

IDE00021 Engine RPM​

IDE00196 Engine oil temperature​

IDE04090 Exhaust temperature bank 1​

IDE07710 Charge air cooler output: temp. sensor 1: B1: raw value​

Log - Start

By default the logfile - LOG-01-....CSV will be in folder C:\Ross-Tech\VCDS\Logs

Hi @mmi ,

I have a MAP 204->232KM and 500Nm. Possible engine reach to high temp and cutting off the power.
I want to log if this is an issue or somewhere else.

 

[mmi]

when I reach about 3200-3400rpm I have momentary power loss. It's kind of wobbling.

Which gear? At full throttle? Does it happen always at that rev range?
Is the momentary just momentary, or does it last several seconds?

Possible engine reach to high temp and cutting off the power.

Any movement on dash temperature gauge?

 

[nazarko1984]

It is momentary when is „gas to the floor”.
Yesterday even when I was on 4th gear was the same issue - momentary loss of power.

At that time I had OBDeleven connected and I checked temp before cat. There was 800C. When this wobbling start, temp. Was changing 800-830, 800-830. So possible here is the issue. I’m reaching to high temp. And power is getting cut by the limit.

 

[mmi]

OBDeleven

Which "Units" you have selected in OBDeleven - metric or Imperial - as the latter shows temperature in Fahrenheit?

 

[nazarko1984]

It is in Celsius. I think in OBDeleven it is standard to have metric.

 

[mmi]

temp before cat. There was 800C

Was the engine doing DPF regeneration? I'd like say it probably was - only then the temperature at catalyst inlet (=turbo outlet) can get high eventually - but still 800 °C sounds dangerously high (above pure aluminium melting point) as the temperature entering the turbo is even higher.

(A) Observed exhaust temperatures at full blast (engine normal run)​

I can't get even 450 °C at catalyst inlet (=turbo outlet). See below two 20 second pulls - pedal down to the floor. Engine revved from 1600 to 2300 RPM at 7th gear.
Note: the plot over 150 seconds.

---

(B) Observed exhaust temperatures during DPF regen​

By doing DPF regen at fairly good load - by driving 130 km/h = 80+ mph - the temperature a catalyst input (=turbo outlet) gets siginificantly higher (peaked at 630 °C while before the turbo a maximum of 710 °C was seen.
Note: the plot across 3600 seconds (1 hour)

---

(C) Observed exhaust temperatures at full blast during DPF regen​

A plot at similar conditions as in (A) - though the pull was done only once. A kind of interestingly the exhaust gases at catalyst inlet (=turbo outlet) actually cools down a bit - presumably by the huge amount of intake air travelling through turbo.

Note: the plot across 100 seconds. The start/end of the pull can be identified by the curve of fuel instaneous consumption.

---

---

EDIT: High exhaust temperatures were observed also in the post below - on a remapped engine.

NOx sensor and Adblue faults codes

So... with that context, that data is from a van where this system was not optimised yet (old software) Yes, partially true. The old software had a distictive feature during DPF regen which produced fairly high NOx levels. I'm putting together a package with three different engine softwares: 1)...

www.t6forum.com

 

[nazarko1984]

Hi MMI,

I went to the garage who made a remap. This is normal behaviour when you do remap. There is EGT limiter set to 800C. Now they move it to 880C.
What I learned it is still safe to 900C but to be avoid any issues I decided to do not reach that high temp.

Thank you for your inputs.

RG.
Marek

 

[John P]

Hi, could anyone help me locate my crankshaft sensor on my 2015 t6?, been searching for 2 hours around the oil filter but no joy. Starting to feel like I’m blind, thick or both!

 

[mmi]

2015 t6

Please clarify - exactly what engine code - on configuration sticker under dash, or on service booklet?
Something like CAAC, CFCA, CXGB, etc.

 

[John P]

Hi, its CAAA

 

[mmi]

Does this look familiar?




906-000

T6 - CAAC CAAB CAAC CFCA Diesel Engine workshop manual

VW workshop manual for the CAAC CAAB CAAC CFCA Diesel Engine Click the download button above to save this file locally.

www.t6forum.com

 

[John P]

Thank you mmi, I’ve been out to take a look but still can’t locate it, I’ve even tried putting my glasses on too. I’m looking from underneath the engine as another thread suggested, around the oil filter area - is this correct?.

 

[mmi]

around the oil filter area - is this correct?.

Yes, the workshop manual states - beneath oil filter bracket.
Here is another view - item 4.

 

[John P]

Thank you, it’s gone dark now but will resume the search again tomorrow armed with this new info. Thanks again

 

[Cog Head]

Hi all
I've been suffering with power loss at full power / high demand
I can make it do it on command, its even more prevalent in sport mode of going up hill with weight in the van, the longer I let it happen, the worse it gets

Since I'm now towing a caravan it happens quite bit going uphills
I've already changed the crank sensor, no change

I do have VCDS

Can I please have some instructions on how to log codes and what codes need logging?

the engine code is CXEB

 

[Dellmassive]

Hi all
I've been suffering with power loss at full power / high demand
I can make it do it on command, its even more prevalent in sport mode of going up hill with weight in the van, the longer I let it happen, the worse it gets

Since I'm now towing a caravan it happens quite bit going uphills
I've already changed the crank sensor, no change

I do have VCDS

Can I please have some instructions on how to log codes and what codes need logging?

the engine code is CXEB

I'd start with a full scan.

Any codes stored?

Do you get a MIL light on the dash?

 

[Cog Head]

I did a full scan and only got silly faulty come up for tpms, and headlight switch, nothing was on the engine.

I recorded some logs online my way to pick up a aux belt tensioned from TPS, so theres quite of lot of data, and I think 20 times I recorded the drop in power.
it is definitely worse in sport mode and when its been given a kicking, and slow down for traffic then go again, it comes back much faster and more of a power drop off.
The logs are attached for the datapoints requested on page 1

In the meantime, ill be on my back outside shouting at an aux belt tensioner

Also, no engine light

 

[Dellmassive]

So are we thinking a drop in boost pressure or a drop in fuel supply/pressure?

 

[Cog Head]

thats what I'm thinking, its as if it takes a little while to recover from high to full throttle applications
in my mind, if it was a boost leak, it would be constant and get worse as the revs raise, but that isn't the case
its got full service history, and its had plenty of fuel filter changes... or so they say...