PD170 with no power 1800rpm-2300rpm

[c_w]

I have a 2007 2.0 PD170. I've had the car for about 10yrs and it's been on the whole very reliable and also well looked after/serviced. However I have an issue that came on suddenly that I can't figure out; there is no power from around 1800rpm to around 2300rpm, after which where it starts to pick up and run kind of normally (maybe at around 80% power). Below 1800rpm it drives normally, perhaps a little down on normal power.

From 1800rpm I can have my foot flat to the floor and it does nothing at all, just stays at the same revs, except in 1st and 2nd gear where I can get it to "drive through" this deadzone and it starts to pick up. On VCDS it shows around 90nm torque (actual), even though with foot to floor driver request is 430nm.

Say in 3rd going up a hill, at 2000rpm it starts to judder and slow down. If I drop down in to 2nd to ensure revs around 2500rpm it will accelerate.

It idles perfectly smoothly, mpg is normal (ie great), there are no unusual noises.

VCDS show a very non-specific fault code:

============
1 Fault Found:
000000 - SAE - Reserved by Document ISO 15031-6
P0000 - 006 - 2005
Freeze frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 395227km
Time Indication: 0
Date: 2021.01.22
Time: 16:02:46
============

I read a thread a while back about a 170 with similar issue but can't find it!

 

[aqibi2000]

I have a 2007 2.0 PD170. I've had the car for about 10yrs and it's been on the whole very reliable and also well looked after/serviced. However I have an issue that came on suddenly that I can't figure out; there is no power from around 1800rpm to around 2300rpm, after which where it starts to pick up and run kind of normally (maybe at around 80% power). Below 1800rpm it drives normally, perhaps a little down on normal power.

From 1800rpm I can have my foot flat to the floor and it does nothing at all, just stays at the same revs, except in 1st and 2nd gear where I can get it to "drive through" this deadzone and it starts to pick up. On VCDS it shows around 90nm torque (actual), even though with foot to floor driver request is 430nm.

Say in 3rd going up a hill, at 2000rpm it starts to judder and slow down. If I drop down in to 2nd to ensure revs around 2500rpm it will accelerate.

It idles perfectly smoothly, mpg is normal (ie great), there are no unusual noises.

VCDS show a very non-specific fault code:

============
1 Fault Found:
000000 - SAE - Reserved by Document ISO 15031-6
P0000 - 006 - 2005
Freeze frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Mileage: 395227km
Time Indication: 0
Date: 2021.01.22
Time: 16:02:46
============

I read a thread a while back about a 170 with similar issue but can't find it!

Fault logged is related to the DPF (is it removed/car remapped)?

 

[c_w]

It hasn't had a DPF (or EGR) since 2015 when it was gutted & remapped. I've done almost 100,000miles in it without issue though; is it possible this could still be related?

 

[c_w]

Just to update this issue. I've managed to find out why it's going in to a limp mode from logging with VCDS; the EGT sensor is registering very high exhaust gas temperatures. DPF sensors are all showing around 250-300c, but the EGT is showing around 650-700c on cruise and flicks to 1000/1024c if I try to accelerate on boost around 2000rpm and knocks the car in to limp mode.

From what I can see EG temps are at their highest when then engine is pulling hard from lower rpm on boost (ie 1800rpm on)?

The car doesn't throw any EGT codes and there's no EML lights on the dash so perhaps the DPF delete map is preventing this (and just throws the generic Reserved Document code).

I believe the sensor is faulty as it will occasionally show 1024c (or 1000c) when the engine is off. It's working of a sort most of the time and the car runs fine until it hits that peak figure, but the general readings are not accurate, so on a stone cold engine it will read 90c (other DPF sensors showing ambient, around 7 degrees).

My next issue is why it's gone faulty as it ties in with another problem I have with the car, and that is white smoke, which could be coolant (hard to tell if it's overfuelling and unburnt diesel). The car is very hard to start first thing but runs well once started, and does loose coolant now and then. I fear the head may be leaking coolant slightly and I have read EGT sensors do not like anti freeze contamination.

 

[desertstorm]

If the Sensor is reporting excessive EGT's incorrectly the ECU will go into protection mode and limit fuel,so effectively a limp mode. If the EGT sensor is randomly reporting 1000 degree temps whilst sitting there then the sensor is faulty. Have you checked the glow plugs?, these may be related to your cold start issue.
If the car has had a generic remap they quite often disable large amounts of fault codes from reporting so this makes it difficult to diagnose issues. The car has done a lot of miles there are likely many parts on the engine past their best. Cracks in the cylinder head are common on these as well. They can occur between the water jacket and exhaust port which results in white smoke from the exhaust.
The part number appears to be
03L 906 088BS

https://7zap.com/en/part/VAG/03L906088BS/

Plenty of cheap no name spurious parts from around £35 on Fleabay. You can get better quality OE spec parts for around £50. A genuine part is likely to be £80-100 . You could try ringing your local VAG dealer parts dept and quote the part number and see what they say. Any Skoda, Audi VW garage would be able to supply this.


https://www.ebay.co.uk/itm/New-Genu...467122?hash=item5da8e3e8f2:g:aJYAAOSwNKledIXc

 

[c_w]

Thanks, I actually ordered a VDO sensor from GSF but a Metzger sensor arrived so should be decent quality. Ive actually left it loose but plugged in under the bonnet and it drives fine now.

I took it to a garage to get it swapped over but they're feeling like the old one is going to snap leading to a much bigger job so didn't go further. I think they were also mindful that if the car does have a head crack/gasket issue it could also damage this sensor too and they reckon the turbo is noisy. Its always been noisy (like a faint siren) when I got it on 93k but its on 246k(!) now.

Probably had my monies worth out of it but it drives so good (once it finally starts!) I don't want to just give up on it. Ive put some steel seal in it mixed with fresh water and this seems to have reduced the idle smoke/steam massively that i've noticed (it never produces anything when driven).

 

[aqibi2000]

I’ve replaced the pre turbo egt for the same issue on my pd170 a couple of years ago, it too would flick to 1000 degree C.

Installed original sensor about £90 via eBay. Had to sit on the engine to access it on the exhaust manifold