2.0TDI (PD140/BKD) Emissions (Smoke) Issue

[martinch]

Hi guys,

 

May parents have a 2005 Octavia 2.0TDI (PD140 BKD engine), which just failed its MOT on the smoke test, with a reading of 0.9 (due to the change in MOT regulation this years, it needs to reach 0.7).  Prior to the MOT, it had been given a 30 mile run up and down the motorway, including a period at 4,000rpm, so it should have been pretty warm and cleared-out.

 

The MOT tester said that he thought there was a slight air leak in the turbo/intercooler system, as there was a very faint whistle coming from the front of the car on throttle-off.  Prior to taking it in for its' test, my parents had noticed that the lower boost pipe running between the turbo and intercooler was making a poor connection and weeping oil a little where it connected to the intercooler - they'd removed the pipe, cleaned and re-seated it, which seemed to stem the weeping, prior to the MOT. Other than that, they couldn't see any obvious splits or holes.

 

Any ideas for anywhere else to look, before it goes to a specialist?

 

Thanks!

[Rustynuts]

Are you sure on the level of smoke which has been applied to test the vehicle? According to the new MOT data the 0.7 value is for vehicles first used on or after 1st January 2014. As yours is apparently a 2005 vehicle then it should be tested to the level of a vehicle first used before July 2008.

 

2. New default limit for newer vehicles

You must test to these default values if there’s no emission value on the manufacturer’s plate or you can’t find it.

Vehicle first used	Type	Value
1. First used before July 2008	Non-turbo	2.5m-1 or plate value if lower
	Turbo	3.0m-1 or plate value if lower
2. First used on or after 1 July 2008	All diesels	1.5m-1 or plate value if lower
3. First used on or after 1 January 2014	All diesels	0.7m-1 or plate value if lower

[martinch]

1 minute ago, Rustynuts said:

Are you sure on the level of smoke which has been applied to test the vehicle? According to the new MOT data the 0.7 value is for vehicles first used on or after 1st January 2014.

This was my first thought, as all of the guidance on gov.uk states that the changes apply to DPF-equipped vehicles (which this one isn't).  Unfortunately, the actual tester's manual* doesn't include this restriction.  This means that as Skoda stamped 0.7 on the plate in the vehicle, that's what it's got to conform to, not 3.0.  Apparently it's catching a lot of people out.

 

* To save a bit of reading, this is the actual text from 8.2.2.2:

For vehicles first used before 1 July 2008, the limit will be one of the following:

- the level specified on the manufacturer's plate
- 2.5m-1 for a non-turbocharged engine – if it's not stated on the manufacturer's plate
- 3.0m-1 for a turbocharged engine – if it's not stated on the manufacturer's plate

 

[Rustynuts]

Do you have a photo of the plate showing the data? Or has it been removed somehow?

[martinch]

I'm afraid I don't have a photo (lack of smart phone ...), but the sticker, which is located at the base of the passenger's-side B pillar does indeed say "0,7" (which is what the test station's computer says).

 

The one on my Fabia (in the engine bay, on the inside of the passenger's-side wing) says "0,6" ...

 

I don't doubt the MOT tester, as it's a local council station.

Edited 12 July, 2018 by martinch

[Rustynuts]

It'd be unfortunate if the plate was illegible when it went for a test. But other than that I'd be adding some cetane booster to the fuel for the next smoke test.

[martinch]

5 minutes ago, Rustynuts said:

It'd be unfortunate if the plate was illegible when it went for a test.

They don't bother looking for the plate - everything is on an electronic database, and the computer tells them what it should be 

 

7 minutes ago, Rustynuts said:

But other than that I'd be adding some cetane booster to the fuel for the next smoke test.

There's already some Forte in it (which I assume is a cetane booster?).

[Rustynuts]

The test manual clearly states the data should be read from the plate on the car, and if it's not legible (or they can't find it) then they must test to the default levels in the test manual. Taking vehicle data from an electronic database is not part of the test procedure I'm afraid.

 

Forte is a trade name for various products. I don't know which Forte product has been used.

[martinch]

7 minutes ago, Rustynuts said:

The test manual clearly states the data should be read from the plate on the car, and if it's not legible (or they can't find it) then they must test to the default levels in the test manual. Taking vehicle data from an electronic database is not part of the test procedure I'm afraid.

Literal reading of the instructions - gotcha.

 

7 minutes ago, Rustynuts said:

Forte is a trade name for various products. I don't know which Forte product has been used.

 

Doh.  It'd be the "Advanced Formula Diesel Treatment", which claims to reduce soot emissions (which, now that I look at it, isn't a cetane booster)

Edited 12 July, 2018 by martinch

[Rustynuts]

Look here, maybe.

[martinch]

Thanks

 

Also, any ideas where else to look for an air leak?  The MOT tester was pretty sure the slight whistle on overrun/throttle-off was due to an air leak, which probably wasn't helping things.

Edited 12 July, 2018 by martinch

[Rustynuts]

That bottom hose is notorious for blowing off. The oil leak is only an indication that there's a little oil in the system finding its way out, but if they've cleaned the oil off then it could well still be blowing there.

[martinch]

 

1 hour ago, Rustynuts said:

That bottom hose is notorious for blowing off.

Yeah, I know the lugs on the lower tube wear down and it jumps off.

 

1 hour ago, Rustynuts said:

The oil leak is only an indication that there's a little oil in the system finding its way out, but if they've cleaned the oil off then it could well still be blowing there.

Indeed, it was a fairly obvious indication of a non-airtight seal there.  The assumption was that no more oil meant after disassembly & cleaning meant the seal was good, although, thinking about it, maybe some more time is needed for the oil to start finding its way out (or it's oil-tight but not air-tight).

 

[seriesdriver]

Hi what state is the air filter in might be worth a check.

[martinch]

The air filter's been in there for about 1,500 miles.  There's some marginal discolouration on it, but that's about it - it's pretty clean.

[chrisund123]

Take the air filter out entirely, and put it back in after the test?