MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Tonx on January 19, 2020, 09:18:19 pm

Title: MOT Emissions fail 1.9tdi
Post by: Tonx on January 19, 2020, 09:18:19 pm
So, never had an issue before.

MOT today, readings of 1.99 - 1.52, apparently the maximum reading for this car is 1.0.

Got Halford’s to put their diesel system cleaner in, drove it home circ 4K in all gears and changed the air filter (which wasn’t really that dirty).

It’s in for a re-test in four days time, hoping that 3 x 52 mile  motorway trips to work in a high gear may do the trick.

The other half does one long motorway trip each week, followed by several 2.5-3.5m journeys to work whilst away. Hoping that that is the only cause.

Any obvious things I should be checking or changing to help myself out ?

Dec 2008 1.9tdi Match - 120k
Title: Re: MOT Emissions fail 1.9tdi
Post by: Andy on January 20, 2020, 08:29:59 am
Also change oil and filter and fuel filter put some diesel cleaner through the tank when your fuel is low
We do this at work and they pass
Title: Re: MOT Emissions fail 1.9tdi
Post by: titchy on January 20, 2020, 09:29:48 am
Get some Forte diesel cleaner its what garages use make sure the engine ay normal temp[hot]
Title: Re: MOT Emissions fail 1.9tdi
Post by: Tonx on January 20, 2020, 11:34:15 pm
It’s booked in for an oil / filter tomorrow at NTS and I’ll do the fuel filter Wednesday (already done air filter).

It’s got the Halford’s diesel cleaner in a 1/4 of a tank now, I’ve bought some Wynns Formula Gold (diesel) which I’m told will sort it.

I did notice that it struggles to get up to 90 degrees, even after some 26 miles of hard driving. Normally sits about 70-80 and only got up to 90 after coming off the motorway and queuing.

I’ll run it for the next couple of days hard, then put some V Power in and present it after a hard drive and see what happens.....
Title: Re: MOT Emissions fail 1.9tdi
Post by: Tonx on January 24, 2020, 09:18:54 pm
Quick update:

Presented it for the re-test today with V Power diesel and three days of REALLY hard driving, it passed at 0.93.

I had some Wynns Formula Gold Diesel on standby but it didn’t need it in the end.  I’m going to have to change the thermostat, with normal driving it got to 70 degrees within a few minutes but even on the motorway I struggled to get it to 80 degrees.

Only way I could get it to 90 degrees was motorway driving at nearly 4K in 4th for 5 or so miles. I think I have a lazy thermostat which may not be letting the engine get properly hot.