Weird problem, mil light on 3.0

[firebobby]

The other day when coming home towing my caravan, the EML came on and there was a slight loss of power to the engine, I pulled over and turned the engine off. When restarted, it ran perfect and I joined the motorway again for about 20 miles, then it happened again a few more times. This time I turned the ignition off and restarted it on the move and it ran perfect again, when it happened, there was no smoke or anything like that, just a slight loss of power.
I'm not sure what is happening, I fitted a new fuel filter a few weeks ago and that made a huge difference to the performance as it was doing the same thing before the filter change. Is it possible that the new filter has clogged up again :nenau

Help

 

[R1cho]

yep sounds like the fuel filter, happened to me i went through every thing to fix it, new maf the lot, then it turned out to be a £10 filter i was not happy :lol

 

[Trenches and Tracks]

It could be the filter, but if it was I would assume that there would be a constant loss of power.
It could also be the ecu putting it into limp mode when the turbo boost has spiked., due to the additional load of the caravan
If it happens again immediately come off the gas, let the revs drop to around 1000 and then pick it up again. If the power comes back as normal then its the ecu dropping the pressure in the system. There is a pressure gauge in the intercooler. If the power does come back you can continue, but the light will stay on until the ignition is switched off.

 

[firebobby]

yep sounds like the fuel filter, happened to me i went through every thing to fix it, new maf the lot, then it turned out to be a £10 filter i was not happy :lol

I will get another filter, just to see.
It's strange because on the way up to Birmingham, she pulled like a train, no hint of hesitation, then on the way home it did it about 3 times.

 

[firebobby]

It could be the filter, but if it was I would assume that there would be a constant loss of power.
It could also be the ecu putting it into limp mode when the turbo boost has spiked., due to the additional load of the caravan
If it happens again immediately come off the gas, let the revs drop to around 1000 and then pick it up again. If the power comes back as normal then its the ecu dropping the pressure in the system. There is a pressure gauge in the inter cooler. If the power does come back you can continue, but the light will stay on until the ignition is switched off.

The strange thing is, it was doing this before but once I changed the filter...perfection, in the years I have owned her, we have towed many thousands of miles with out a single issue. I wonder if there was some crud in the tank.
I will stop putting 2T oil in with the fuel as it may have something to do with that :nenau

I will try your throttle method if it does it again though

 

[Barrbeast]

It could be the filter, but if it was I would assume that there would be a constant loss of power.
It could also be the ecu putting it into limp mode when the turbo boost has spiked., due to the additional load of the caravan
If it happens again immediately come off the gas, let the revs drop to around 1000 and then pick it up again. If the power comes back as normal then its the ecu dropping the pressure in the system. There is a pressure gauge in the intercooler. If the power does come back you can continue, but the light will stay on until the ignition is switched off.

Except EML shouldn't come on if it is just the overboost protection, far as I know (never heard the Aussie's mention the light going on) :nenau

 

[rustic]

I wouldn't have thought the two stoke oil would cause this problem.
Are you using mineral low ash, two stroke oil, in a ratio of 200:1 diesel to 2T oil?

 

[firebobby]

I'm using mineral 2T oil at about that rate, I'm just looking at what I have done different since this started and using 2T oil is the only thing, could it be cleaning gunk from the tank :nenau:nenau

I will change the filter again to see if it stops this, if so, I may stop using the 2T.

 

[Thomas-the-Terrano2]

on my zd trol, would get this, overboost and check light, then loss of power.

didnt always switch off n restart, just eased off then business as usual.

 

[micktheshed]

I'm using mineral 2T oil at about that rate, I'm just looking at what I have done different since this started and using 2T oil is the only thing, could it be cleaning gunk from the tank :nenau:nenau

I will change the filter again to see if it stops this, if so, I may stop using the 2T.

I have same engine & have used 2SO for 18mths or more. No probs. (as yet LOL), but agree it may be gunk freed from tank by 2SO. In which case change of fuel filter should show improvement, at least until remaining gunk has worked it's way through again! Couled also be duff fuel so try somewhere else for the next couple of tanksful.
I always carry a spare filter just in case.............

 

[Barrbeast]

Yeh I've been using 2T in my diesel for a long time now and have never had any filter issues (feverishly touches wood) so I wouldn't blame the 2T direct unless it has maybe shifted some gunk as micktheshed suggests. Duff fuel is always a possibility too, particularly if you use supermarket fuel.

on my zd trol, would get this, overboost and check light, then loss of power.

didnt always switch off n restart, just eased off then business as usual.

Didn't realise the check light would go on but helpful to know given I've now blanked off the EGR valve!

Firebobby just in case it is the overboost protection kicking in then it would be worth checking and cleaning the throttle body (Glowplug Replacement pdf).

If it is overboosting and you can't find what's causing it then you could adjust the VNT stop screw (EGR Blank pdf) to stop it. If you're doing that anyway though then you might as well fit an EGR blanking plat at the same time :thumb2

 

[perelaar]

I've had similar problems a few years ago, driving a brand new Seat Leon 1.9TDI. Only after taking fuel from one specific brand. Filling it up with diesel from another brand solved the issue... In that case garage confirmed that specific brand had some additives in the diesel causing sensor issues in the Seat...

 

[AlexD333]

Yes it is meant to clean up :thumb2

 

[firebobby]

on my zd trol, would get this, overboost and check light, then loss of power.

didnt always switch off n restart, just eased off then business as usual.

What did you do to solve it then or did it go away :nenau

Thanks everyone for the suggestions, I buy my diesel from BP, so would like to think they sell good fuel, but you never know.
I had a quick look in the throttle body and there was a small amount of gunk in there.

 

[firebobby]

I fitted another new filter today but haven't tried it yet because I am in the middle of fitting poly bushes to my ARB's.
The front is done, what a bloody job that was though as the new poly bush doesn't have a split like the rubber ones so I had to thread it along the ARB :doh
All fitted now though, just the rear to do and then I can test it out.

 

[panelbeater]

to all,why do you not fit a large clear pre-filter to it just befor the main filter to catch any crap that is getting through.all thats needed is 6" extra fuel pipe a double size clear filter and clips to secure and you can see if anything is getting to main filter.they are about £2 from fleebay if you get 5 a time.my main filters last a year on my wvo mix.

 

[firebobby]

to all,why do you not fit a large clear pre-filter to it just befor the main filter to catch any crap that is getting through.all thats needed is 6" extra fuel pipe a double size clear filter and clips to secure and you can see if anything is getting to main filter.they are about £2 from fleebay if you get 5 a time.my main filters last a year on my wvo mix.

Good idea, what size filter/pipe do you use