Stuck in Limp mode. Hour thrashing it didnt help. Replace dpf sensor? dpf blocked?

[BlueFabiaDieselCr]

Hello all,

Any advice to get out of limp mode and back into a smooth running car again please? I am a diesel newbie. Petrol fabia was amazing for 50k miles and cost just a grand.

 

Only light on ever, was a flashing coil light. Constantly on now. 

 

It's a 2010 1.6 tdi 105hp CAYA cr

80K miles (non emissions fixed) had a faulty injector and replaced it (also got a spare 3 used ones too if needed)

 

Been stuck in limp mode for a few days now.

 

Not sure if I can do a forced regen myself?

 

Looking at getting  the Carista Bluetooth dongle of eBay for the diagnostics monitoring and get an app for the phone.

 

I already did about 25mins thrashing without slowing down 3 times now. An hour really with odd interruption.  Maybe needs a longer hard thrash at 2.5k revs at 50mph. very rural here no motorways for an hour. But could be good to blast it for hours. Don't know if there's a danger of overheating anything though.

 

I am moving house this week so that takes priority, to pack and get moved out this weekend.

 

I read it can't do an active regen if there is some kind of fault code showing.

 

Does it needs a vag com diagnostics forced regen?

 

Can i reset the faults with the Carista diagnostics dongle and then the dpf could do an active regen?

 

Garage said foot to the floor at 2.5k at 50mph should sort it, after a 5min diagnostic. All I could see was a dpf sensor fault and maf fault iirc.

 

Thank you all for any pointers!

 

 

Edited 27 January, 2019 by BlueFabiaDieselCr
Clarity

[2ndskoda]

There are so many tdi's with limp problems. First move is to get an analyiser full check out done.

[amwphotos]

If they are sensor faults then you need to fix those before worrying about whether it is doing a regen surely. "Thrashing it" just creates more soot.

[MarkTB]

Could also be EGR as that presents with coil light and limp mode too, as above, get it scanned to confirm.

[mrgf]

EGR's can often be a pain but also, can often be removed, cleaned sufficiently and re-fitted. Most dealers would rather fit a new one as its simpler, makes more profit and has less chance of a reoccurrence but we do live in a disposable age!

 

[BlueFabiaDieselCr]

Thanks for the pointers everyone.

Much appreciated!

 

Moving this weekend and will be free then to book it in next week.

 

Is a dealer the way to go (about 25miles away on small rural roads or can a smaller local (and cheaper) garage do an egr I wonder?  

 

A local garage could prob give me a quote and let me know if they can do it after looking at the diagnostic report.

 

So could be blocked egr or dpf, faulty dpf sensor or miscellaneous I guess.

 

Still got to do about another 100miles for work.

 

Will let you know how it goes,

cheers again.

 

[2ndskoda]

Do you have a VW independent specialist garage in your area? Try google / yellow pages.

[delta925]

A VAG independent specialist or a multi-brand independent with the full VCDS system ought to charge much less for a diagnostic scan, maybe even free for good reputation and word-of-mouth publicity.

 

You say the coil light not the DPF light is on. If EGR or a sensor has failed no amount of driving will clear the fault.

 

It the requirement for a DPF regen that can be initiated with driving but the car should not be in limp mode.

 

 

[delta925]

On 01/02/2019 at 11:11, mrgf said:

EGR's can often be a pain but also, can often be removed, cleaned sufficiently and re-fitted. Most dealers would rather fit a new one as its simpler, makes more profit and has less chance of a reoccurrence but we do live in a disposable age!

 

 

True the EGR could be cleaned then may work again but given the time to remove parts so that EGR can be removed, remove the EGR, then reassemble is 5-6 hours it a lot of work if the fault remains or soon reoccurs. One reason for failure is the position sensor which is caused by an internal seal failing. An indication of this possibility is slight coolant loss.

 

The 1.9PD TDi EGR was readily accessible and a new part cost much less.

[BlueFabiaDieselCr]

Many thanks for the replies.

 

I have never seen the dpf light in just the cool used to flash sometimes then replaced injector and then very rarely.

But now the glow plug coil light is constantly flashing. 

 

So it seems that it could be the egr valve.

I only saw MAF and dpf sensor come up with the free 5min diagnostic at another local garage.

 

 

 

So what about just blanking it off and have a remap? Legal? expensive?

 

as the exhaust will be hotter and the dpf will work better?

 

 

There is a remapping expert and also another Garage is VAG specialist in Pembrokeshire where I am.

 

The egr valve part seems about £240 approx. Maybe clean it is an option.

 So 5hours labour on top is £150 around here.

 

The dealers seem to charge as much as poss reading on the forums. 

A keen local garage would be better, i will ask about the VAG specialist. And check with my usual honest garage if they have done an egr. Seems a hard location to get to the egr.

Will look at coolant level, re

the position sensor and internal seal failure. 

I am in mid house move and can book it in with my friendly local for a scan and then go after a few quotes with the car work enquiries.

 

Cheers for all your opinions it's very valuable to get specilaised advice

[mrgf]

Dunno about your EGR valve but mine is on the rear of the engine and fiddly but not difficult for a trained mechanic! I would guess a couple of hours max, to remove and clean and refit or replace if clearly flucked. 

A delete will be about the same labour, the part should be much cheaper then the actual real valve as its a basic plate but it may be illegal. This will only be an issue, if discovered, though! It MIGHT have been done prior to you buying the car, so you would not even know it was (N't) There! 

If any additional work needed was done to, ensure the delete was proper in function, I don't suppose it will be spotted or offer any other problem. 

Edited 5 February, 2019 by mrgf

[Shim]

I have just replaced the EGR on my 2010 Fabia 1.6TDI. Exactly the same symptoms as the OP, in limp mode.

So here's the short story;

 

P0407 code

 

Genuine but re-conditioned VAG EGR to my door £168. 2 year warranty with upgraded circuit board.

 

Car up on ramps then remove wheels & get as high as possible but not too high so reaching inside the rear of the engine becomes a balancing act. I have a hop-up for this which gives me a 200mm advantage.

Vehicle supported on axle stands & mining timber for extra safety. Plenty of lights! Nice piece of carpet on the floor for comfort.

Remove belly-plate by undoing the x9 torx screws. Un-couple centre section clamp on the exhaust, disconnect track rods, undo steering rack (x4 bolts) undo subframe bolts. Disconnect pipework & LAMBDA sensors, exhaust rubbers & remove the DPF unit from the turbo having undone the clamp & the angled support bracket from the engine block. This procedure is not so easy but with care you can push the subframe forward to twist & remove this piece of the exhaust. It has this lump on one end & has to fit through a small gap!

Then drain the coolant from the feed pipes to the EGR unit. Removing the air flow pipes helped here. Check with a torch for wiring joiners & their routes as they are not happy being pulled. Photo these if you are unsure if you can remember later. They are mostly pretty obvious though.

Remove the two little by-pass exhaust sections along with the turbo return pipe. The one that goes up to the cylinder head is very fiddly, many cuts.... Removing the air filter & associated pipework helps. You can lubricate the gear selector linkage at this moment.

The oil feed pipe to the turbo can be disconnected from the feed end & moved out of the way, leaving it still connected at the turbo (remember x2 new copper 'O' rings later. £0.48p from the local ag store).

Disconnect the water pipes & undo the X4 Torx bolts that hold the EGR to the engine block & any others that need removing that I've forgotten about. The two studs in the block can also be removed & I believe these are designed to do just this to make life a little easier.

Remove EGR in a similar fashion to the DPF by a twist & ease.

Re-fit all in reverse to above. Not forgetting to re-fit the little heat jacket to the EGR vacuum unit (two poppers)

Re-fill with coolant.

I used ebay for the SS gaskets. I needed x1 for the small pipes as there are x2 in the box & x1 turbo to exhaust gasket from the same supplier.

Now I zeroed the electronics using an Autel MD 808pro scanner & ran the engine up to temperature for an hour or so, not forgetting to keep an eye on the coolant in its round nylon reservoir.

Took vehicle for a test run, I'm going on a 100 miler soon just to make sure all's well, no more limp mode. Yaaaay!

That's it. Now I'd be pushed to do this in five hours but perhaps with a nice two post ramp the job may be a little easier.

You'll need 1/4 drive Torx & associated bars & ratchet. 3/8 similar with a nice breaker bar. The odd 1/2 drive. A 27mm (1 1/16") combi spanner or socket for the oil return pipe.

A good selection of metric sockets in 1/4 & 3/8 drive. Similar combi spanners from 12mm through to 27mm.

Plenty of good clean rags.

 

Shim

 

[m8t]

It needs a diagnosis plugging in to find the fault. Skoda dealer will have the latest software but will charge £60ish just to diagnose. I had 3 of these on my old 1.6tdi. They were O2 sensor. exhaust gas temp sensor and the failed egr. Dealer said the egr would have been £600 if not done under warranty as it needed 5 hours labour.

 

Chopped mine in for the ever reliable 1.9tdi.

[kwakbiker]

Seems my 1.6tdi 2015 rapid is suffering similar fate, dpf light came, before could take for a thrash now have flashing coil light and EML showing, plugged in my obd2 reader, code 258 which is egr  I think, guess this go in to be expensive even at trusted local garage...Grrr, dpf been a pain since having the emissions warranty work done, should of told them to poke it