Hi my mkII 1.9 tdi pd115 is running rough when up to temperature.
It is fine from start up, occaisionally it revs up on starting, with no smoke then after about 5 or 6 miles it starts running badly. It judders almost as if the timing was out and it doesnt clear through, when you turn off the engine and re-start it is fine running smoothly but not for long.
The engine management light is not on so I have no idea what it could be. I thought egr valve or air flow sensor but I thought any faults with these would would make the warning light come on.
It is a 52 plate with 113k on the clock.
Any one got any ideas?
maybe faulty injector wiring, have you checked for fault codes that would be the first step.
Hi Chris, I will plug in reader this morning and let you know. I am guessing the code will come up if the engine is cold.
Intermittent incidences will have been stored from previous events
Code reader has a flat battery, so I will have to wait unti l tomorrow when it is charged. As there is now light showingon the dash it might not register a code any way.
I am thinking it may be mass airflow sensor, I believe this is a common fault on vw engines and is a good and easy place to start.
EML light very VERY rarely triggers on the Tdi.
MAF fault is unlikely to cause the symptoms you have tbh and like Chris, I would look at injector wiring (which is a known fault) and also EGR maybe sticking open (remove and plug the vac pipe to it as a test)
Your right Mark its not the MAF, I took the car out today and true to form it started running rough as soon as I hit the A30. I disconected the MAF whilst the engine was running and it made no difference. So I stopped plugged it back in and restarted and it ran fine into town to the tip, switch off re-start, garage switch off re-start, back home again (9 miles) and it didnt miss a beat.
So as long as the engine is turned off every now and then the system re-boots and it works fine for a while. This, however wont do. My wife needs the car for work and needs it to be reliable. So I will try the code reader, the garage in town wants Ã,£45 to plug in the vw or ford specialist readers and tells me not to bother with a generic one. But Ã,£45 for it to read nothing seems a lot of cash to waste.
I will plug the vacuum pipe tomorrow( is that the rubber hose that goes into the top of the EGR?) and give it a run out. If it behaves fine I take it that I will need to take out the EGR and give it a right old clean out.
Thanks for your help so far.
Yeah thats the correct pipe to plug.
How far are you from me? There are a few members in Devon who I'm sure will read your codes.
I live in bridestowe, near okehampton. Where abouts are you Mark?
Ahh North Devon eh, probably a little too far as I'm Westbury in Wiltshire, maybe a South West meet up in Yeovil is in order? :)
Could be on the cards Mark, if I thought the motor would get there with out major traumas to the engine.
Fault code came back as (drum roll).............
Wiring fault or earth to injector no 1.
I had to clear all previous codes go for another drive and re-plug in. The only code I couldnt shift was intermittant fault on coolant temp sensor.
I will take the wiring out and give it a good clean and see if that helps. So off with the bulk-head extender again!!!!!
Any one no where to get new wiring for injectors? I can get second hand bits up the road but I will be taking a chance.
A coolant temp sensor giving bad values could cause some bad running as the ecu references it to know how to fuel the car.
IIRC the wiring comes as a mini-loom from VW for about Ã,£90 or as usual, there are many knocking about on Ebay:
http://www.ebay.co.uk/itm/Genuine-Audi-PD-injector-wiring-loom-038971600-for-A3-A4-A6-1-9-2-0-TDi-/251622027163?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a95d76f9b
Simple question, how do I get the clips that hold the wires into the injectors off?
I've never removed an injector wiring loom from the cylinder head of a PD engine but I would figure that with the rocker cover removed you are able to access the four individual multiplugs connecting the loom to each injector, with the multiplugs disconnected and tucked out of harm's way you can then slide the loom out of the cylinder head (having disconnected the loom from the external multiplug on the end of the cylinder head, plus removing the retaining bolts, and having either removed or made suitable holes in the battery enclosure trim to make enough space to slide the loom out!).
All done with a bit of prising with a screw driver. Got new loom from VW for Ã,£56. I took the oppertunity to replace the pollen filter whilst I had all that extra room.
So I thought why not clean EGR valve whilst Im about it too. So I bought some Wynns Diesel EGR cleaner.
A word of warning folks. I followed the instructions,(not on the can only available as pdf download) to the letter. Spray into the air intake in 2 second bursts, ok here goes engine is nicley warmed up......
Psssss 1 psssss 2 ..chug chug bang!!!!!! The engine just sh@t itself. It took a couple of seconds cranking and fires up with loud knocking sound. Thats not supposed to happen, and they want me to squirt 200ml of the stuff in here, I dont think so.
The long and the short of it, car now drives for about 3 or 4 minutes then goes into LH mode. So its off to my mate up the road to see if he can re-boot the system.
Trouble is anything you spray into the inlet is going to be injested including all the loose carbon from the EGR and inlet manifold.
Sounds like you now have a boost issue which is causing limp mode, this may have been masked by the injector wiring issue.
Scan the car again you will probably get 17965 which is overboost (most common) or underboost which is 17964
Thanks Chris, I figured it might have something to do with the turbo.
Assuming I get those codes, how do I go about rectifying them. Is this a mechanical issue or to do with ecu?
Overboost will nearly always be clogged turbo vanes, this usually happens if the car does repeatedly short journeys around town without having a blast down the motorway or driving it like you stolen it.
How you deal with it well my advice remove the turbo and the inlet manifold then you can strip the turbo and clean the manifold and EGR valve.
Have a look at the links below.
https://www.fordmpv.com/smf2/ford-galaxy-reference-library/galaxy-mk2-intake-manifold-cleaning/
https://www.fordmpv.com/smf2/ford-galaxy-reference-library/turbo-removal-115-pd-engine/
Underboost may also be down to sticking vanes but is more likely to be a split on a charge pressure hose, leaking intercooler or vacuum leak on the control piping or a faulty control valve (N75 valve)
Nice one Chris, the links look very helpful.
Seeing as this is my wifes car, and she uses it mainly for short journeys, hopefully its the clogged vanes. The car does only about 6k a year and rarely does more than 100 miles in 1 go, maybe 4 or 5 times a year. My wife also sticks rigidly to the speed limit (nothing wrong with that, except I know she thrashes the Sprinters she uses at work).
I will let you guys know how it goes tomorrow afternoon, I shall have the fault codes in a sealed envelope and reveal them after the reading has been taken, thus getting the readings done for free(not much chance of that).
If this one gets sorted using this web site I think I might have to Donate sumthing.
you havnt actually said whether you have given it a 'bloody good thrashing' to clear the crud out?
drive it like you stole it.
Greg cant thrash it because I can only just make it out of the villiage before limp home kicks in.
can you not even manage to rev the nuts off it in 2nd gear?
You could try exercising the actuator rod on the car to see if the lever moves freely or sticking.
In the video below the turbo is off the car.
https://www.youtube.com/watch?v=M-8Kd7oDFTw
What i'm doing with the spanner you need to do with a finger as space is very restricted.
Do this as many times as is possible then try driving the car hard up to 4000rpm preferably going up a incline.
If you do this in six second bursts that is back off throttle then repeat it shouldn't go into limp mode, more than seven seconds it will go into limp mode, if it does you then need to stop switch engine off then restart then the power will return.
If you repeat this long enough you may burn enough crud of the vanes to stop them sticking.
Only do this if the cam belt is in good order and not due changing.
Right folks, the code has come back as a faulty MAF. Hmmmmm. this is goimg to cost about Ã,£80 in about an hour when I go pick it up.
I will try that actuator wiggle and the revving, it cant do any harm, the engine sounds sweet when its standing still, revs up nice turbo comming in ok, just a slight whistle when backing off. This probably is just the tensioner though.
Just as a point of interest what was the code and description given? we don't see many codes for MAF's only when the engine has been run with it disconnected and what diagnostic equipment was used.
Sorry Chris I didnt take note of the code, or the model of machine other than it was a snap on one.I will find out for you this afternoon when I take the kids in for eye test.
Any how that is the problem fixed as far as I can tell, gave the wagon loads of beans up hill and it run fine. I am just annoyed with the slight squeak when you back off on the throttle I will have to investigate further.
Now anyone know of a decent mkIII for sale in the south west?
Yep I get that and on the MK3 aswell more so when reversing up my driveway