Injector Loom (01 Pass 130TDi)-anyone done?

[andre 2000]

Well gents,

I replaced the loom this morning, it took around an hour and have now got a very smooth running Passat all the way through the rev range!
Misfire completely eradicated.

The old loom plastic carrier broke up as I was withdrawing it, it was very brittle but otherwise all went without incident.

Thanks very much for the information and posts that led me to the problem, wouldn't have had a clue otherwise.

To anyone who has the misfire issue on the TDI PD 130, try this out before spending hundreds on new injectors.

Thanks again,

Andy

[Rolo]

I appear to have exactly the same symptoms as yours. Mine is the same but with 240k. I changed the wiring loom about 65k ago because it completely lost one cylinder. I have removed turbo and that is clean and checked all of the hoses etc and changed N75, MAF & MAP but it still remains the same. If changing your injector loom cures your problem please let me know as I suspect that it could be the DMF. This was replaced 60k ago and the problem started about 15k ago. The loom is lot easier than the DMF! I left the original plastic tray in place and fitted the new wires into this and used a few cable ties to hold it together and keep the wires in place.

If you find out what it is please let me know
Thanks
Ian

[andre 2000]

Hi Rolo,

Yes I can say without doubt the loom has fixed the misfire 100%.
I did the loom on Saturday and have done some 200 miles mostly motorway since then with no misfire or other symptoms at all.

The reason I am so confident is that the problem on my TDI wasn't intermittent, in so much as it did it everytime I got past 60 mph, and whereas others have reported switching the engine off and restarting it cleared the problem, it didn't make any difference to mine.

Having fitted the new loom it has stopped completely.

Mine has done 112k, I have only had it a couple of months but have put 7k on it in that time [I do about 1000 miles a week on business]
It didn't particularly get any worse over this time, and fuel economy was in the low to mid 50s but it definitely wasn't quite right.
I stumbled across Mike McKinstry's post and it seemed way too similar to ignore.

My guess is that as the loom is essentially boiled in oil everytime you use the car, it starts to deteriorate - from other posts I guess from about 60k it starts to show up. I haven't got any diagnostics other than a bit of nouse but I suspect resistance increases in the wiring and/or connectors as they harden through cycles of heating and cooling and this is the root cause of the issue.
Sounds like yours has come around again to change - it strikes me it is a consumable spare!

The part is now £45.45 inc VAT from VW, I had to order it but it was in next day.

I was happy to spend the money as:

1. Given my mileage I spend a long time in the car and want it to run well.
2. I was worried I would break down, typically for me on a rainy dark Friday night
3. If one cylinder is not firing fully, I was unsure as to any whether long term damage to the engine or injector could be caused - I'm sure there are plenty of techies who could answer that one on here, but it is somewhat outside my interest other than fixing the problem.
4. I'm intending to take the car to a very high mileage, similar to yours or beyond so tend to invest in it to help it get there.

Strangely enough, despite other posts, I never suspected the injectors themselves, they are pretty robust mechanically so I just didn't go there.
Just how many have been replaced uneccessarily is anyone's guess, as I believe the diagnostics simply flag up a fault on a particular cylinder.

I too thought about the dreaded DMF, or possibly a bent driveshaft as the whole thing felt like some rotating part was out of balance. Obviously I can't say in your case whether it is or isn't DMF, although many posts talk about symptoms such as 1st gear being difficult to select and tinny rattling noises.
That is subjective though, as lets face it for all it's strengths the Passat was never blessed with a slick gear change, and I have a tinny rattle by way of the rear brake pads which can be heard when the windows are down.

I also get the impression that driving style has a big impact on DMF longevity too - fast starts from lights and riding the clutch, as I am not convinced there is anything inherently wrong with the design, its simply misunderstood.
I ruled it out [and the driveshafts] by revving the car in neutral, and also with the clutch disengaged, and I could still get the misfire to occur - you have to tune right into it though as it isn't as clear when the car isn't under full load.
DMF is possibly one for the future for me, as I can vouch for my own driving style but not for the previous owners.
Having said that I have heard of these cars reaching mega mileages on original clutches and DMFs so who knows.

If you do go for a new loom - and lets face it you've got nothing to lose next to what people spend on new injectors for what I suspect is often the same problem, do watch your old plastic carrier. When removing the old one mine shattered and pieces were thrown into two of the oil galleries underneath. I managed to salvage them before they sank, next time I will drain the residual oil from the head and cap the galleries off just to be safe.

The new loom went in without a hitch, but as recommended by the helpful chaps on here I heated mine up first to be able to bend it in. I would replace the whole lot rather than strip out the wires - you may as well fit it in one go -you've paid for it.

I hope this helps, feel free to check with me again as my miles rack up.

Andy

[trevMk2]

Hi
Having similar vibration type problems with my 2001 TDi 130 (AVF) as others on here - no fault codes. Was planning to change inj wiring loom (at worst it costs me £50 to rule it out - various folk on here say its only about £45) - however my local ever helpful dealer wants £87 plus VAT. Cant source it anywhere else (Murrays, ECP, GSF etc..) has this really doubled in cost (or is £45 trade price) or do I need to try another dealer in Bath/Bristol area (surely all dealers the same price ?)

Thanks

Trevor

[Rolo]

Part No 038971600 £39.52 + vat £45.45 full retail price. If they want more then they are thieves!

hope that loom cure misfire. Heat it with hot air gun to soften plastic and it will bend in to passat head.
Think that mine may be due to DMF
cheers
Ian

[andre 2000]

£87 + VAT

Mine was £45.45 inc VAT direct from VW 2 weeks ago.

The only difference I can think of is the engine code. I am not sure if AWX types are massively different from AVF but something seems amiss.

There was no mention of trade discounts etc. when I got mine from a main dealer in Stockport - at the price you've been quoted I would either let your dealer know this, or go to another dealer and get one posted to you.

Cheers

[Mike McKinstry]

Ours is AWX and was about £45 for loom.

[trevMk2]

Many thanks for correct part No – I went back to local dealers and got a more sensible parts man (1st muppet quoted me for something completely different)
Regular readers will know that been suffering from vibration (most noticeable at motorway speed) on my wife’s 2001 TDi130 and saw on here that often this is due to ageing injector wiring loom. So for the sake of £45.45 I thought I’d change it. Here how

• Buy wiring harness adaptor from VW (038 971 600 £45.45 inc VAT) looks like this
• 
• Remove plastic engine cover (3 10 mm nuts) & insulation

• Disconnect air duct that runs from intercooler to the inlet manifold
  
  • Unbolt bolt connecting duct to bracket (10mm bolt –captive nut in bracket)
  • Unplug sensor multiplug
  • Disconnect intercooler hose (pull spring clip upwards to release)
  • Disconnect duct at manifold end ( mine was very oily so I taped freezer bag round it so that no muck fell into head later)
  • Disconnect 4 clips holding misc hoses & fuel hoses to air duct
  • Manoeuvre duct out of way
  
  
• Disconnect loom electrical connector (approx ½ turn anticlockwise)
• Remove 2 bolts/studs at back of head that retain loom housing (10 mm) see pics

• Remove top portion of cam belt cover and disconnect breather hose from head
• Remove cam cover (10 mm captive bolts -13 off)
• 
• Unplug 4 electric connectors from injectors and clip into loom rail see pic
• Withdraw loom (metal lugs will snag and plastic rail will probably break – be careful that bits don’t fall into head)
• Carefully heat new loom rail about quarter way, mid point and three quarter way with hair dryer/hot air gun (on low/mid setting) to soften it just enough to enable it to be bent into crescent shape so that it can be threaded into head. White mark on loom housing faces up (about 2 oclock)

As Mr Haynes would say the rest of the assembly is the reverse of dis-assembly (torquing cam cover bolts to 10 Nm – no torque setting listed in Haynes for loom nuts) .

Only tricky bit is manoeuvring old loom rail out of head and new loom in – that is difficult only because the rail is 330mm long and the gap between the head and the bulkhead is less than half that!

Only tools that you will need are 10mm socket (1/4 inch best as space limited esp bottom bolt of loom housing ), torque wrench and a few flat blade screwdrivers for prising open pipeclips etc.. Took about 1 ½ hours working quite slowly and taking pics as I went along. Read on here that “check engine” warning sometimes appears after doing this work – didn’t happen with me – maybe just lucky.

Has it fixed it ? maybe - does seem a bit smoother but wont know for sure until we do some motorway work.

I’ve got good info of here in the past - hope this helps somebody.


PS

Is this amount of gunge in the duct normal ? or have I a separate problem ?

[andre 2000]

Glad to hear you got sorted out with the right price in the end.

If it helps to reassure you, the duct on mine was at least that gunged up, but has done over 100k so just wiped out what I could see.

Cheers
Andy

[shazzam]

i think i may have to do this soon, does anyone have any pictures showing the layout of wiring etc under the rocker cover, i just want to see what its all meant to look like before i start taking it apart. prefer to know what to expect rather than dive in blind... lol