Low rev hesitation/judder

[jmejamie]

Hi All

My car is a 2002 Audi A6 1.9 TDI 130BHP AWX engine.

I'm having a weird issue with my car which is basically most noticeable in two circumstances although knowing the car for as long as i have i can feel it even when most don't find it as obvious.

If i'm in 5th gear and anywhere between 1200rpm to under 2000rpm the whole car shakes itself rather viciously even under heavy or light acceleration. I can slightly feel it in 4th gear under the same circumstances. Then i started to realise that when coming into my estate (full of bloody speed bumps) if i keep it in second gear going over the bumps (no clutch) and then lightly accelerate away there is a second or 2 of this weird judder again but far less violent then the higher gears previously mentioned.

As well as the above i do get a slight pulling away judder which is annoying and i assume is related to the above?

I originally thought it was because the clutch was on its way out however that's been replace (twice) once with LUK then i didn't like how harshly is changed gear so had it replaced again with SACHS. I was then advised maybe this was being caused by the CV inner joints so i replaced both my drive shafts and again still no luck. All the intercooler pipes have been checked to make sure they are tight and to be fair over 2000rpm if i put my foot down the car generally flys...

I am honestly getting to a point where i don't know whats causing this anymore and would really like some advice!

I did get to borrow VCDS off someone and did some log files but i don't really have a clue what the hell i'm doing i've just gathered what seems to be the most common groups and logged them for someone who can maybe look at them and make some sense for me?

LOGS: Car logs.zip

Thanks in advance!
Jamie

[AudiAvantAwx]

Hi
I am no expert
Did you try the usual things?
Egr,Maf,Sticky Vanes on turbo,Any of the vacuum lines damaged or kinked,Fuel filter been changed recently?

Cheers

[jmejamie]

Hi AudiAvantAwx

Yes I have had the EGR removed and replaced with a Dark side Developments Delete Kit. It's also been mapped out on a remap as well.

MAF unit went a couple months back and I replaced with one from a scrap yard which brought the car back to the power it was lacking when faulty. Hoped maybe someone would be able to read my logs and tell me if those bits are ok with the car

Turbo has had the Mr Muscle treatment twice and the arm moves nice a freely!

Vacuum lines have been replaced and also simplified by removing the N18 valve for the EGR and the anti-shudder valve also.

The fuel filter was replaced by a garage maybe 6 months ago or something around that. I read online about the return feed O-rings being important to replace and they aren't well known for the little details so I did actually buy another one a couple days ago and replaced the fuel filter and the O-rings for piece of mind!

Really starting to run out of ideas what's causing the issue! Was hoping the log files would hold the secret!

Thanks for your reply

Jamie

[Rob69]

Did you get the flywheel replaced at the same time as one or both of the clutch kits? If not it could be the dmf, could also be one or more engine / box mounts.

[jmejamie]

Hi Rob69

Yes I had a new clutch and flywheel both times! So it was a full LUK kit and then a full SACHS kit...

Had the snub mount replaced because that was destroyed and had destroyed the exhaust flexi as a result.

Is there an easy way of working out if engine mounts or gearbox mounts are dead/dying?

Thanks,
Jamie

[mrcheesbrough]

Hi All

My car is a 2002 Audi A6 1.9 TDI 130BHP AWX engine.

I'm having a weird issue with my car which is basically most noticeable in two circumstances although knowing the car for as long as i have i can feel it even when most don't find it as obvious.

If i'm in 5th gear and anywhere between 1200rpm to under 2000rpm the whole car shakes itself rather viciously even under heavy or light acceleration. I can slightly feel it in 4th gear under the same circumstances. Then i started to realise that when coming into my estate (full of bloody speed bumps) if i keep it in second gear going over the bumps (no clutch) and then lightly accelerate away there is a second or 2 of this weird judder again but far less violent then the higher gears previously mentioned.

As well as the above i do get a slight pulling away judder which is annoying and i assume is related to the above?

I originally thought it was because the clutch was on its way out however that's been replace (twice) once with LUK then i didn't like how harshly is changed gear so had it replaced again with SACHS. I was then advised maybe this was being caused by the CV inner joints so i replaced both my drive shafts and again still no luck. All the intercooler pipes have been checked to make sure they are tight and to be fair over 2000rpm if i put my foot down the car generally flys...

I am honestly getting to a point where i don't know whats causing this anymore and would really like some advice!

I did get to borrow VCDS off someone and did some log files but i don't really have a clue what the hell i'm doing i've just gathered what seems to be the most common groups and logged them for someone who can maybe look at them and make some sense for me?

LOGS: Car logs.zip

Thanks in advance!
Jamie

Sounds like it could be a failing injector loom. What mileage does your engine have on it. The symptoms sound very similar to our 130 TDI Alhambra. Changed the loom, MPG up and smooth as silk now. With the VCDS you should be able to get some fault codes from the ECU if this is the case.


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[jmejamie]

Hi Mrcheesbrough

I did read a fair amount about the injector wiring loom, didn't know if it was going to be something i might need to consider! The cars done about 165k! I will say my MPG isn't the most fantastic and to be honest the shaking does feel almost like a misfire... I did scan it multiple times with VCDS when i've borrowed it in the past however its never come up with anything. Then again it never came up with anything when the MAF unit went bad so its not to say its not the loom!

Thanks for your input, i hope this will be the solution! Will grab a loom and gasket off eBay and maybe take it to my mechanic to avoid me doing more harm then good

Jamie

[mrcheesbrough]

Hi Mrcheesbrough

I did read a fair amount about the injector wiring loom, didn't know if it was going to be something i might need to consider! The cars done about 165k! I will say my MPG isn't the most fantastic and to be honest the shaking does feel almost like a misfire... I did scan it multiple times with VCDS when i've borrowed it in the past however its never come up with anything. Then again it never came up with anything when the MAF unit went bad so its not to say its not the loom!

Thanks for your input, i hope this will be the solution! Will grab a loom and gasket off eBay and maybe take it to my mechanic to avoid me doing more harm then good

Jamie

Sounds about right. Our Alhambra has 155k on the clock. Just so you know a genuine loom is around £65. Watch out for any ‘refurbished’ looms on eBay as the fault is caused by the breakdown of the wiring which I would think is difficult to refurbish. Probably no need for a gasket - the one on the Alhambra is a reusable rubber one, unlike the older cork/rubber type used in the 90s. If you know enough about VCDS you can read the measuring blocks for the injectors while the Car is running. Chances are one of them will be reading a lot higher then the other three. Fingers crossed for a positive result.


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[jmejamie]

Thank you very much for your help! I will actually have VCDS again in a couple of days so maybe I will check the injectors as you mention on there and log it. Hopefully it will show up as that being the case. For that kind of money I will just get a genuine one then, don't want to chance it!

Thanks again! I will definitely come back on this to give you any updates

[AudiAvantAwx]

I'd say injector wiring loom would be a good shout too.
For that money anyway worth a try
Fingers crossed for u,let us know if it works
Happy Christmas