[mr.pulkkinen]

Hi Guys,

I have som trouble with a A4 AVF TDI 1.9 PD

General Rough Idle and vibrations at idle

Sometimes 17675/P1267/004711 - PD Unit Injector: Cylinder 3 (N242): Regulation Range Exceeded appear.

http://wiki.ross-tech.com/wiki/index.php/17675/P1267/004711

All PD are tested and showing 0 0 0 0 in Channel 18

I did a wiring checkup and all PD have same resistance. 0.40 ohm including wiring

What to do.

Cheers from Denmark.

 

[chittychittybangbang]

Check channel 13 in engine measuring blocks for injector balance. Here is a screenshot from this article on how to check timing. http://www.myturbodiesel.com/1000q/multi/PD-adjust-Idle-TDI.htm

 

[mr.pulkkinen]

Adjust Torsion

Ok i will try to adjust timing to +1 tomorrow. It is now 0.0 to 0.5 but maybe 1.0 to 1.5 is better.

Could worn camshaft Cause the rough idle problem.

Car performs well no issues. 220km/t-140 miles is no prolem at all

 

[Vent5]

Could worn camshaft Cause the rough idle problem.

YES. Do an inspection. Badly worn lobes = bad idle. If they're not that bad look elsewhere.

But that code you have is:
Possible Causes

* Regulation times exceeded
* Contact resistance

Possible Solutions

* Check Injectors and Injector Wiring
o See Meas. Value Block 018
o Check Resistance of Injectors/Wiring

 

[mr.pulkkinen]

I have tested the wiring and contact resistance. Everything is ok. 0.4 to 0.5 ohm in all PDs Audi says 0.5-0.8 Ohm

Block 18 is all 0 0 0 0

The Camshaft seems at bit worn on cylinder 3 and there is sometimes a bit valve noise. Sounds like a leaking exhaust, only sometimes. The engine has a deep sound from cylinder 3-4 area hearable without the cylinderhead cover mounted and engine idleling.

All hydralic lifters seems easy to twist when camshaft is not pressing them down.

Should i replace the camshaft and lifters before driving the car?

 

[mr.pulkkinen]

Here is idle log

 

[freerider]

....is the camshaft worn to the point where it will cause the #3 injector to get like that? Maybe the injector is sticking too? Have you checked the EGR and how is the flywheel? I believe these can also cause a rough idle. I thought the camshafts wore first on the ends? I would do a compression test and leakdown test before going to the trouble of changing the camshaft though. It's a lot cheaper and it could reveal another problem.

 

[mr.pulkkinen]

....is the camshaft worn to the point where it will cause the #3 injector to get like that? The cam shaft is only worn at Exhaust and Inlet Valves lift no visual worn at Injector Lobe.

Maybe the injector is sticking too?

I ran 3 times injector cleaning through the engine with 2-3 weeks.

Have you checked the EGR?

I will try to blank it of later today

and how is the flywheel? I believe these can also cause a rough idle.

Think flywheel is ok no vibration at hard acc. or low rpm driving.

I thought the camshafts wore first on the ends?

I would do a compression test and leakdown test before going to the trouble of changing the camshaft though. It's a lot cheaper and it could reveal another problem.

What is best way to test compression in a PD engine

is the camshaft worn to the point where it will cause the #3 injector to get like that? The cam shaft is only worn at Exhaust and Inlet Valves lift no visual worn at Injector Lobe.

Maybe the injector is sticking too?

I ran 3 times injector cleaning through the engine with 2-3 weeks.

Have you checked the EGR?

I will try to blank it of later today

and how is the flywheel? I believe these can also cause a rough idle.

Think flywheel is ok no vibration at hard acc. or low rpm driving.

I thought the camshafts wore first on the ends?

I would do a compression test and leakdown test before going to the trouble of changing the camshaft though. It's a lot cheaper and it could reveal another problem.

What is best way to test compression in a PD engine

 

[chittychittybangbang]

You do a compression test on a PD engine through the glow plug holes. There's an article in the FAQ section on this, the specs are the same as pre-PD engines. What you're really looking for is a difference in #3 cylinder.

 

[mr.pulkkinen]

ok and if there is a difference what would it then be?

Cylinderhead Gasket was changed with the timing belt 5000km ago. Just to visual check engine inside. Fine bore and no scrathes, and still borescratches visible.

 

[Brian Kydd]

I have tested the wiring and contact resistance. Everything is ok. 0.4 to 0.5 ohm in all PDs Audi says 0.5-0.8 Ohm

Block 18 is all 0 0 0 0

The Camshaft seems at bit worn on cylinder 3 and there is sometimes a bit valve noise. Sounds like a leaking exhaust, only sometimes. The engine has a deep sound from cylinder 3-4 area hearable without the cylinderhead cover mounted and engine idleling.

All hydralic lifters seems easy to twist when camshaft is not pressing them down.

Should i replace the camshaft and lifters before driving the car?

Are one of the lifters bent,( on top centre) common on cylinders 3/4. usually caused by wrong oil?

 

[Brian Kydd]

Are one of the lifters bent,( on top centre) common on cylinders 3/4. usually caused by wrong oil?

Ps hard to see without Cam removed / loosened.

 

[mr.pulkkinen]

Updated

I will change Injector 3 tomorrow. Then I will have a look at the lifters on cylinder 3/4

Heres an updated Idle log showing the fault when it is worst.

Im pretty sure that Injector 3 is the reason to all my troubles.

 

[mr.pulkkinen]

Injector Exchanged

Hi Guys, just a little update.

Exchange the Injector and everything seems fine. But i still got the issue.

Compression is tested and all cylinders are within spec.

No visual damage or wear to the camshaft lobes

Heres the issue.

Engine Idleling with Coolant over 80degress Celsius (Car can idle and run like this as long as you stay under 2500 RPM)

If Engine are Reved over 2500 RPM this happens.

Issue is solved if you shutdown engine and restart right away and keep the RPMs under 2500 the car can again run as long as you want.

Fault 17675 is stored again as soon as the engine has been reved over 2500 RPM

What to do about it.

Injector exchanged
PD Harness exchanged
Dieselfilter exchanged
Tandempump exchanged

Looking forward hearing all your suggestions.

Regards

 

[chittychittybangbang]

This is puzzling. You've already replaced the wire harness, injector, and checked the camshaft. Is this a DSG transmission? I don't know if a bad flywheel could cause that error code but bad flywheels can cause rough idling and strange engine symptoms. I don't know if it's possible but maybe the injector rocker on top of the PD injector is misadjusted or has somehow become loose? There is a nut and bolt on each rocker that adjusts each injector plunger.

 

[mr.pulkkinen]

Hi thanks for the reply.

The rockerarms nut and adjustment screw is tighten to the limit where resistance is felt and the 225 degress backwards. Then thigten to 30nm

I have been strugling with the car for almost 3 month now. So my opportunites are almost blow away.

The car is not a DSG Gearbox car but a normally 6 speed transmission. I dont suspect the fly-wheel causing the issue. The car is pretty free from normal vibrations when the PD element in Channel 18 is not showing status 47 at cylinder 3

I found some people at SGAF.de talking about that it could be caused by contact corrosion at the harness. Maybee the old Injector caused this issue. What is the best way to clean that out?

New harness again?

Could the cars harness or ECU be defective? All injectors have 0.5 ohm resistance wiring harnes is all below 0.1 ohm each.

Im about to swap injector 3 to 4 to see if the issue follows the injector. To get a glue again. Im pretty clueless and frustrated right now. The car needs to go to MOT within 14 days and cannot pass emissions test with this issue i think.

Again thanks for all the replys. :bowdown

 

[chittychittybangbang]

It's possible you have some electrical fault on the harness. I'm not sure how to check each individual wire harness. Defective ECU are rare but it does happen.

 

[mr.pulkkinen]

Ok so you suggest a new internal harness again?

 

[chittychittybangbang]

No, I'm saying that it's possible there's an electrical fault somewhere else on the wire harness. Did you replace the entire harness back to the ECU? This normally isn't necessary if you can find a fault it's obviously better to fix it.

 

[mr.pulkkinen]

I have only exchanged the old wiring harness in the cylinder head. I will try to test with another ECU first. Second Swap injector 3 and 4 to see if the problem moves. Third make a temporary wire from ECU to injector 3 to see if this solves anyting. Forth Buy a new wiring harness for the cylinder head. Fifth Give in i think