VW Passat B6 2006 1.9 TDI PD issue

Hello, everyone,

greetings from Vilnius.

Done some search about my problem but found so many problem solving suggestions that now at the moment I'm really confused. Maybe anyone can help me sort it.

From a beginning. About two months ago I bought a vw passat b6 TDI PD with 1.9 BKC engine. It had 140k miles. After I bought it I check mileage on VCDS, it showed 216k miles. (stupid me to buy it). It had new dual mass flywheel, rebuilt turbo charger and conditioner compressor. It was driving fine, well, at least, I felt a lack of power (77 kw), but I thought it was normal considering a weight of a car. I had a (I thing) normal fuel consumption, on idle when warm it was 0,24 U.S. gallon per hour and when going 60 mph about 40 mpg. So no big problems.

Three weeks ago suddenly whole car started shaking on idle at a junction. When it gets higher rpm than idle - it's okay. So I drove it home and plugged in VCDS. It showed me P302 #2 cylinder misfire. Hm.. Then I noticied, that my mpg got poor - when driving it is about 30 mpg and on idle, when it shakes - it is 0,48 U.S. gallon per hour.

When I'm starting it cold - no problems. Idle is smooth. And only after 10 ir 15 minutes of ride, when engine is getting warmer - it is starting to shake on idle. Sometimes idle is okay when hot, but rarely.

Checked VCDS for engine meas.blocks group13 for Injection quantity deviation:

1# -3.01 mg/str
2# 2.99 mg/str
3# -0,45 mg/str
4# -1,29 mg/str

Then I fueld my tank to the top and added some injector purge. But didn't ride a lot, so no difference yet. Then I found, that many people have idle shaking problem with TDI PD. And many of them fix it with camshaft timing adjustment. So I checked mine it was -2.5. I've tried to make it between 2 and 5 more to a 5, bet managed to do only 5.4. I believe that it isn't big deal, so left it.

Some driving test. And there's still idle shake problem but I had no lack of power like when I bought a car. It was really more fun to drive. And MPG didn't change it was still poor. Yesterday I've tried to start my car on a warm garage. But I had to try to do it 3 times and it started hard, but smoothened.. So it is getting worse. And I really don't know where to start..

When I was adjusting camshaft timing I noticed, that my timing belt tensioner isn't tight as it should be.


So now I bought new timing belt kit and I am replacing it at the moment.


I have many doubts on what should I do next if it won't help. Could loosen tensioner make this kind of symptoms? Maybe I have fault injector(-s)? Maybe it is a camshaft with lifters? Could they make this kind of symptoms? I'm on a low budget at the moment I can't just replace everything. And I need my car everyday badly .

So my next steps are:
1. Finish with timing belt kit.
2. Clean egr (btw it is not in a bad shape, clean enough) and intake manifold isn't clogged.
3. Check injectors wiring loom resistance.
4. Adjust injector clearance lash.
4. Inspect camshaft lobes and lifters without removing them (don't have special tools).
5. Check compression on cylinders but only in few days.

Any other suggestions, tips on this problem? I'll keep updating it.

I guess the injectors are shot. Nothing what you mentioned will cure the problem if it turns out they are defective.

The TB tensioner which you think is loosened is simply because of belt streched. Also, the tab should be in the window only engine being at room temperature while doing the TB job.

Cleaning the EGR will not hurt but I doubt it will improve anything.
Also, I suspect that the camshaft will have some wear. You might have some problems adjusting the injector lash clearance due to that (it's difficult to locate the lowest injector pisition with worn cam, unless you have a special gauge).

Oh, and I think you went too advanced with th cam timing. That engine should feel happy with -1.0, -0.5 or 0.0 value.

Finished with timing belt...
Checked and cleaned injectors wiring loom.
Inspected my camshaft lobes. Camshaft need's replacement. I can see copper some places and few lobes doesn't look normal.
Checked lifters and they didn't have any wear, they are all with blackened top. I guess last owner did lifter change at some point but didn't change camshaft.
I didn't do injector clearance lash adjustment. I'll do it, when I change camshaft.

So..

Car started normally. Checked Torsion value (camshaft timing) it was -2.5.
Checked group 13 on VCDS for injection quantity deviation 1,3,4 cylinders were okay, second one started to drop from 2.99 until 2,71.

Stopped an engine and went to adjust camshaft timing. Now it is 1.0.
Checked group 13 again, and all four readings went down:

#1 -0,19
#2 -0,42
#3 0,19
#4 0,45

And for the first time, I saw 0,18 gallons per hour fuel consuption...

Woohoo. Was it only camshaft timing problem???

Then I've tried to do EGR valve test on VCDS because I have it failed last time. So test begun, rpm ~1400. Activating/deactivating EGR valve and readings are normal. Then finished test, rpm dropping...and..

It started again.. shaking on idle...(((

Turned on group 13 in VCDS. And cylinder 1 went -3.01, cylinder 2 went 2.99. Then I accelerated a bit.. on both cylinders readings started to drop. Left on idle, few seconds no shaking, normal 13 group readings, and again.. shaking.. cylinder 2 goes 2.99.

What's happening? Is it really failing injector? Shouldn't it be not working all the time? Maybe it is related to something else?

You might want to swap the #2 injector with #3 to find out if it's injector or wiring loom issue.
However, pulling the injectors will require the seals to be replaced. If you are tight on money, you can skip that while you are testing things. But once you finish with the injectors (replacement, rebuild, etc), you should replace the holddown bolts and seals as you will end up in diesel getting into oil - a really bad thing..

Some update. DIdn't do much.

Done compression test on my BKC:
#1 - 470 psi
#2 - 470 psi
#3 - 470 psi
#4 - 490 psi

Just ordered new camshaft, camshaft bearings, lifters, camshaft seal, injector rebuild kits, tandem pump gasket, new bolts. And bought few used injectors, I'll get them to test.

It looks like I have everything to go back on the road again.

Since I have to take off timing belt (just replaces it two weeks ago) from camshaft, that means I have to release timing belt tensioner...

My only question is:

Do I have to replace timing belt tensioner? Some people say, that you can only tighten timing belt tensioner once..

If I have to. I am using contitech timing belt kit. But I can't order only V55739 contitech timing belt tensioner. Can I buy tensioner from other brand?

No, you do not have to replace the tensioner. The nut that tightens the tensioner in place can be reused as well ( this nut is usually supplied in the kit but can be reused a number of times).

If you have the mechanical tensioner(no hydraulic cushioning) and you are removing the belt from the cam sprocket( to replace cam shaft) you should have a pin for locking the tensioner in the counter clockwise position. After loosening nut rotate counterclockwise using hex wrench( may have to cut to shorten to get it in hex socket of tensioner) and insert pin. Remember there is a tab on the back of the tensioner that is in a slot during this procedure( do not try to pull forward or remove during this proceedure). Once the pin is in place you can loosen the nut holding the tensioner as much you want. But the holding tab must always go back into the slot when removing pin and adjusting tension.

Hopefully others can verify for your motor from Europe/Asia

Yep, you don't need to worry about replacing the tensioner - it's fine.

Also, the tensioner can be released and retightened without the need to remove the engine mount so no need to mess with engine mount bolts, support the engine, etc. However, for this to accomplish you will need a 6 mm "L" shape hex which has got its shorter end cut.

Use a special break-in oil for your new camshaft, this is very important!
This is the procedure I'd suggest to follow:
1. Drain the old oil.
2. Remove the oil pan, clean all the metal shavings at the bottom of the pan. Those metal shavings have accumulated there from your fialing camshaft. And no, they don't get flushed when old oil is drained. At the same time inspect the oil pickup tube and its strainer - quite often it's clogged with metal debris. Reinstall the oil pan.
3. Replace the oil filter. Once the oil pan sealant has cured, refill the engine with the break-in oil. Start the engine, let it idle for a while.
4. Proceed replacing the camshaft.
5. Once you have replaced the camshaft, turn over the engine at least 2 times to make sure everything is okay.
6. Start the engine, let it idle for ~20 seconds, then bring the RPMs to 2000 and keep it there for at least 10-15 minutes. Then vary RPMs between 2000-3000. The break-in procedure should take no less than 25 minutes.
7. After initial break-in, take the car for a spirited spin. Use various techniques, RPM variation, etc.

The oil change before starting the cam replacement is required so that you won't have dry startup after cam replacement - your worst enemy. Special break-in oil is also needed, usual everyday oil is not the best choice for this.

Hey, thank's for advice. I'm still surfing for more info on replacing camshaft and injectors. I'll be doing it next saturday. For now, little update:

I've ordered three used injectors from UK and tested it at some local shop.

Below are results. There's different rpm's, fuel injection quantity limits and actual fuel injection quantity.

What do you think? Is it normal? Or I have to go check other two and choose best one? Test is 25$ each.

I'll be replacing only one injector. Others are fine by VCDS.

one more thing

You might want to take your egr valve apart. If it sticks open, or partly open, the car idles rough. This happened to me. also splice a clear hose on your return line to tank, and make sure no bubbles. a loose or leaking injector copper gasket can cause similar problems. good luck.

Excellent post. Thank you very much!!