# Timing chain Failure on 08 FSI . Rebuilt, now severe drivability issues.



## ziker (Dec 7, 2014)

**FIXED* Timing chain Failure on 08 FSI . Rebuilt, now severe drivability issues.*

So I will try to make this as short as possible but its gonna be long. I have a friend whos daughters 2008 VW jetta with 72k broke down and was towed to my house. Im a capable technician and own a competitive track car that I have built the motor in. I know my way around most VW but dont have alot of internal experience with them. 

So the car is a 2.0 FSI engine. I found a broken chain so I pulled the head and rebuilt it. New intake valves, seals, chain, tensioner, T-belt, plugs, cam sensor. I put it all back together and the car ran great at idle. It lacked power upon driving it and had a timing code p0016. So I checked many sources and decided to drive it for a while and see if it was just the chain seating in (I know it sounds crazy but found it as a recomendation and have found VW to be full of black magic). The car had NO power and shifted terribly(dsg) but it drove so I gave it a day or two. It had very loud blow off sounds and weird squirell in intake noises from the Diverter valve(due to the timing being off as found later).

Then it shut down while coming to a stop suddenly. It would idle but surge occasionally and if it was revved up it would stall when it returned to idle. So I pulled the drum (cam chain cover) and retimed it , it was off 1 tooth ( I used the locking tool initially BTW so it is possible to still have it off with the tool, My theory is that it needs more tension on the tensioner then the spring provides so it had to be run to lose its initial time). After retiming it idled great but still surged occasionally and would stall. It was almost undriveable. Surging and stalling at stops. I unplugged the MAF and the car will run ok and is driveable but still powerless. It sets a MAF code but was driveable. 

I have tried many things. I think the MAF is good and is within limits, Its at 4-6 Grams at idle and around 165 at full throttle. I swapped with a new one but no change. The O2's are switching , The throttle body has been reset with my Launch x431. I cannot find a vacuum leak. I have sprayed(for vacuum leaks) and visually inspected the intake system and head. Only non stock part is the Neuspeed intake. I do not think there is a compression issue or a timing issue anymore as the car is better with the MAF unplugged. It defaults out to 365+ Grams when unplugged. Vehicle reacts correctly to having the oil cap and dipstick pulled (stumbles). 

Tonight It didnt want to drive correctly with the MAF unplugged but 1 mile later it was fine again and driving. Tried it again 2 hours later for 20mile commute home and it ran fine. I started trying to think logically about why it suddenly got worse and came up with this. Perhaps the DV valve got tired of trying to regulate the overboost condition caused by the incorrect timing and gave up. I pulled it out but the diaphram is intact and I actuacted it in both directions with a power probe. It moves like I assume it should. It did come out in 2 pieces which I am unsure if that is correct. 


What am I missing? I had a VW tech (unsure of experience) look at it and he was stumped. I tested fuel pressure, Low pressure pump fluctuates between 40-90 rapidly (like it should as its a feeder for the high pressure). 

I own this car till this job is done. Thanks for the long read. Lets see if this can be solved. *problem has been fixed by an indy shop I trust, once the original intake was installed there was a distinct whistle sound. After smoking the intake it turned out there was a hole in the intercooler. No codes for over 200 miles.... *


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## ziker (Dec 7, 2014)

Lastly, using my launch I had a friend drive while i reviewed a few pieces of data. The car was making 0 boost with the MAF plugged in while trying to drive. It appeared to be boosting with it unplugged.


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## lausch (Mar 29, 2002)

You sir, are the best friend ever. I wish I had something more to offer. Good luck.


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## quietA3guy (Oct 12, 2007)

Codes? And DV should be one piece.


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## ziker (Dec 7, 2014)

No codes when the mass air is plugged in. Even when trying to drive with it sputtering there is no codes. The diverter is a magnetic driven solenoid. The moving portion came off. I watched a few videos and it looks like its supposed to be like that, although I did not see the black plastic cap that they pull off the diaphram in every video. maybe it was lost by a previous repair.


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## [email protected] (Sep 18, 2012)

I will start as if the head was never removed and ask.. have you changed the plugs and coils? 

You have re-timed the car and checked the timing points?


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## ziker (Dec 7, 2014)

Plugs new but coils are original. Doesn't have misfires per data stream. Timing Is Now Spot On But severe drivability problem started While The Timing WAS Off After About 80 MILES of driving. my thought is that with the timing being off the car was constantly over boosting. Which would cause diverter valve to go crazy for those 80 miles. Which may of ruined it.so new ones on the way. I actuated the old one with power probe off car. Seemed to move ok but who knows. No tears in diaphragm . I'm stumped


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## [email protected] (Sep 18, 2012)

You know the more I read this and think about it. I would start with a leak down test of the motor. If the timing chain skipped a tooth then there is a possibility of valves being bent in that head. 

I would start there to be honest.


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## DasCC (Feb 24, 2009)

lausch said:


> You sir, are the best friend ever. I wish I had something more to offer. Good luck.


:thumbup:


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## ziker (Dec 7, 2014)

I rebuilt head with new valves.


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## [email protected] (Sep 18, 2012)

ziker said:


> I rebuilt head with new valves.


I understand but when the chain skipped.... Could have bent valves.


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## ziker (Dec 7, 2014)

Don't think it's a compression issue but I'll run a leak down of the weekend. Chain never skipped. Initially I timed it without the tool so it pulled a tooth off on the intake but then I checked it with the tool and it seemed ok. Not enough to interfere. It is timed correctly now.


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## ziker (Dec 7, 2014)

Diverter valve made no difference. Maybe I have a throttle body issue. I feel like im shooting in the dark without a well sorter diag tool.


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## 2006_A3_2.0T (Jan 11, 2013)

vagcom?


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## ziker (Dec 7, 2014)

Don't have a vagcom. I have a launch x431 tablet. I can do many things but not sure if it's resetting the throttle properly.


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## cameron2pt5 (Oct 19, 2006)

Did you install new injector seals or re-use the old ones? I second the leakdown test idea. Also is the cam phasing working? I'm not talking static timing, but can your diagnostic tool log cam angle?


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## ziker (Dec 7, 2014)

New injector seals. The are felpro blue rings . I can't tell if the phaser is operating properly. will check cam angletomorrow


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## ziker (Dec 7, 2014)

So I spent another hour looking at it. I tried to reset the throttle body with a friends autel. I tried it like 6 times. No change. I checked the timing with the scan tool. its spot on. Cam timing matches the cars timing demand. Interestingly enough while im driving I will get an intermitent bang like the car is asking for a downshift prematurely. This car is getting over my head. May be headed for the dealer. Only other thing I noticied is when I go to reset the throttle body it says throttle position 1 11.6 % and throttle position 2 84.4% or something very close to that. Mayybe my TB isnt closing all the way?


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## ziker (Dec 7, 2014)

So i dropped the car off at the dealer. I am not optimistic that this will have good results. I can almost guarentee I will be updating this post in a day or two that Im out the diag and they found nothing or found something super expensive that will not fix it.


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## cameron2pt5 (Oct 19, 2006)

Lost sleep, rock in your gut feeling... Been there done that! Hoping it's good news for ya!


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## [email protected] (Oct 23, 2008)

If the camshaft got locked up when the chain broke it could've quite possibly sheared the keyway on the lower timing sprocket for your timing belt which are causing these issues. By your symptoms, this sure sounds like what is going on as your mechanical timing is retarded


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## ziker (Dec 7, 2014)

I checked the desired timing and the actual timing using the scan tool and they are spot on. Dealer said it had a vacuum leak. We replaced the pcv. it now doesnt stall but still wont drive (jerks bucks bangs). Coincidentily, I worked on a 2009 a4 tonight that was bucking jerkking and banging that felt like the tranny was falling out. had 2 bad coils with no codes.... maybe I should swap coils.


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## Mkv gti 5 (Mar 17, 2014)

Hi, I had this problem after doing my chain and tensioner. The problem is the tension need to be on bottom side of the chain along bottom of tensioner back around to the top side of the intake sprocket. As the tensioner is hydronic it will take the slack up. As long as you used the proper cam holder on the head your timing will be spot on. 
Ps as the chain comes along the bottom make sure you turn intake cam sprocket into advance again you will need a special tool or I have seen people make their own. 
In box me if you need more help


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## ziker (Dec 7, 2014)

So the timing is on. I originally have a p0016 then reset the timing and now it is correct. I have the car dropped off with another tech as I am now too frustrated. He did a pcv which caused it to no longer stall but it still bucks and cuts out. I had a a4 at work doing something similar with no codes a couple days ago that turned out to be 2 coils. Found with the misfire counter. So its possible this is the problem. Other tech will try it.


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## Sandman333 (Oct 28, 2002)

ziker said:


> So the timing is on. I originally have a p0016 then reset the timing and now it is correct. I have the car dropped off with another tech as I am now too frustrated. He did a pcv which caused it to no longer stall but it still bucks and cuts out. I had a a4 at work doing something similar with no codes a couple days ago that turned out to be 2 coils. Found with the misfire counter. So its possible this is the problem. Other tech will try it.


How high was it over boosting? I've had a APR Stage I on my car almost since new, and I regularly hit 20 PSI. 91K miles and no problems due to high boost. 

You could be on track with the coils. Mine started to go out around 65K miles. I replaced all 4 along with the plugs (tried plugs first and it made the symptoms go away for a few days) and it fixed the problem. Misfires started showing up under high boost and eventually the boost level required to trigger a misfire started falling. After a week or so it was all but undriveable, as anything near positive manifold pressure started triggering misfires. I got OEM coils from www.1stvwparts.com. They were the cheapest I could find.


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## bilagain (Sep 26, 2003)

any updates? curious what the issue was. (and hate it when i can't figure it out myself!)


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## ziker (Dec 7, 2014)

No worthwhile update. I have it at another shop that I trust. They want the original intake to start better diagnostics. They say the car is 2 grams over spec at idle per the mass air. Bummerrrrr.


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## ziker (Dec 7, 2014)

*cracked intercooler fixed this car*


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## bilagain (Sep 26, 2003)

glad to hear it was resolved! 

my timing chain failed Jan 4, had popped low oil pressure first and then stalled. got it repaired and after about 20-30 minutes of driving, low pressure light comes back on. replacing sensor tomorrow.


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## 08vwpassat2.0tfsi (Oct 15, 2021)

Mkv gti 5 said:


> Hi, I had this problem after doing my chain and tensioner. The problem is the tension need to be on bottom side of the chain along bottom of tensioner back around to the top side of the intake sprocket. As the tensioner is hydronic it will take the slack up. As long as you used the proper cam holder on the head your timing will be spot on.
> Ps as the chain comes along the bottom make sure you turn intake cam sprocket into advance again you will need a special tool or I have seen people make their own.
> In box me if you need more help


 hey I have a serious problem I do not have the tool my passenger mount failed and timing stopped redid head and now I can’t get it to run it with it and try to start if the pedal is to the floor and u continusly crank the engine but won’t actual start please help me my crank and ex cam are timed according to marks but I’m unsure on intake cam plz plz plz help I miss my baby


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## sauce martin (10 mo ago)

*I currently have the the same problem, but more pronounced. My 08 3.6 wagon runs like crap at anything below 2500 rpm and then takes off like a raped ape afterwards. The chains were replaced at 120,000 and it only has 140,000 now. I replaced the high pressure fuel pump but the sensor on the bottom of it bit the big one about ten thousand ago so now it tries to give too much fuel until I go past 2,500. Yes I change my oil a lot*


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## Darepoole (Sep 3, 2019)

sauce martin said:


> *I currently have the the same problem, but more pronounced. My 08 3.6 wagon runs like crap at anything below 2500 rpm and then takes off like a raped ape afterwards. The chains were replaced at 120,000 and it only has 140,000 now. I replaced the high pressure fuel pump but the sensor on the bottom of it bit the big one about ten thousand ago so now it tries to give too much fuel until I go past 2,500. Yes I change my oil a lot*


fault codes?


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