Injector nailing?

crazyj

Active member
Joined
Feb 4, 2009
Location
Edmonton, AB
TDI
2009 Jetta Wagon TDI
This past winter my car has been pretty consistently having really loud pinging/nailing (like someone shaking an empty rattle-can really quickly). I want to say it was shortly after I had it taken in after a no-start from intercooler icing up but I can’t say for sure.

It’s not all the time. At least quiet enough that I don’t notice it sometimes. Increasingly worse until 2000rpm under light to mid throttle. Bloody annoying and what’s worse is VW isn’t looking into it other than to have s mechanic test drive it. He figures nothing wrong.

I’ve heard that winter fuel combined with some of the injection cycles for regens, etc can make pretty loud clattering but I’d like to prove to myself that there’s nothing amiss before I go searching for a jugular at the dealership.

What are some tests I can perform to check things out? I’ve got a vcds at my disposal. I’d be willing to purchase a compression tester if that’s something I need to do. Is injector deviation the only thing I can really dig into? I can’t recall the deviations I read but they definitely were not 0.0 across the board. Stethoscope at the top of the injector is loudest/hardest knock on cyl 1, then 2 but that might be the knock from cyl1 carrying over.
 

sandmansans

Veteran Member
Joined
Nov 3, 2013
Location
NJ/PA
TDI
2014 Jetta
It's been in my experience that if youre looking for vcds specific testing/logging, you'd be better suited in asking at the rosstech forums.

Sent from my Moto G (5) Plus using Tapatalk
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
You can monitor the cylinder pressure sensor values, at least to see if one cylinder is way off, but it really should not vary much or the ECU will flag a DTC.

I would try some injector cleaner for a couple tanks, and see if anything improves. I know this is one of the post-fix complaints I hear here a lot: "the car sounds more like a diesel now", which I know isn't very scientific.
 

KERMA

Vendor , w/Business number
Joined
Sep 23, 2001
Location
here
TDI
99 beetle and 04 jetta
VCDS Measuring Values Blocks 140 and 143.
Minimum coolant temp = 50C

Not in regen... If you see one of the fields in MVB 143 = 18.4 while the others are some smaller value, under some load, then that's a bad pressure sensor and or injector. All of them = 18.4, then it means the diffference is enough to put you in "mini limp mode" so to speak.

If you see MVB 140 with one of the 4 fields that remains significantly different from the others = bad injector

Peak cylinder pressures are not all that relevant
 
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