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View Full Version : P16396 just before timing belt change, how to proceed



Nduetime
12-21-2018, 09:16 PM
Iíve had a bit of a coolant leak for too long now and decided it was time to do timing belt and water pump replacement this weekend, now that I have some time off. Driving home from work today to start replacement of TB/WP, Check engine light came on. Vagcom says I threw the the following code:
16396 - Bank 1: Camshaft A (Intake): Advance Setpoint not Reached (Over-Retarded)
Research tells me cam chain tensioner. I had no real noticeable ticking, rough idle or while driving, nothing really that screamed problem aside from the check engine light coming on.
My question is, Iíve dessabled for the TB/WP repair and to have a look at the timing marks. My marks at the crank and the camshaft appear to be on
9867298673
How should I be proceeding, complete the TB/WP replace, button it back up, clear code, then start engine to verify the TB/WP replacement was correct and to see if the code comes back? Is there something I need to do before I finish the TB change that might be affected by cam chain/tensioner if my timing marks are still on? Or do I need to do anything to address the cam chain tensioner before finishing the TB/WP? Just looking for a little direction on how to proceed further.
Thanks for help.

walky_talky20
12-24-2018, 08:03 AM
The code is only for the VVT advance feature. Your mechanical timing looks good.

The VVT problem as it is, is not super critical to fix. You are not really going notice any running issues. It will just throw that code when it tries to do its emissions cam-advance thing and the tensioner fails to do the full advance quickly enough (or at all). Its not a necessary function for the engine to run properly. I ran mine for a year completely unplugged (VVT feature entirely disabled). That said, these VVT codes are often a precursor to a rattley, clanky tensioner. The best and proper solution will probably be to replace it. Because replacement requires removal of at least one camshaft, it would be ideal for you to replace it during your t-belt service.

There are a few other things you could try:
- Test or replace just the VVT solenoid. This is the electrical part that actuates the advance and can be swapped without even removing the valve cover.
- The solenoid is a simple 12v+, on or off affair. No duty cycle fanciness. So pretty easy to bench test it. Not a super common failure, though.
- Inspect and/or replace the tensioner "feet" (guides). This can help keep better overall tension on the chain. These are a wear item.

Side note:
- If the car has over say...150k miles, I'd recommend replacing the Cam Chain while you're in there. Around 200k is when they start to get stretched out enough that even a good tensioner can't keep the chain under control. It can start slapping the head and the valve cover. Not a rule of course, it depends on service history and other things.
- Replacement of the cam chain requires removal of the tensioner, plus removal of the 2nd camshaft. So again, best to do it all at once. The chain is pretty cheap, like $30 as I recall.

Blazius
12-24-2018, 09:04 AM
Sometimes they bundle chain with tensioner too. You can code out the VVT with ecu reflash if you dont want it. Pretty sure the solenoid messed up.