Cam Gear - How Critical of a Repair?

[jmciii]

I am the new owner of a 2002 EV Weekender. Previous owner had the timing chain kit redone in June 2018 at 117K miles. It was reputable shop and I spoke to them this morning.

I bought the vehicle knowing about some CEL codes related to the position sensors per the seller. So this isn't a surprise. I pulled the codes last night:

P0340
Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)

17748
Camshaft Position Sensor/Crankshaft Position Sensor Incorrect Allocation - no indication on display

16725
Camshaft Position Sensor Circuit Range / Performance - no indication on display

The shop said that they tried to sell the previous owner on replacing the cam gear in addition to all of the chain kit work they did. At ~$700 the shop said that he did not want to add that part to the work. I'm looking at the labor cost line item on the invoice and it's hard to stomach as the new owner. He decided to chance it, I am sure, knowing that he would sell the vehicle in due time.

So, the vehicle runs great so far. The shop that did the work tells me that the gear is an efficiency/performance matter and not a critical component that will leave my family stranded in the woods.

My working idea is to let this go for awhile as I get more accustomed to the vehicle. If I am going to have something as invasive done again I want to make sure there are no other gotchas. Is this a sound approach?

Is it true that the cam gear is an efficiency/performance matter and won't leave me broken down?

I realize efficiency/performance can have broader affects on an engine system over time. But, I am seeking confidence in taking this thing on some near term trips before I have someone go back in. I'd like to do a few trips as-is: 3-hours to fish; 10-hours to the beach; 5 hours to the mountains over the next ~6 months before I get into this.

Thanks for any perspective. This forum is great and I hope to add some value as I get to know this vehicle.

[jmciii]

I had a different shop in my city just call me back and said that they have never seen a cam gear go wrong. (I bought vehicle in another city about 1 1/4 hours away.)

They theorize, without seeing the vehicle, that the previous shop got a tooth out of time and, rather than correct that issue, suggested the cam gear. That doesn't fit the story they told me about trying to sell the gear when they got into the kit. But I wasn't there so who knows. (I will see if I can get the previous owner to corroborate the cam gear pitch.)

Either way, I've got to decide if I'm comfortable with this issue in/around a notorious timing chain that was supposed to have been addressed a little over a year ago.

[jmciii]

I am rekindling this conversation with myself in case anyone wants to contribute or ask questions about my experience. My invoice from the timing chain repair is here:

_________________
-John
2002 EV MV Weekender Westfalia

[Stripped66]

The invoice says the intermediate gear was replaced.

The intermediate gear is the gear that is known to go bad. There are 4 other gears associated with the timing chains: 2 cam gears, the inner gear on the intermediate shaft, and the timing gear on the crankshaft. None of these are known to fail prematurely. The outer gear on the intermediate shaft is the one that is known to be problematic...and the invoice suggests that gear was replaced.

Any discussion with the shop about replacing the cam gears is probably confusing the situation. The cam gears are not a known issue, and they wouldn't usually replace them. This confusion is further supported by the fact they discussed the cam gears as an efficiency/performance matter: it is not uncommon to replace the stock cam gear with an adjustable cam gear as a way to tune the engine for performance. (This is not something you would bother with on a Eurovan. It is something you might bother with on a Cayenne. It is something lots of folks bother with on GTI's.)


By your own admission, the vehicle runs great. It would not run great if either of the cams were off by a tooth.
_________________

[ocelotpotpie]

I commented in a another thread, but in short:

Get a proper VW scan tool or visit a shop that has one.

I wouldn't trust a shop that pulls up generic OBDII codes if they claim to be reputable with these vehicles. You really need the level of detail that the proper tool such as VCDS brings.

Your codes seem to be camshaft related but you aren't throwing any misfire codes, so I'm guessing it's not the intermediary gear or timing chain guides.

You could have a sensor failure or a wiring issue. Or it could be something else. A proper scan will get you a LOT closer to the area of where you should be looking.

[Zeitgeist 13]

I guess I should add that I've been throwing those same codes ever since I replaced the timing chains/rails, about 8k miles ago. I've learned to live with it. The engine runs excellent and has no performance issues whatsoever. I pulled the head, hand lapped the valves and replaced the stem seals at the time. No sludge or varnish build up, and the intermediate gear was excellent. These are tough engines.

I too got worked up into a lather about timing chains and transmission issues after I bought this van, but as I've gotten acquainted with it, the anxiety fades. Someday I'll dive back in and check the cam sensors and wiring
_________________
Casey--

'89 Bluestar ALH
'01 Weekender --> full camper
NEAT, no ICE.

[jmciii]

Thanks for this. I will likely have the more advanced codes read as you all advise. Beyond replacing both the cam sensors as I have done, I am not experienced enough to doing anything else in this area of the vehicle on my own. And, I find the dialog with this Porsche specialty shop that was used annoying at its best.

I am probably most relieved by you having the same codes post-chain work, Zeitgeist 13.

-John
_________________
-John
2002 EV MV Weekender Westfalia

[ocelotpotpie]

[mvaska]

the screen filter for oil supply port to cams is known to break and get snagged inside the VVT cam. i always remove this screen when doing chains and also really really clean out the cams, ensuring that they easily have full range of movement. If one cam can't move the full range you'd get these errors and it wouldn't necessarily run terrible.

[Zeitgeist 13]

[quote="ocelotpotpie"]