incrementalg

A couple of weeks ago the check engine light came on, so I decided to schedule an appt to have it checked (along with some other minor items)
Dealer says cel was result of bad thermostat and car was running too cool as a result. They replaced under warranty. (not an easy job)
I pick up the car and the cel comes back on about 100 feet out of the dealer lot. I get pissed quick and take it back. The service manager takes it back and says it was a bogus code related to cam tension. Manager says they recalibrated and it's all set. (WTF does that mean?)
I leave the lot and the cel light comes on about 1/2 mile down the road!!!! Dealer is closed now, so I risk the drive home. (not knowing if it is something severe due to the removal of belts to get to the thermostat)
I take the car back to the dealer and tell them to get it right and not to call me until it's done and they've road tested.
After almost a full day, they finally call and say it's the cam sensor and they need to order a new one. It's been 8 days and they still have the ar. They claim the part,which was supposed to be overnighted, hasn't arrived yet.

I'm now doubting their diagnosis given the sudden and surprise failure of the cam sensor.

Am I paranoid in thinking they either f'd up my car and haven't told me, or they don't know what the hell is wrong with it?

The series of failures causing the cel seems unlikely to me. (thermostat, 1st cam issue, then cam sensor)

samm

Was your coolant temp low on the gauge? Sounds like another crappy dealer.

drivingforever

I've heard a lot of "failed thermostat" stories lately due to the cold weather, and I've never heard of the check engine light coming on due to that. In fact, because the amount of load can vary quite a bit at every start-up cycle and each day brings a different ambient temperature, I don't know how it could predict that the thermostat was failing open. (Failing closed would result in overheating, and THEN it would throw a code.)

More likely is that the coolant temperature sensor went kerflooey. They're a known failure part. When I brought my allroad to Continental Motors in Naperville, IL due to it stalling after a warm start in Michigan, they replaced that sensor for free, citing that it was a "warranty issue." To the sensor it would appear like the engine was running cool, but turning on the heater would prove otherwise.

Both the coolant temp gauge and engine computer use the same sensor, but there are independent circuits for each in the same package. The gauge may report correctly, but the engine computer will never see it.

Find a dealer that's not inept.

incrementalg

Could both the cam sensor and temp related check engine lights be due to an electrical/circuit issue?

autosolutions

& the belt was off to get to the thermostat.

autosolutions

Performance malfunction in cooling system. This is a common code with the 2.0l VW motors & a thermostat gets it every time. The car is smart enough to know if it has been operating for a certain period of time regardless of outside temp the engine should have reached operating temp.