Timing belt change, 15 Golf

[Brian's96TDIPASSAT]

I just recently did the timing belt, waterpump etc. on my 15 Golf. Drove a day about 75 miles, everything perfect. They next day on the highway check eng light came on, had a code P2456, DPF pressure sensor. Sensor 1 melted, melted the connector. VW took care if it under the warranty extension but doing some research it's not the first case of this happening.

 

[demagxc]

I encountered almost the exact same scenario. Roughly around the same mileage from completing my timing belt myself, there was a burning plastic smell and magic smoke coming from under the hood around the DPF. I dont remember the codes, but they were associated with DPF and exhaust pressure and temperature. VW covered the replacement sensors and wiring under the warranty as well.

It would be good to know if this was just a coincidence or the result of missing a critical step in completing the timing belt swap.

 

[Brian's96TDIPASSAT]

I encountered almost the exact same scenario. Roughly around the same mileage from completing my timing belt myself, there was a burning plastic smell and magic smoke coming from under the hood around the DPF. I dont remember the codes, but they were associated with DPF and exhaust pressure and temperature. VW covered the replacement sensors and wiring under the warranty as well.

It would be good to know if this was just a coincidence or the result of missing a critical step in completing the timing belt swap.

I don't see it as a coincidence and I did it right with all the right tools, procedures so I"m baffled. We are not the only two people this has happened to.

 

[adjat84th]

Common problem, either age or emissions fix causing even higher heat under the hood right above the DPF. They're inexpensive and easy to replace as long as the hoses are still good.

 

[Brian's96TDIPASSAT]

Common problem, either age or emissions fix causing even higher heat under the hood right above the DPF. They're inexpensive and easy to replace as long as the hoses are still good.

One of my two sensors completely melted, connector to that sensor and hose had molten plastic on it. I was talking with the tech in his bay and he got it as a whole assembly, hoses, both sensors and mount/cover with a pig-tail. Leads me to believe it happens more often then people think

 

[740GLE]

under a working system there is no flow through the sensor, it's similar to a O2 sensor. My only guess is that by moving the sensor the hoses/connection is causing a crack, just enough that blow by and exhaust gases flow through the sensor causing melting.

 

[Brian's96TDIPASSAT]

One good thing about doing the belt,,,,,,gained about 2mpg and the engine comes to a nice idle much quicker than before. I did do the air filter and fuel filter as well but the air filter was relatively clean.

 

[Cuzoe]

Anybody in SoCal want to do my belt, or have a shop recommendation? Mine is due about now, for calendar time more-so than miles. I'm somewhere around 50k but original belt. It was a stop sell car so no miles until 2017, but still... feeling like it's time and I'm entirely un-interested in doing it myself, haha.

 

[dataiv]

I just recently did the timing belt, waterpump etc. on my 15 Golf. Drove a day about 75 miles, everything perfect. They next day on the highway check eng light came on, had a code P2456, DPF pressure sensor. Sensor 1 melted, melted the connector. VW took care if it under the warranty extension but doing some research it's not the first case of this happening.

What instructions / manual did you follow? The official service manual or something else?

 

[Brian's96TDIPASSAT]

I just had found the torque specs, the rest is kinda self explanatory if you've done them before, buy the correct tool set and let er rip

 

[pedroYUL]

Reading this thread and some others, it is still not clear to me what exactly fails.

Sounds to me that it has to be the sensor failing and melting miserably (what a crappy failure mode), as others just change the sensor adapt it and be on their merry way.

What did VW say to you Brian when they fix it, just the sensor and connector, or some other parts needed?

Also, was the repair covered under dieselgate warranty?

 

[demagxc]

Reading this thread and some others, it is still not clear to me what exactly fails.

Sounds to me that it has to be the sensor failing and melting miserably (what a crappy failure mode), as others just change the sensor adapt it and be on their merry way.

What did VW say to you Brian when they fix it, just the sensor and connector, or some other parts needed?

Also, was the repair covered under dieselgate warranty?

When this happened with my car, it was covered under the dieselgate warranty. The dealership did not provide any insight into why the sensor failed. After the repair was approved by VW, the dealership mentioned that it must be a common problem because VW was sending them a "repair kit" with all of the required replacement parts included.

 

[dataiv]

Does anyone have the engine service manual (specifically that would cover the timing belt change, etc.)? I stupidly signed up for a day for the Erwin system and grabbed the sections I needed for my vehicle, but I got the gas engine manual not the one for the 2015 diesel EA288 / CRUA. If anyone has that portion of the service manual, I would much appreciate a PM. Thanks!

 

[Brian's96TDIPASSAT]

Reading this thread and some others, it is still not clear to me what exactly fails.

Sounds to me that it has to be the sensor failing and melting miserably (what a crappy failure mode), as others just change the sensor adapt it and be on their merry way.

What did VW say to you Brian when they fix it, just the sensor and connector, or some other parts needed?

Also, was the repair covered under dieselgate warranty?

It was covered by dieselgate warranty. Came as a kit, the dealer I brought it to had no clue about it happening. I spoke to another dealer and the tech said it happened to him after replacing a belt on a 15 golf as well.

 

[pedroYUL]

It was covered by dieselgate warranty. Came as a kit, the dealer I brought it to had no clue about it happening. I spoke to another dealer and the tech said it happened to him after replacing a belt on a 15 golf as well.

Thank you and demagxc for the info. Since our cars are not the first ones with DPF, I would think that people with MKV and MKVI cars should've seen much more cases like this.

I still fail to see the correlation with the timing belt change. It's kinda baffling.

 

[RIP TDI]

I still fail to see the correlation with the timing belt change. It's kinda baffling.

One possibility: extreme high heat cycles over time render the sensors physically brittle. When disturbed (even lightly and indirectly) during a TB change, a crack forms and that's all she wrote.