A miriad of problems (Ad Blue, CEL, no heat, temperature gauge)

[syd.fos123]

Not sure if any of this is related, but I’ll just list the past week of my 2014 Passat TDI SEL (164000 miles):

About a week ago, I had a message saying my AdBlue levels were low and that engine start would not be possible in 200 miles (this is odd, as I normally fill the AdBlue when it tells me at 1500 miles, and I had not received this message). So I fill up on BlueDEF and the signal stays on for 3 days before turning itself off before I get it to the mechanic, and they are not able to recreate the code.

Flash forward to today, where Im on the road and I look down to see that my CEL has come on, and I also note that I have no heat. The code is P2457 and then the same code with “pd” next to it. Car temperature is fine, and Im able to clear the code and it has yet to come back on.

Aside from all of this, my temperature gauge normally sits at 190, but occasionally will go up to as far as 210, especially when I am going up steep hills. I never get an indication that the engine is overheating, and it always returns to the 190 mark.

On top of this, it seems that the fan on my car stays on after I drive anywhere for roughly 5 minutes before turning off. Im aware the fan running after some trips is normal, as it could be a regen cycle, but it has gone from once every few trips to every single trip (even just a few miles).

I am not sure if any of these things are related, and the car was recently serviced for a coolant flush/new water pump and a new timing belt (maintenance, not broken). If anyone has any thoughts, they would be appreciated. Thanks in advance!

 

[Tom in PT]

No heat -> probably a clogged heater core. Excessive regenerations will cook G13 coolant and lead to clogs forming in the heater core. Overheating is not normal. It could be several possible things including air in the cooling system, clogs in the cooling system, water pump defective, etc. The 200 mile to no start message often comes up when there is a problem with too many short trips preventing the DPF from being thoroughly cleaned during a regen cycle. I would start with replacing the heater core, flush the cooling system thoroughly at least three times to get any remaining debris out of the system, refill with G12+ coolant, purge all air, and then, if the car is not overheating anymore, tune the car. I had many of these symptoms a year ago in my '13 (except overheating) and a Kerma tune solved my issues.

 

[06bluebeetletdi]

The 200 mile until no start could be the ad blue injector, mine went from a check engine light to 200 miles to no start in about 20 miles because of the injector.
no heat probably a clogged heater core, fans running after you shut the car off is probably flaky coolant remains clogging something, mine was the oil cooler. The car ran the fans every time you turned the car off if it was over 72* for about 5 years, after replacing the oil filter housing last year, the fans turn off when i turn off the car even if it’s over 95*. Mine is a 14 sel premium with 133,000 miles.

 

[syd.fos123]

Thanks for the advice everyone, looks like its the heater core and temperature sensor. Too bad Im out of the warranty , Ill keep this thread updated if anything else pops up!

 

[drew_t]

the car was recently serviced for a coolant flush/new water pump and a new timing belt (maintenance, not broken)

Define “recently.”

Does it literally give you no heat at all, or just less on the passenger side than the driver side? (And, just out of curiosity, why are you looking for heat in Georgia this time of year? Or did something else lead you to check it?)

 

[syd.fos123]

Define “recently.”

Does it literally give you no heat at all, or just less on the passenger side than the driver side? (And, just out of curiosity, why are you looking for heat in Georgia this time of year? Or did something else lead you to check it?)

Flush and timing belt were done roughly 4 weeks ago (or about 2,000 miles). And we had a chilly morning yesterday, so I just wanted to warm the car a little. I noted no heat on both passenger and driver side. To add to this story, on my way home yesterday, I thought I would try the heat again just to check, and was met with about 15 seconds of hot air before it turned cool again. About 5 minutes after that my engine temperature very quickly started climbing, reaching 230 before I was able to get off the road and turn off the engine. The car was dropped off at the mechanic, who today suggested the heater core and temperature sensor replacement, as well as another flush of the entire system to remove any potential clogs.