Hey all,
Grabbed an inexpensive 2015 Jetta TDI just after the holidays last year. It’s got right around 56k miles on it.
Background: It was definitely in an accident involving the front end and passenger front corner. I don't see anything mechanically wrong under the hood so far from that. From the records I’ve got before we picked it up, the heater core and thermostat were changed last August, a couple thousand miles ago at most. There is something going on behind the dash that I need to dig into: with the fan on, the blower is hitting something, the driver’s heated seat doesn’t work, at all (lights on the switch do come on, though), TMPS reset button doesn’t work, and there something else I can’t remember right now.
Problem for this post: it’s overheating. A lot. It runs really well, but with any kind of load on the engine the temps climb high quick. I have found that leaving the overflow cap a little loose help. With the cap tight, it’ll overheat just sitting idling, with it loose the car will at least idle. If you’re driving down a completely flat road, you can idle without it boiling itself, but any hill or rise at all and the temps go up. When the temps get on the higher side, the heater stops blowing warm air (guessing due to air in the system at that point?).
Work so far: I have verified that the fans work, and they do come on during normal operation. I do not know if the shutter assembly works, but I removed it and it made no difference. I have not found a good procedure for testing the electric auxiliary pumps yet, if anyone has that it would be appreciated. I have pulled the radiators and flushed both with fresh water, they appear to flow fine with nothing unexpected coming out of them. They did not appear to leak, either.
Any suggestions for next steps would be appreciated. I’d rather not just start throwing parts at it, but I need to get something moving pretty soon. It’s been sitting in the garage for too long now. Any common issues with these that anyone knows of? I have another 2015 TDI that I bought new in 2017 after the scandal stuff was subsiding, that’s been rock solid for ~53k miles so far.
Thanks!