VW Virtus Coolant Leak & Overheating Needs Expert Fix

Had a similar situation with a 2016 VW Polo TSI. The symptoms matched exactly, engine overheating, coolant leaks, and persistent check engine light. Initial diagnostic trouble code readings suggested a control unit issue, but it turned out to be more serious. The root cause was a wiring issue between the coolant temperature sensor and the engine control unit. The CAN bus signals were inconsistent, making the system think the engine was running cooler than actual temperature. This caused incorrect coolant flow management and eventual overheating. The repair required: Complete testing of the sensor wiring harness, Replacement of corroded connector pins, Recalibration of the temperature sensor, Clearing fault codes from the control unit The coolant leaks were actually from a cracked reservoir that failed due to repeated overheating cycles. This needed replacement along with a full cooling system flush. This was definitely a serious issue that could have led to engine failure if left unaddressed. Based on your symptoms, recommend getting a proper diagnostic scan and having the wiring connections thoroughly checked before assuming its just a software glitch.

Thanks for sharing this detailed feedback. It sounds very similar to what I am experiencing with my Virtus. The communication fault between sensors and control unit seems to be a common issue in these models. I am planning to take it to a specialized workshop next week for a full diagnosis. Did you end up having any other problems after the repair was completed? And could you share how much the total fix cost you in the end? Knowing if this was a permanent solution would really help me prepare for what is ahead.

After the initial repair work, I can confirm the control module communication error was completely resolved. The specialized workshop did thorough car diagnostics and found it was mainly a connectivity issue with damaged wiring. The fix was straightforward, they repaired the faulty cable connection to the component for 95€. Since that repair six months ago, the temperature readings have been stable and accurate. No more coolant leaks or check engine lights. The diagnostic trouble code hasnt reappeared either, which confirms it was indeed a wiring problem rather than a more serious issue. Key point, once the proper diagnosis was done and the actual problem fixed, no other related issues came up. The initial symptoms you described match my experience exactly, so hopefully you will have similar success with a relatively simple fix. Just make sure they perform a complete diagnostic scan to verify the communication fault is fully resolved after the repair.

Found a VW specialist workshop that really knew their stuff. They ran a complete car diagnostics session and found the exact same wiring problem you mentioned. The communication fault between the temperature sensor and control unit was causing all those overheating issues. Total repair came to 280€: Diagnostic testing: 60€, Wiring harness repair: 95€, New coolant reservoir: 85€, System flush and refill: 40€ Been about 3 weeks since the fix and the car runs perfectly now. No more check engine lights or coolant leaks. The temperature gauge stays steady even on longer drives. Such a relief to have it properly diagnosed and fixed after my frustrating experience with the first mechanic. Thanks again for pointing me in the right direction about the connectivity issue. Saved me from potentially much bigger problems down the road.