Heater blowing cold air

2001 VOLKSWAGEN GOLF
162,000 MILES • 1.9L • TURBO • 2WD • MANUAL
Avatar
AUBZ44
  • MEMBER
  • 1 POST
Hi, I have a mk4 golf GT tdi pd 130. the heaters are blowing cold air through. I changed the thermostat but not the sensor. I topped up with new coolant. was just wondering if I do a full coolant system flush including the radiator if this will solve the problem?
Dec 6, 2020 at 5:06 PM
Advertisement
Avatar
KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
I suspect this is a blend door actuator issue and not necessarily a coolant issue. It could be a heater core but I would start with the actuator and make sure that is functioning properly first.

Here are guides that will help with this:

https://www.2carpros.com/articles/car-heater-not-working

https://www.2carpros.com/articles/replace-blend-door-motor

Then if the heater core is still an issue, you will not be able to flush it. These are called multipassage units which means if there is a restriction or a blockage it will just find another path and not remove the blockage. If that is the issue then you will have to replace it. However, I doubt that is the cause so let's check this first.

Let me know what questions you have. Thanks
Dec 7, 2020 at 12:31 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.