Hi, very helpful of you to share this information. I’m facing a similar issue with my 2007 city since the start of this winter season. A choked heater is also what I suspect to be the culprit.
Did you try flushing the heater core specifically, rather than the whole cooling system? Kindly share how, if u did try; Cleaning agent used etc. Any online references will also be very helpful. I’m really creeped by the thought of getting the whole dash off so really want to try something else before resorting to this.
I’ve tried flushing once but without any cleaning agent. Simply flushed using the normal tap water pressure (done by my mechanic). It wasn’t successful. I’m told that City’s heater core is made of Aluminium so rinsing with acid (which is commonly used by the mechanics for the purpose) is not safe and can lead to core leakage. Apparently it was already done once on my car 4/5 years ago for the same issue so the mechanic is not ready to do it again (didn’t personally handle it then, supervised by our driver).
Now I’m planning to do a combination of some of the following:
1- Use a cleaning agent (a radiator flush probably, also have read abt dishwashing detergent to be used for the same) to soak in the core.
2- Use pressurised water to flush (not over the limit, I understand the system can’t withstand more than a certain limit).
3- Use pressurised Air like above.
4- Use hot water to soak.
Pls comment and/or share you own findings. Also share more pictures, esp of the core. Was it really badly choked?
