Hey guys,

I have an 09 Fit now at ~300,000kms.

Winter is still going here in Canada and I found out a few days ago that my heater only seems to work when my engine is not idle. If it's idle, then it is blowing cold air. Revving the engine to 3000rpm for a couple of seconds while the engine is already hot (the temperature indicator in the dash being off), then hot air is coming out from the vents.

I read a bit about this and some people suggest looking at the coolant levels. When the engine was cold, I looked at the overflow reservoir and it was between MIN and MAX; this is fine. If I pop the lid on the radiator however, I see no coolant. I can see traces of coolant inside the cap, but I don't see any liquid. Unless am I incorrect, I believe I should see coolant at the top of the radiator. I believe this might cause the cold air when idling issue.

2 weeks ago, I had an engine issue (spark plugs and coils) and I had to get the car to the local garage (not dealer). I know that they replaced the Intake Manifold Gasket. When I got the car back, I noticed on my bill that I was charged a small amount of coolant. I don't know what kind of coolant they put in it. Last time I did a coolant change, I used Honda 50/50 blue. The coolant in the overflow looks blue, but they might have mixed with another type of coolant than the Honda one. I believe they might have not add enough coolant to the radiator, which is causing the cold air in idle. Or I have a leak somewhere in the system (possible due to the new Intake Manifold Gasket?).

I have a jug of Honda 50/50 blue coolant; should I simply top it off ? What is the correct procedure for this ?

Your thoughts on this ?

I need to keep the Fit for another 3-4 months; my Subaru Crosstrek order is already placed and waiting for delivery. I just need to get the little Fit to work until then.

Thanks,

Neo.

 

Yeah, sounds like air in the coolant system, probably getting trapped in the heater core.