Hi, my wifes 2006 Fabia 1.2 was not blowing hot air through the heaters. I put in some coolant flush stuff mixed with water hoping to clear out any blockages, it said on the bottle to leave overflow filler cap off, run car for 15 mins at fast idle until the radiator fan comes on, i tried this but the water/coolant flush mix started to boil over before the radiator fan kicked in. I didn't want to risk any damage so I stopped, The temp gauge in the car stayed at 90 throughout even though this cant be true as the water was boiling. Does anyone know if there may be a problem or should I have kept running and waited for the fan to kick in?

Were you putting fresh  neat coolant in the top and a pipe attatched to return to clear out old? , thats the best way to get rid of air locks? It boils because not under pressure . Coolant needs fully changing every 4 years .More likely you have air in the system than any blockage unless no antifreeze in it in which case it will be sludged . A mechanic mate showed me this trick, takes 4 mins to go round the system and no air locks  guaranteed  .   Is it ok now caps back on Ie no boiling 

Edited 2 November, 20169 yr by blueR36

Is there just one radiator fan, or two?

Does the car have air conditioning? If so, does the fan come on at low speed shortly after switching that on? Or does it cycle on (at high speed, noisily) and off again regularly?

 

I'm wondering if your fan has lost its low-speed function, which seems a common fault, and so wouldn't cut in (then at high speed) until coolant was above 100°C. The dash gauge is 'calibrated' to indicate 90 over a range of temperatures to reduce user anxiety, so not really to be trusted entirely to reflect reality.

Hi, thanks for replies. Before I put the flush-stuff/water mix in, I opened up the release valve on the radiator (under car on passenger side) and ran cold water from a hose into the overflow tank for about 15 mins, the coolant was really dirty at first but was running clear after 10 mins. Then I closed the valve and filled with the flush-stuff/water mix, ran fast idle, then panicked at the sight of all the steam! Left it for about an hour, drained the mixture (opened up the release valve). Then filled with 40/60 mix of G12/Water. Still blowing cold! No boiling though.

 

I've had people suggesting blasting the Heater Matrix pipes with a hose, and/or putting a washing powder/water mix in to clean it out. Anyone recommend this?

 

Blue r36 - where do you attach the pipe you mention?

 

Wino, yes it has a/c but no problems with the fan as you described, it has just 1 radiator fan.

Hi, thanks for replies. Before I put the flush-stuff/water mix in, I opened up the release valve on the radiator (under car on passenger side) and ran cold water from a hose into the overflow tank for about 15 mins, the coolant was really dirty at first but was running clear after 10 mins. Then I closed the valve and filled with the flush-stuff/water mix, ran fast idle, then panicked at the sight of all the steam! Left it for about an hour, drained the mixture (opened up the release valve). Then filled with 40/60 mix of G12/Water. Still blowing cold! No boiling though.

 

I've had people suggesting blasting the Heater Matrix pipes with a hose, and/or putting a washing powder/water mix in to clean it out. Anyone recommend this?

 

Blue r36 - where do you attach the pipe you mention?

 

Wino, yes it has a/c but no problems with the fan as you described, it has just 1 radiator fan.

Look at this picture, top pipe removed so you dont do anything to radiatoror , he had a rubber pipe of same dimensions leading to floor , take top off and coolant tank start engine and keep topping up with neat coolant, when you have put 3 bottles in its done, turn off and replace pipe then cap , then start , this gets rid off any air at same time , hope this helps

Edited 2 November, 20169 yr by blueR36

Reverse flushing (just) the matrix is the way to go, assuming you have one hot pipe and one cold at the point where they go into the firewall/bulkhead.

Have a look at this thread from post #33 onwards if you haven't already.

Hi

 

Trust Wino on this one, it is my discussion he linked you through to and my car is still nice and warm after several weeks, mine was the matrix.

 

I only took it to the garage as I would rather let somebody who knows what they are doing get it done, the one area I think may have helped, after flushing, they also use a fine steam pipe to help loosen anything that may have been left behind before flushing again.

 

Cost me about £60, which I felt was fair, even more so now I have a working heater again.

 

Good luck

 

 

Martin