Difficulty bleeding coolant on mk1

[ben_r1]

Going by the google search this seems to be a pain in the arse problem that attacks everyone.

Car is a 1995 mk1 clio 1.4 RT with the 8v energy lump. Drained coolant, flushed with water, opened radiator bleed screw ( only one in the system ), filled up with coolant until bubble free etc, tightened it, filled to max level, run car on fast idle for 10 minutes and thermostat had opened and fan kicks in and out etc.

Now the car constantly sits on the fan whilst driving and the heaters go ice cold after 10 seconds, theres no bleed screw for heater hoses, both inlet and outlet hoses to matrix are hot to touch, thermostat opens correctly, no leaks etc. Repeated above procedure several times but still no joy. Help!?

 

[Dan519]

tried squeezing the rad hose repeatedly? Any chance that the matrix is blocked? quite common place on a mk1

 

[ben_r1]

Yep pumped the top hose and purged all air out, definately coolant in the hose. Heaters worked perfectly before, any chance draining and flushing blocked it?

Update: temp gauge now constantly moves up and down when driving between a 3rd of the gauge.

 

[Dan519]

got the heater switch on the hot setting on the dash?

I did one last year that had so much crap in the system, the rad was blocked solid. I had the jetwasher nozzle sealed to the rad outlet, and on full blast with nothing going through at all

 

[ben_r1]

Oh dear, yes the heaters on hot.

Looks like i may need to get a jet washer in the heater inlet

 

[Gray]

 

[Vicky.]

Got a jet washer on the inlet to the matrix and disconnected the outlet, after a minute or so fresh water was flowing freely out of the matrix.

Will test drive and report back.

 

[ben_r1]

No good, still knackered

Heaters are nice and hot for about 10 seconds then nothing, and car runs very hot, although the fan now kicks in and out instead of remaining on.

 

[Dan519]

if the heater matrix was like that, the rad will be too

 

[Vicky.]

Meh, runabout mode = drive it til it blows up

 

[ben_r1]

Fault rectified. Air block in the heater matrix.

You can get around this with the following:

Starting from an emptied system with hoses connected up, disconnect the hose from the return of the matrix ( upper one of the two which go into the bulkhead ) from the header tank.

Disconnect small hose on 90 degree bend on top of thermostat. Now fill this hose with coolant until a good flow of coolant comes from the disconnected header tank hose, quickly reattach to header tank. Attach the other hose back to thermostat housing.

Fill and bleed system as standard, lots of water bubbles in the header tank whilst high idling means your efforts have been successful

 

[ben_r1]

Fault back, after a week of perfect heaters this morning it magically started playing up again.

 

[Gandi69]

Know it might sound silly but have you tried blowing down the header tank filler, just to try and force some of the coolant around? Its worked for me in the past