3 replies to this topic

[maccers]

Hi All, changed coolant last week, but noticed heater starts off blowing hot air, then starts to blow cold air, when the tap is on the "heat" position.

I have done the following: All with engine fully warmed up and thermostat open, heater tap pushed in "hot" position

- Bled the heater return pipe at the bottom hose side in engine
- Bled the heater return outlet on the matrix from within the car

I have tried with the rad cap on, and with the rad cap off, as above both with system fully warm.

In both cases the water does not flow out, under under pressure until a increase the engine rpm, then it runs out, but again not under any real pressure.

I'd expect it to literally p*ss out, especially with cap on and system warm, under full pressure.

Any ideas? Typical now we are getting into colder days I manage to knacker the warm air!

Richard.

[irish.yobbo]

Hi Richard,

I've never tried bleeding the system with the pipes actually off. I bled the heater just the other day, since I was attaching a water heated manifold, and I was using the heater pipes. I just cut the pipe and attached the manifold.

Since there was an obvious airlock after this, I just started the engine up with the radiator cap off, and waited for the water level to drop when the air escapes. Filled it back up and it's been working fine (both the engine and the heater).

[mikey72]

I just changed my thermostat, flushed the system etc, and the thing I found was the tube off the bottom hose, where the heater hose comes out of was 90% blocked with rust. I had to stick a screwdriver down to clean it all out, and flush the pipe through off the car.
Never had any problem filling up though, just topped up and ran the engine, and topped up again.

[maccers]

I'll try that, I must say there was an awful lot of what looked like rusty bits came out of the heater matrix that I tried oh so hard to catch in an ice cream tub! (empty one...)

I'll have a look at that, maybe the rad flush loosened up so much of it.

Ta.