W124 Heating 'squelching' noise

[W124-300TE-1989]

Hello All
Feeling a little over-awed at the technical expertise on show on this site, so forgive me if this sounds daft!
The heating in my 1989 W124 300TE has started to make a peculiar squelching noise every five seconds or so - as if there is water in there somewhere. Has anyone else ever experienced this? Am I going to have to take the fascia off to have a look in order to fix it? Is it a major problem or can I just add it to the list of idiosynchracies of an eighteen year old car??
Thanks
MK

 

[Richard Moakes]

Its probably nothing more than a bit of air in the heating matrix, nothing too much to worry about. The 'squelching' happens every time the duovalve opens and allows some hot water into the matrix.

I have flushed it out of mine by turning both temperature controls to maximum, turn the fan up and let the valves open fully. Go for a short drive with the windows open so you don't cook and there is a fair chance the air will be flushed out for you.

Cheers,

 

[W124-300TE-1989]

Wow - thanks for the prompt reply Richard!
That sounds very reassuring - I'll give it a go.
Best,
MK

 

[MW]

Replaced a radiator recently, and we had a short sqelching sound after too, behind the passenger glove box. Not every 5 seconds but occasionally. It went away after a week or so. Almost certaintly air. If you have no fluid loss, I agree open up the heater to max, get it hot, and give it a belt. After it has half cooled down, release the pressure from the rad cap carefully, and squeeze the water pipes. May need to do it twice, but it should dissappear.
Removing the dash is a nightmare.

 

[MW]

Sorry, ours is a W124 as well. A 2.3 litre

 

[MW]

Sorry again, our car is much newer.... at 17 1/2 years old!