Coolant loss? Changing heater control valve tricky? 940
 

Hi guys,

Recently bought a 1994 940 without aircon, and discovered the drivers footwell is soggy with coolant :lightning: When I bought the car I noticed the coolant was low, but didn't think anything of it stupidly, there were no visible signs of headgasket gone, and footwells seemed ok - I thought the drivers footwell was just rainwater from feet because we went to see it when it was pouring down with rain. The heaters worked fine too.

At first I thought it was the heater matrix, but it seems as if only the drivers side is wet. I thought I could feel a tiny bit of damp at the passenger side too but my mind might just be playing tricks on me.

It is certainly crusty around the heater control valve, but when I left the car running for a good 45 mins with the heating on turning it up and down a couple of times I could see no drip or feel anything from that area :err: Does it only come out after long journeys? (in fact that is probably a daft question - guess it depends on how knackered it is!)

Anyway I have found a bosch replacement on euro car parts for £30ish so I will start by doing that. Is it a tricky job guys? I read that it is awkward and it is best to remove the clutch pedal, anyone know how to do this? I couldn't find a guide for the replacement of the valve either so if anyone has any tips that would be brill.

I'm particularly concerned about how to plug the hose that comes through the firewall back into the new valve...




If the matrix was leaking too, would both footwells definately be soggy? Anyone make anything of the pics?


Many thanks in advance chaps :thumbs_up:

Hi,

In non air-con car it is more likely to be the heater control valve. And as you have found out they don't cost much to replace so it would be a no-brainer to change it anyway..

It is more likely to start leaking or seeping on a drive so on tick-over for x hours will likely tell you very little..

Heater core can and will flood both sides as the coolant is leaking from behind the air distribution box so can, from there, go anywhere..

Des. . . ;)

Cheers Des,

Will get that changed as soon as i'm confident enough to do it haha, any tips on changing it?

Many thanks!

Hi,

The FAQ is a good place to start.
FAQ: Heater Control Replacement...

If a manual, removing the clutch pedal is handy I have heard.

Des. . . ;)

Cheers Des, hadn't come across that before :thumbs_up:

Looks like it's just the valve, my one did the same. If you take the clutch pedal out it's much easier to do the job. You need to drain all the coolant to do it easily as you really need dry grease free pipes to get a good seal.

If you suspect the matrix you can just about get it out with the clutch pedal removed. If it has gone as well you might find dampness inside the heater outlets which apart from the rear vents is the lowest point of the heater box.

It might be worth thinking about changing the flexible pipes from the valve to the matrix just in case as well.

Thanks guys,

How do I go about draining all the coolant? Is there a plug at the bottom of the radiator?

Also the pipes to the matrix, are they difficult to replace/possible to reach? Doesn't look like there is much room there!

Anyway I ordered the valve, £31 delivered from euro car parts, not too bad, but still bites slightly when I wasn't told about the issue - still chasing the seller up!

Fingers crossed I will get it this week, so next weekend I can change it :)


Cheers,

Yoda960

Hi,

You should find there is a drain plug on the engine not far from the oil filter.
Not dissimilar to a household heating drain point. Loosen with a spanner and pop a hose on the plug to direct the coolant into a container.

As for the pipes, They are likely to be well attached to the metal by now and will likely need cutting to get them off.

Des. . . ;)

I think my 740 might be affected by this aswell.

I have coolant loss and damp carpets. Strange thing is damp carpets don't look anti-freezy like yours do. I have noticed coolant on the anti-roll bar aswell though, so maybe it's water pump.... maybe it's both??

Anyway, the reason I post... reading that FAQ it says the Heater-only cars is passenger side... so how will removing the clutch pedal help?

Hi,
'Cause american passengers actually sit in drivers seat?? :D

Des. . . ;)