Heater Fail

Dollywobbler · Post by **Dollywobbler** » Fri Dec 24, 2010 5:43 pm

Not a good start to Christmas. Jumped into the BX, fired it up (queue loads of smoke and misfiring - brand new glow plugs haven't cured that but it was many degrees below zero) and I started scraping the windows. After a few minutes of running, top hose was warm but heater outrput was freezing. Tried going for a drive but still absolutely no heater output. Tap is open so what's gone wrong? Coolant is still liquid and it worked yesterday!

Have noticed the heater getting cooler at times, but while the 'stat is a suspect, I wouldn't expect it to cause a complete failure to warm up even a little bit.

Had to ditch the BX and coax the 2cv into the snow, despite that having its own issues!

toddao · Post by **toddao** » Fri Dec 24, 2010 6:54 pm

I'll wager that the heater matrix is frozen solid. Not enough anti-freeze in the coolant. Something similar happened to me a couple of years ago. It was a combination of the 'door' to the heater matrix freezing shut and the matrix itself being frozen up. It took approx 40 minutes of driving and repeated opening/shutting of the on/off heater control to free it up and let the warmer coolant in to the system. It was quite alarming with an infant in the car too. I now run -30 degree coolant un-diluted.

p.s it can't be the thermostat if the top hose is warming up and some coolant will still be liquid even though some of it is frozen in the matrix

Post by **mat_fenwick** » Fri Dec 24, 2010 9:16 pm

I'd be wary about running (ethylene glycol) coolant undiluted - it relys on the mixing with water to lower the freezing point of the resulting mixture, with the lowest freezing point at something like 30% water. Neat ethylene glycol will freeze at about -5 degrees C!

Sorry, can't shed any light on the original problem but would agree that whatever happens to the thermostat, coolant *should* still circulate through the matrix.

toddao · Post by **toddao** » Fri Dec 24, 2010 9:59 pm

It comes in a nice blue bottle here and is pre-mixed for -30 ready for use. Not only does it look good it tastes bloody lovely. Cheers!

Post by **Defender110** » Fri Dec 24, 2010 10:08 pm

Yes ready mixed coolant is becoming increasingly popular over here too, it includes water conditioners in de-ionised water I believe.

http://answers.halfords.com/answers/402 ... htm?page=2

http://www.nielsencdg.co.uk/acatalog/Co ... olant.html

Post by **mat_fenwick** » Fri Dec 24, 2010 10:10 pm

toddao wrote:It comes in a nice blue bottle here and is pre-mixed for -30 ready for use. Not only does it look good it tastes bloody lovely. Cheers!

Ahhhh! I understand now.

Not for me though, I prefer the stuff in green glass bottles...

Linegeist · Post by **Linegeist** » Sat Dec 25, 2010 8:01 am

Gosh Mat! I never thought of you as a gin man!!!!

Dollywobbler · Post by **Dollywobbler** » Sat Dec 25, 2010 10:34 am

Frozen matrix would fit the bill. I couldn't operate the tap - though on mine, there's a rather heath robinson affair to replace the original broken cable! It was ferociously cold that night. Will have to see if it thaws out...

Mike E (uk) · Post by **Mike E (uk)** » Sat Dec 25, 2010 10:53 pm

A good reason not to use 100% antifreeze, is that it is useless at moving heat. You need some water mixed in for that.

It may not freeze, but it will overheat the car when the weather improves.

Mike

kiwi · Post by **kiwi** » Sun Dec 26, 2010 3:12 am

50% antifreeze is about as good as it gets in my eyes! Like has been said to much is not good when the engine warms up.

Dollywobbler · Post by **Dollywobbler** » Mon Dec 27, 2010 6:12 pm

Back home now, and a bit of a thaw is due, so I'll see if the heater recovers...

It's still running pretty much on the coolant it had on the BXagon - which was a pretty strong mix (albeit with some accidental detergent in it - improved the heater performance though!). Certainly, the coolant didn't freeze up the way that the CX did a few weeks ago...(that thankfully thawed itself with no damage done and now has a stronger mix!)

kiwi · Post by **kiwi** » Tue Dec 28, 2010 12:09 am

You thought that the heater tap could be stuck with gunk like they like to do?

You have not mentioned this so maybe or maybe not you looked into that.

Dollywobbler · Post by **Dollywobbler** » Tue Dec 28, 2010 3:46 pm

Tap's open. Started the car today and the heater was fine, so a frozen matrix looks likely. Coolant level was a little lower than usual, so I'm worried I've now got a leak somewhere. Indeed, after a couple of minutes, there was some steam from down the back of the engine...

Bit miffed about the starting. Having changed the glow plugs, it's no different to how it was before, even with multiple bursts. Still get lots of smoke and misfiring. Horrible. Not quite as bad with today's above-freezing conditions!

Jaba · Post by **Jaba** » Tue Dec 28, 2010 6:01 pm

New glowplugs do not necessarily mean that they are all fully functional.

How do I know this ???

Post by **mat_fenwick** » Tue Dec 28, 2010 6:44 pm

Air leak Ian? Can't remember if it was discussed/checked previously but I had one which took a while to track down. Starter still turning OK I hope though!