Sticky Gunge on the inside of the widscreen

**tsam19** · 13-06-2009,03:09 PM

After driving the car for a while the inside of the windscreen becomes spattered with like an oily based substance when I've had the blower heater on.

Anyone know what this is & what causes it & possibly the cure ?

**Crasher** · 13-06-2009,03:53 PM

Your heater matrix has failed and is blowing antifreeze out of the screen vents and it may burst at any time, blowing boiling coolant all over your feet and legs, even out of the vents and into your face-I have seen it happen a number of times when the engine overheats. This also means that you are inhaling antifreeze which may be harmful to your health.

**tsam19** · 13-06-2009,04:34 PM

Heater matrix failure ?

What causes that to happen ?

Whats the cure, some sort of flushing fluid or a new matrix ?

I presume the only symptoms of the matrix failing is this sticky stuff on the inside of the windscreen ?

**Crasher** · 13-06-2009,04:44 PM

The cause is age and occasionally excess cooling system pressure such as from overheating or head gasket failure.

The cure is a new matrix which is a hell of a job as the dashboard has to come out and is even worse if the car has air conditioning as this has to be degassed and re-gassed.

Other than the sticky deposits you may notice an odd curry like odour and misting.

**tsam19** · 13-06-2009,05:19 PM

Yes the 'odd' curry smell is there

I presume that smell will disappear when the matrix is changed ?

Theres no air con though.

**Crasher** · 13-06-2009,05:27 PM

Yes the smell will go. I strongly recommend you only buy a genuine VW dealer supplied matrix. These are horribly expensive at £116 plus you have to buy the foam strips separately BUT they are covered by a 2 year parts and labour warranty and aftermarket ones often fail again but they are only about £25. One very important point about smells though. Before installing a new matrix, no matter where it comes from, it must be washed own with brake cleaner to remove the oil that is on the fins or the stench inside will make your eyes and throat sore for weeks.

**DropKickMurphy** · 01-09-2009,11:36 AM

the operation was a success!

I used a 22mm plastic elbow joint (87p from the local plumbing shop) and two x 3" lengths of BMX handlebar which is 20mm stainless steel tubing. I forced the metal tubing into the plastic elbox joint and then joined the two ends of the silicon tubes which connect the cylinder head to the heater matrix and then clipped the connections with the clips which originally held the coolant pipes to the back of the heater matrix.

even with the cost of coolant added into the equation the whole exercise cost less than a tenner and works like a dream. the engine still gets up to 90 degrees (I changed the thermostat for good measure) quickly and remains there. the bypass join weeps a tiny bit of coolant - and i'm talking raindrop amounts here - which i'm monitoring daily for the time being.

i drive up to newbury on sunday and the car behaved perfectly there and back (130 miles on A-roads) which was re-assuring especially as the future mother-in-law was on board!

i am running the heater on full whack to dry the HM out, although it only blows cold air now. anyone have any estimates as how long it may take? i'm guessing aftert a week or so it ought to be less smelly. the dripping coolant from the interior air vents stopped as soon as the HM was bypassed.

if this happens to anyone else I have to say i was surprised how easy this was to fix, haynes reckoned a thermostat change was a 3 spanner job and it took me about 20 mins to fix, and the bypass took about the same time. it would have been a pig to sort out properly but i'm sure i will rue the day i bodged it come next february when the insides of the windows have frost on them and i'm wearing 6 jumpers to stave off the frostbite!

suggestions of how to heat a car without heater blowers would be much appreciated!

if anyone wants any tips on how to do this PM me - though i accept no liability if my method doesnt work for everyone

DKM

**jet** · 01-09-2009,11:47 AM

I admire your inginuity, but have to say I would be a touch worried about plastic elbow joints holding together a high pressure, high temperature system.
Can you not get hold of brass or some other metallic elbow joints of the correct diameter?

**DropKickMurphy** · 01-09-2009,02:46 PM

I am keeping my eye on it as i suspected the same - 22mm elbow joints are available in copper as well as plastic.

the reason i went for the plastic one was that i wasnt sure if i would need to weld/solder the metal pipes into it to make an effective join - the plastic is quite thick and i was able to hammer the pipes well into it. I dont yet have a soldering iron (and suspected it wouldnt be up to it) and have no experience of welding whatsoever.

I am keeping a close eye on the join and am carrying tools and coolant in the boot in case it does go, but as the commute to work is only 4 miles each way its not the end of the world if it does let go. as per the previous post i feel its better for my repair to blow out and shoot coolant all over the engine bay, rather than the heater matrix to fail and end up scalding my face hands and feet!

not ideal, but until i can afford to do it properly....

DKM

**Eshrules** · 01-09-2009,03:06 PM

Originally Posted by DropKickMurphy

not ideal, but until i can afford to do it properly....

then you really shouldn't be running the car until you do.

It's not unknown for me to cut corners/expense, but as far as the coolant system is concerned, you're not only risking your engine, but your own safety.

Seriously, you need to consider the safety implications of running boiling hot (hotter?), sticky fluid, through tubing designed to handle household water temps.