newbie with heater problem!!!!!!

[wullvfr]

hello all,not only am i knew on here but i have just bought my first polo....1994 mk3 genesis coupe.

the problem is........

the heater only works on the third setting(highest)which i put down to the resistor that sits along side the heater matrix,bit now all of a sudden it only blows out cold air.

it put out warm air on friday and saturday,and whilst doing this the temp gauge stayed in and around the 70-80 mark,but now that it is only putting out cold air the temp gauge goes up to 100-110 mark.

according to the manual the needle should stay in and around the 90-100 mark..........

i have not had the chance to check any possible causes yet except for a quick check on the hoses that goe into the matrix,which were warm,not roasting hot but they were definately warm.because the temp is going up,i definately don't think the thermostat is the culprit.....possibly the system needing bled!!!!!

any tips would be much appreciated


william

[Tim_GTi]

By freak chance, the thermostate could be getting stuck closed, it's worth giving the system a bleed as you said and taking it out and having a ganders.

[alexperkins]

The top vents only kick out cold air anyhow. Heat comes from the footwell and windscreen vents

As for the heating issue, it sounds like the thermostat may be getting stuck or there is an airlock

Put the heater to hot position with fan off. Open the bleed screw on the right hand side of the heater matrix (its a white twisty screw that is ontop of the pipe).

Start the engine, and gently squeeze the big radiator pipes. If there is air, it will bubble. Wait till all the bubbles are gone, and its running smoothly, then screw it back up.

[wullvfr]

had a look this morning and bled the heater matrix.....problem solved!!!!

hot air immediately:)

as for the top vents blowing cold air,what vents are you referring to?

i get hot air blowing from everywhere,depending on what setting i have it on obviously.

i do believe the head gasket may be blown,the coolant level was slightly low.nothing major.also excessive smoke from the exhaust but it was very cold this morning and there is signs of emulsification on the oil cap......no signs on the dipstick yet.



william

[alexperkins]

The vents for your face - these pull air from the plenum chamber directly and wont blow hot air at all They are basically for fresh air from outside

Glad to hear you now have heat!!

The emulsification is nothing to worry about atm. Take it for a good long drive and see what happens. Short journeys around town can have this effect, and make you think the gasket is going when it is infact fine.

[wullvfr]

Short journeys around town can have this effect, and make you think the gasket is going when it is infact fine.

way ahead of you on that one

i knew this as a possible cause and the worrying thing is the car does not do short journeys!!!!!

i topped the coolant up this morning and after work i checked it again and it was low.


william

[alexperkins]

Hmm. have you any visible oil leaks on the outside of the engine?

[wullvfr]

i have not had a good check but the oil level is good.there is a slight showing of oil from the cam cover.


back to the short journeys,i was thinking.it depends on what you class as short journeys!!!!!!!

the guy i bought the car from used it as his daily commute which would have been roughly 25-30 miles each way.so 50-60 round trip.

i do 20 miles each way.to me that is not a short journey but i suppose it may be a short journey to others and may have the effect of emulsification.


william

[alexperkins]

what speeds are you doing on your journey?

Cam cover is a common fault. New seal will rectify that.

[wullvfr]

what speeds are you doing on your journey?

very twisty roads so never above 60mph.mainly using 3rd,4th and 5th.averaging probably in and around 30-35mph.....40mph at a push.

Cam cover is a common fault. New seal will rectify that.

its not too bad atm so going to leave until i do the head gasket....if that is blown!!!



william

[wullvfr]

over tha past week of driving the ca i have kept an eye on things to try and come to a conclusion on what's wrong......

i am having to top the coolant up almost on a daily basis,definately every second day at the best.on a daily basis when i check it it may have only went down slightly.

i cleaned up the emulsification on the oil cap to see how long it takes to come back,and it's taking it's time.it's not too bad!!!!

there is constantly excessive clear smoke/steam coming from the exhaust...........

so i am 100% confident the head gasket has blown!!!!!

heater problems are still there but what seems to happen now is......when slowing down for a 30mph zone the heater blows out cold air and when speeding back up it blows hot air???????????

is this consistent symptoms for problems with water pump?i have heard this somewhere!or is it just a bad build up of air in the system,possibly due to the blown gasket?if i bleed the heater matrix in a village when it has decided to blow cold air it immediately blows out hot air.this is the reason for me thinking this.




william

[alexperkins]

if the steam is always there id say its most certainly head gasket. get it sorted as soon as you can!