Heater problems

[matt1990]

my mk2 heater keeps coming through cold when it gets up to temp i was told this is a normal problem, i was just wondering if its something i could get away with fixin myself and if anyone else has had this problem???

[Toughjeans]

axenige is your man try and pm him

[axenige]

It sounds like a water circulation problem too me, Mk2's have a set of valves which are in line form the water pipes coming from the engine block and going to the water matrix for the heater unit. I would check these first to see if they are the problem,there not really much else that can go wrong apart from the heater matrix failing. The system does work o.k. without the valves (as with my Golf) but Eliot has told me there is a chance of the matrix blowing if the water pressure gets to high, apparently this is why the valves are there in the first place. I would run the engine up to working temperature and then check the hoses each side of the valve unit and see if there as hot each side of the valve unit, with the fan in the normal position that you have it when the fault occurs, wait until the air through the heater goes cold then check the pipes and valves, if not it then check the matrix itself.

P.S. How's the wonderful world of Screw-fix this week

[matt1990]

ok gona try that today, one of the valves looks new anyway


Been off since friday but back at screwfix 2moro your bits came in the other day, take it you've got them now?

[axenige]

Yep the old man picked them up for on his travels the other day

If your not sure if the valves are at fault then you can remove them and plumb in some short sections of copper pipe to try the heater unit without them.

The other thing which is worth looking at is how silted up the cooling system is, it maybe that the water circulation through the matrix is being restricted by a build up of muck in the cooling system. My Golf is terrible for this problem and I've flushed the whole system more times than I've had hot dinners but it still rusts up.

If not like I said look at the matrix itself, this would still get warm from cold due too the heat being converted through the pipework, and intern then heating the water in that is already in the matrix. So again you need too conduct and fault finding experiment as you would if using the heater. If the matrix is at fault the heater fan unit is working in the same way as the engine fan, and the matrix is working as a radiator would under the bonnet, I.E. starting off warm and then being cooled by the air drawn through the matrix and not as it should a heat exchanger were the cold air is warmed by the matrix.

P.S. I'm assuming that you've checked the water pump and that it's operating correctly, again check the top and bottom radiator hoses to see if there the same temperature once the engine is fully warmed up and that the thermostat in the water pump is fully open.

[matt1990]

yeah the water pumps fine, i waited for it to get up to temp last night and its the hose that goes in from that black valve that just goes cold and the rest are all warm still, im gona try a bit of copper pipe on it next time im off, thanks for the advise dude

[axenige]

Not a problem M8

P.S.
Oty
89-85335 1

89-56552 1

Sould sort you out then on this one ;D ;D

[matt1990]

haha got some copper pipe laying about somewhere, im gona sort it out this weekend too cold to do it after work


I just realised i need to clean my engine bay well im at it

[Smokeydub]

Hope you manage to sort the problem soon!

Can't be doing with heater problem at this time of year.

[matt1990]

Yeah should do, hopefully that works hows your golf going ?

[axenige]

oh it can never look too clean under the bonnet M8, tell me Matt do you have loads of thick greasy muck laying on the tops of the inners wings, and all down the front of the engine block, this muck is black and seams to have grit in it. The reason I ask is both my golf and Andy's had the same problem, but for the life of me I can't think how it got to be like that in the first place.

[Smokeydub]

Should be putting the engine back in next Saturday, but I think we'll be lucky if we manage to get it fired up then!

[matt1990]

yeah i do have that well there what looks like grease lines down the inner wings, i picked up a cheap cleaner and used that but doesnt wona shift it to easy. Also got a fair amount of gearbox oil from the last gearbox all over the place

[matt1990]

admin said:

Should be putting the engine back in next Saturday, but I think we'll be lucky if we manage to get it fired up then!

Ah well least you have an engine crane lol when i changed the t25 one we devised one using a 2 scaffold poles very scretchy. Hope it goes in alright tho dude

[axenige]

Yep put some bits on today, and then took some more off ;D as they need some TLC, and cleaning. The valve train breather pipe and its unit are completely clogged up with oxidized oil and the pipe itself is in a very poorly state, so we going to try and revive that with old trick of mine, which is to soak the pipe in power steering fluid which contains some of the chemicals which are present in rubber, this sould restore some of the life back into it, as long as its not too far gone already.

[Smokeydub]

matt1990 said:

admin said:

Should be putting the engine back in next Saturday, but I think we'll be lucky if we manage to get it fired up then!

Ah well least you have an engine crane lol when i changed the t25 one we devised one using a 2 scaffold poles very scretchy. Hope it goes in alright tho dude

Sure it'll go in just fine!

What could possibly go wrong when we've got the Golf Doctor with us!

[axenige]

matt1990 said:

yeah i do have that well there what looks like grease lines down the inner wings, i picked up a cheap cleaner and used that but doesnt wona shift it to easy. Also got a fair amount of gearbox oil from the last gearbox all over the place

White spirit m8, and soak it well first or even cellulose thinners as long as the paint is the factory 2PAK

[matt1990]

The golf doctor lol,axenige how do you know so bloody much! ;D what do you do work wise?