Nothing but cold air....FIXED!!

[davidwort 0]

Something else I forgot to mention.....

 

Before all this I had other issues with the heater. It would kick out hot air which would get colder as the water temp got hotter. Is that connected to what's happening now?

 

could be a partial air lock expanding as the temps rise.

[dragon green 5]

Changed the matrix new years day.

 

how old is your motor?? and how big a job is it ??

 

i have read that the dash has to come out - but hope that my 89 16v maybe a little easier than the later ones.

 

skinny - same issue as mine was warm then suddenly went cold/luke warm. i would ditch the valve, reverse flush, 2 bottles of the fancy anti freeze and see what happens. carry a spare pipe to bypass just in case it does burst - so far mine has been good and i spend at least 20 mins a night in stop start traffic. no leak and having to turn the temp down as its too warm in there.

Mines a "92" early dash,it took all day, and an hour of the next,done outside,and ruddy cold !yep dash out

viewtopic.php?f=45&t=83262

[skinnyman9000 0]

Im gonna try everything under the sun before i revert to taking the dash out! The last time i did a major job on the rado i replaced the sunroof, and i really dont fancy doing anything similar anytime soon.

 

To make matters worse the sunroof still doesnt work :mad2:

[skinnyman9000 0]

Well i took her out for a little run this morning to give it the chance to work any air bubbles out the system. I got cold air the entire journey, apart from a 30sec stint where i had luke warm air accompanied by a burning smell :scratch:

 

Its footy this afto so i'll have to have a crack at flushing the matrix 2moz morning. Beyond that i dont really know what else i can do on the driveway without spending some dollarz.

 

Although this morning when i was tinkering i did notice something. Ive read guides that says the pipe leading from the bottom of the radiator should remain cold until the temp gauge hits half way, at which point it should become warm as the stat opens. Now, when i first start the car up this pipe does remain cold, but only for say 5 mins, then as soon as the temp needle moves a touch it starts to warm up. So the temp gauge has only just touched 70C when this pipe starts to heat up.

 

Sounds to me like everything is broken :lol:

[skinnyman9000 0]

Well, ive been out today and had another crack at everything. I flushed then reverse flushed the matrix, some gunk came out, but not much, so i then decided to flush all the coolant again, stuck some coolant flush in there and made sure the whole system was nice and clean, filled her back up and bled the system.

 

AND

 

Im still getting the same cold air through the blowers. Im guessing its heater matrix time? Now is it worth getting a quote from a specialist for this? Or will they just have my pants down? If i do need a new matrix i think i'll be going with the TT option so i can replace the bypass valves for bog standard hoses.

[dbug 0]

before you pull the dash out swap the pipes. ( cheapest and easiest fix + nothing lost if matrix is fubar then dash will need to come out anyway )

 

also did you run the engine up till the fan cut in ??

 

to correctly fill and bleed you should fill her up cap off and top up as the level drops ( fill it full you wont hurt her ) , as it becomes obvious that the coolant is getting warm( steam rising from the open neck of the bottle or top rad pipe very hot ) replace the cap and run the engine fast idle ( try to hold at 2000 rpm for a little while) up till the fan kicks in.

turn off and allow to go cold.

 

once cold ( overnight or a good 3/4 hours ) open bottle and refill to level and replace cap. run the car and check level again after next run top up if nessesary. shouldnt take more than 3 top ups to have cleared all air traps and hopefully a nice warm car too. :D

[skinnyman9000 0]

Well i did the coolant bleed as per the guide on E38, but i must admit i didnt go to the lengths as described above, hmmm, wonder if its worth doing that. But the air im getting out isnt even slightly warm, its stone cold.

[dbug 0]

Well i did the coolant bleed as per the guide on E38, but i must admit i didnt go to the lengths as described above, hmmm, wonder if its worth doing that. But the air im getting out isnt even slightly warm, its stone cold.

 

info came from a vw tech - this is the process they use in the workshops on all the older cars ( has worked for my mk1 goof, t4, v5 beetle and rado so is tried and very well tested. )

 

the newer ones have to use a vacuum system due to the complex twist turns and piping routes

[davidwort 0]

I've changed the coolant umpteen times on the valver, all you need to do is top up the last litre or two slowly into the header tank, a 2L coke bottle with a screwdriver stab or two in the top does the trick nicely, and you can stand it up on the header tank and leave it.

You may or may not need to top up a cupful of coolant after the first drive (one full heating and cooling cycle), but I've never had more trouble than that.

[Supercharged 2]

Yep - fill slowly, VW say 5 mins and you'll have no issues at all... I usually warm up with the cap off and wait for the stat to open then shut the engine off...

 

Let it cool down, top up if needed, cap on and you're done.

[skinnyman9000 0]

Well im 99% sure that the way in which i did it was correct.

 

I removed the bottom radiator pipe to remove all the coolant. I then filled the system with water and coolant flush and performed the flush. Removed the bottom rad pipe again to empty the system, and ran through with water until it was running clear. I then reattached all the hoses. At this point i removed the top radiator hose and filled the system with 40% coolant 60% water. I filled until the coolant was to the top of the hose, i then reattached this and filled the rest into the expansion tank. Once it was full i started the engine, with the blowers set to full. I now had the expansion tank cap off and i began to squeeze every pipe i could get it. After 5-6 mins the lower rad pipe began to warm up, indicating the stat opening. I continued to squeeze every pipe and slowly filled the coolant up as required. Once the coolant began to boil i turned the engine off. I then allowed it to cool, topped the coolant up and attached the expansion tank lid. I then ran the engine until the fan cut in and out twice. At this point i turned the engine off, allowed it all to cool, and then topped up the coolant again.

 

Im pretty sure thats a solid method, and im still getting cold air. Surely it all points to the matrix now?

[Supercharged 2]

Is water actually flowing in and out of the matirx? Pipes both the same temp?

 

Not had time to read the thread but sounds like faulty bypass valves if fitted

[dbug 0]

Surely it all points to the matrix now?

 

no it points to the matrix circuit. which INCLUDES the valve that you have been trying to get to work.

 

you can rest easy that the engine circuit is working as it should - the fan/temp sender is working and the thermostat is working.

[dbug 0]

I then filled the system with water and coolant flush and performed the flush. Removed the bottom rad pipe again to empty the system, and ran through with water until it was running clear.

 

if the valve is closed then you will not have flushed the matrix only the engine/rad.

 

you need to open the whole system up to flush the matrix. the valve must be fubared if you still have no warm air. dont waste any more time flushing, fit the straight pipes without the valves and test it that way ( try to save as much coolant as possible - must have cost you a fortune by now )

 

if the matrix is shot then you will smell it in the cabin as she warms up and probably get the screen fogging up in this weather if not you will get warm dry air.

[skinnyman9000 0]

I'll go with the new pipes then and just removed the bypass valves, then onto the matrix if the problem remains. Ive spent £25 on coolant so far, so i'll be saving as much as i can when i remove the valves.

 

Thank god i have access to another car otherwise i'd be fubared in this weather!

 

Thanks ever so much for the help chaps, really no idea what i'd do without this place :notworthy:

[davidwort 0]

I think we've covered all this,

the by-pass valves seem to operate correctly and the flow of warm water suggests the matrix head is allowing a flow of hot water in and out but the matrix core itself is not flowing.

My bet is a the matrix needs replacing but the cores are not actually leaking.

Once it's replaced it can be sawn in half to prove the problem :)

[skinnyman9000 0]

Right then men, replacement rado matrix, or a TT matrix?

 

Also, roughly how much is this likely to set me back by? I cant seem to find the heater matrix on ETKA.

[dragon green 5]

Mine from the stealers was £105 !!

[davidwort 0]

Right then men, replacement rado matrix, or a TT matrix?

 

Also, roughly how much is this likely to set me back by? I cant seem to find the heater matrix on ETKA.

 

just an ordinary mk3 matrix will do you fine, in fact they should be the same part as what's stocked for a mk2 or Corrado, if GSF do a Valeo one then go for that, otherwise the best quality and longest lasting will be from VAG themselves.

It's only the old 1990 ish era genuine VW matrixes that had the iffy end caps and needed the by-pass valves, but I'm sure there's more than one pattern matrix out there that is of questionable quality.

I'd take the old one out and compare it to the new one at the GSF/ECP desk, if it's anything like the radiators then the quality differences will be obvious.

[veedub16v 0]

the mk3 matrix is better than the mk2 and corrado one - no bypass valve needed!

 

theres nothing wrong with gsf's matrix. its £40ish and the pipes you need to delete the bypass valve are about a tenner, although the last time i bought them it was for a mk2 golf, the pipes for a corrado may be a bit longer. if you wish to waste money at vw though its up to you

[skinnyman9000 0]

Anyone know the gsf part numbers for the pipes I need to replace the bypass valves?

[davidwort 0]

Just ask them for mk2 16v hoses to and from matrix, the parts guy should be fine with that.

I'm using silicon hoses from SFS, one reducing 90 deg elbow (from head flange) and a 1m length of SFS hose cut into two lengths.

Elbow and straight length clamped together with an SFS alloy hose joiner, matches my blue samco hoses nicely and fits fine.

Cost under 30 quid all in.

[skinnyman9000 0]

GSF only had the feed pipe available for some reason, oh well. But i'll have the feed pipe and matrix tomorrow, and i'll nip to VW to get the other pipe.

[skinnyman9000 0]

Sorted!!

 

I started by replacing the bypass valves with hoses and it seems to have fixed it. I thought the valves were working, but would seem they werent. i now have lovely warm air, and the coolant system is behaving alot better.]

 

just want to say thankyou to everyone in this thread for your help :clap:

[Wullie 1]

Congratulations. Now you have heat we will probably get a "Barbeque Summer"