Changing heater matrix?

Hey Guys,
My car has had its 3rd set (all from the scappy) of heater bypass valves, and I was thinking of buying some brand new from eurocar parts or gsf. But I have found the price difference of the bypass valves and a new matrix is 5. So im thinking of buying a new matrix and fitting it in over a weekend.
However my headgasket needs doing (for the 1st time), and well as all the other things that need replacing for a car thats done over 130k miles.
Im really confused, do I get the bypass valves and get the heating to work, or replace the matrix and slowly get the headgasket etc done. Its only a 1.6 CL but its been in my family since 1990.

Also does anyone have a rough idea how much it would cost to do the headgasket and clean the bottom end.

Regards, Pritesh

 

If there isn't a problem with the matrix just bin the bypass valve. My '91 Mk2 never got one fitted and is just fine. The bypass was fitted as a panic measure after a couple of matrix burst, it is the weakest link in the system if it over pressurises.
If the headgasket is failing and so pressurising the cooling system even a new bypass valve won't get you any heat as it will be doing what it is supposed to do. You need to bite the bullet and get the headgasket changed before doing anything else, and hope the matrix is fine as they're buried in the dash and so a right job to change.

Barkstar

 

Also something that im considering doing. I read in some previous posts after doing some searching, that replacing the bypass valve with a pipe can cause the matrix to burst! Is that actually the case and how can I check if my matrix is not up to scratch?

Thanks

 

Yeh I dont know whether my matrix is up to scratch. Some people here have had their matrix burst even with the valves installed.
Thanks Barkstar, I guess I had better get my headgasket done. I have been dreading it, along with the waterpump, oil pump etc.

 

IIRC there were only a handful of cases of burst matrix and they will only burst if the system is over presurising due to another fault. VW decided to take no chances and beefed up the matrix on the Mk3 - did I read that it will retro fit the mk2? The matrix is fine in normal use, it just the weakest component in the whole system if there's a failure.

If what you said were true then how come my Mk2, which never went in for the recall, hasn't poached my feet? The bypass valve is presure sensitive and diverts the water away from the matrix if the system has a fault (like a failing headgasket). Over time they corrode internally and seem to most often fail safe - so no heater. Lots of others have binned them, and used plain pipe and I won't be fitting one anytime soon.

I don't recall seeing any thread where a matrix has burst suddenly, though quite a few have started leaking due to old age.

Barkstar

 

Ok cool, so more than likley I wont have any problems just sticking a pipe in the valves place.

If I post up a pic later of me pointing at what I think is the valve, could someone tell me if I'm right or wrong.

Thanks

(Sorry for jacking your thread muppet9966 )

 

picture

Hi

Looking forward to the picture.

 

Ok could someone tell me which one it is.



Thanks again.

 

Anyone?

 

I'll have a look when its daylight but I can only tell you what yours has that mine ain't - But I can't picture A under the bonnet on mine.

Barkstar

 

Ok cheers

 

itsdiagram A. i had the matrix expload on the way home from when i brougth the car and it not very nice. if i was you i would buy brand new valves from vw at 32 but if you have no joy with that then reverse flush the matrix system or just buy a brand new matrix it is deffently not worth fitting a second hand one

 

interested in this thread as my heating is well below par,and think the same valve is doin me a dis-service ,if you by-pass the valve pictured 'a' where does the ickle pipe beside it go then ??

 

Ok thanks grump, I shall take a trip to GSF before the weather gets too cold

 

im not certain on this but i think you just put a copper pipe in the to pipes on the left so the right one is not used (from diagram A) but you will have to check that but like i say it is not worth the trouble risking your matrix.

 

Just out of interest, could I take the valve off and clean it out? Would that make any difference?

Thanks again

WM

 

Iv Tried That A Few Times And It Has Never Worked.

 

Im thinking of replacing my valves with copper pipes, but I dont know whether my failing headgasket will put strain on the matrix. The back of my engine is oily, looks fresh so I think its the oil leaking out of the engine, and im losing abit of water and oil, not that much though.