RobyD 0 Posted June 23, 2007 This has been an ongoing problem for years now but i really want to get it sorted as the rado will probably be for sale soon. Basically, the heating on my 1.8 16v is pants! When you first put the heater on, you get some warmish air but it gets cooler with time. If you put it on full blast, its even worse. I've done loads of searches and think i have ruled out most of the common problems... - I've checked the bypass valves by replacing with copper piping and still no heat. - I don't believe the matrix has leaked as there is no steaming up of the windscreen and no water/dampness in footwells. - I don't think the matrix is blocked as i disconnected the 2 hoses which go through the bulkhead and flushed through with a hose. It flowed through fine. Also, hot water must be getting into the car as both the input and output hoses are hot when engine is warm. - dont think there's any air locks as the car runs fine, and all of the hoses get hot such as the bottom rad hose. I've flushed out the system a number of times, but still no joy. - I've looked at the controls inside and the cables seem to moving the cogs the full way. The only thing i can think of it being is the flaps inside the system which are maybe not opening or closing the full way. To look at this properly, i reckon the dash needs to come out?? Dont really want to go there, especially not knowing for definate if it will be fixed or not Anyone got any ideas on what to try, any tips would be much appreciated :) Quote Share this post Link to post Share on other sites
joebloggsVR69 0 Posted June 23, 2007 - I've checked the bypass valves by replacing with copper piping and still no heat. :shock: That's really quite dangerous mate! You could end up with a footwell of scalding water, I've seen this happen a few times I was gonna suggest that it's a faulty bypass valve causing the lack of heat inside the car, but I guess that's been ruled out now Quote Share this post Link to post Share on other sites
Crasher 3 Posted June 23, 2007 Classic blocked matrix, I have seen it hundreds of times. You can flush and blow them out with water/air all day and they won't unblock. The only cure is a new matrix and we always fit a genuine VW matrix even though they cost 4 times what a GSF one does. Quote Share this post Link to post Share on other sites
mattkh 0 Posted June 23, 2007 Hi Do the 2 hoses going into the matrix get warm. If they do then it is definitely the flap. Quote Share this post Link to post Share on other sites
RobyD 0 Posted June 24, 2007 The copper piping was a temporary measure to check whether it was the valves or not, the valves are back on now! Yeah the two pipes get hot. Can the matrix still be blocked if hot water is circulating into the car then back into the engine bay? I put a hose through there and it comes through the other pipe... Quote Share this post Link to post Share on other sites
Crasher 3 Posted June 24, 2007 Yes, the matrix can look like it is flowing perfectly but very little water passes through the matrix tubes. Sediment settles in the bottom of the tubes and the vertical installation makes it impossible to clear it, I have seen this literally hundreds of times since the mid eighties after this matrix was first used in 84. Quote Share this post Link to post Share on other sites
dinkus 10 Posted June 27, 2007 Yes, the matrix can look like it is flowing perfectly but very little water passes through the matrix tubes. Sediment settles in the bottom of the tubes and the vertical installation makes it impossible to clear it, I have seen this literally hundreds of times since the mid eighties after this matrix was first used in 84. The man knows what he's talking about :) Quote Share this post Link to post Share on other sites
RobyD 0 Posted July 1, 2007 Cheers for replies guys! I'll have to inspect it further but if it is the matrix, where do you think i should get it from. I've heard ones from gsf and euros are not the best and its worth spending the extra to get one from vw. However, aren't the ones from gsf made by valeo like the original that is in there now, surely cant be bad?? Quote Share this post Link to post Share on other sites
RobyD 0 Posted July 15, 2007 Changed the matrix and all fixed, i once again have heat :D Wasn't as bad a job as everyone seems to make out, did it without taking the dash out which was a relief. Cheers for the tips... Quote Share this post Link to post Share on other sites
mattkh 0 Posted July 16, 2007 Changed the matrix and all fixed, i once again have heat :D Wasn't as bad a job as everyone seems to make out, did it without taking the dash out which was a relief. Cheers for the tips... Hi Well done. Did you take any photos? Quote Share this post Link to post Share on other sites
RobyD 0 Posted July 22, 2007 Changed the matrix and all fixed, i once again have heat :D Wasn't as bad a job as everyone seems to make out, did it without taking the dash out which was a relief. Cheers for the tips... Hi Well done. Did you take any photos? I took a couple just for my reference really, but they dont cover the whole job. I'll put them up anyway, they might be of use to somebody. Quote Share this post Link to post Share on other sites
Bally 0 Posted July 22, 2007 Changed the matrix and all fixed, i once again have heat :D Wasn't as bad a job as everyone seems to make out, did it without taking the dash out which was a relief. Cheers for the tips... Glad you got it sorted mate... fancy doing myn :lol: Quote Share this post Link to post Share on other sites
KADVR6 0 Posted July 22, 2007 and mine :) winter is coming :( Quote Share this post Link to post Share on other sites
herisites 0 Posted July 22, 2007 Can i butt in here. I had this problem with my car which i noticed about a month ago waiting in traffic on the M1, i put my heaters on full blast with windows open to keep the heat out of the engine bay and noticed that they went cold after a little while, if i turned them off for a bit and then back on they would heat up again. Last week my heater matrix blew and i replaced it this weekend with a genuine valeo heater matrix and checked all cabling etc and all flaps open as they should and the new matrix is connected up properly and when the engine is hot all the right pipes get hot. We also bled the system a lot to make sure there was no air in it. However whilst bleeding the system i had the heaters on and i noticed it done the same thing, they went cold after a while!! :mad: Any ideas what it could be? How do i check the bypass valves? Quote Share this post Link to post Share on other sites
