custard-rallye 25 Posted January 9, 2010 when i bought my 205 rallye a few weeks ago the heaters were crap when driving it home so i thought the old owner had removed the thermostat so i checked and it had the thermostat. so i tried bleeding the system, still no luck. i bought a new thermostat as i get bits trade price and there was still no change so tried flushing the system but before i did that i took the little plug off the rad to drain it and nothing came out i poked an extension in the hole then the water came out and what looked like mud but i was told this happens when you put to much water in the system and not enough coolant so i took the expansion bottle off aswell and cleaned it out as it had the mud at the bottom aswell so after that i flushed the system then drained it and topped it up again with coolant then bled it. still the heater is rubbish with only a little heat coming through. i thought it might be the heater matrix but i disconnected the two pipes going to it and poured water in the top pipe and and poured out the bottom any ideas?? Share this post Link to post Share on other sites
grandos 16 Posted January 9, 2010 (edited) When you flushed the system did you use a hose pipe to flush and then back flush the system? Do the radiator separately from the engine to avoid all the crap going into the block (do the same with the matrix) Ensure all the flushing water is out of all the components. Then using a 50:50 mix top up the entire cooling system, use the bleed screws in the top coolant hose (near bulkhead) and the head (to the left and above the thermostat). With the system up to the max mark start the engine with the expansion cap off, turn the heater to max and fan speed to max and run till you get hot air through the vents. Topping the system up to the max mark as it drops. What haynes will tell you then is to allow the car to cool then top up further (could do this in the morning) Once the system is full its ideal to run to check the fan kicks in and out a couple of times to check everything is working. With the cap back on. Does the gauge show the vehicle is at operating temperature? If the system is still not working then you need to check if the heater matrix is heating up (& pipes to and from the unit.) Is the internal flap within the heater box moving to allow the hot air to mix before coming out the vents. Edited January 9, 2010 by grandos Share this post Link to post Share on other sites
Redtop 14 2 Cars Posted January 9, 2010 Probably is the heater matrix and it still being partically blocked. The rusty mudy water has more than likely done that. Put a new matrix in it and blead all the system again, with plenty of good antifreeze. Are you driving the car as a daily in this weather? If so the water in the system could be freezing going to the matrix but the heat of the engine has thawed the coolant round the engine itself making it work ok. Share this post Link to post Share on other sites
Rock Lobster 28 Posted January 9, 2010 I had this problem with my heater. After fitting a thermostat that some kind person had removed it still wouldn't heat up. Turned out that my heater matrix was partially blocked and took bloody ages to clear out! I did it by disconnecting both top and bottom and hoses to the matrix and shoving a hose pipe over the outlet and inlet in turn. You'd be suprised how long it takes and just how much crap you get out of it. It helps if you pulse the hose aswell to get all the muck out. Bleed the system, top up and cross your fingers! Share this post Link to post Share on other sites
custard-rallye 25 Posted January 10, 2010 i have a yellow rallye for spares so might take the heater matrix out of it and use it Share this post Link to post Share on other sites
bungle 0 Posted February 16, 2010 I also have a similar problem, I had not heat from the heaters. Phase 2 1.6 Gti (1992) Today I fully drained and flushed the system (radiator, then block then heater matrix) all back together with fresh coolant. Started her up and it started to warm up, got to a decent temperature, but never hot hot if you know what I mean! Went for a drive, whenever I am moving the blowers are mildly warm at best, in traffic they get a bit better. Any ideas why this may be? May the engine not be getting up to temperature? I was driving quite hard so I would imagine it shouldn't be this. The oil temperature never seems to get above one notch on the gauge, even after a long fast drive, any ideas? Cheers for the help, would like to get this sorted, its far to cold with no heater!! Share this post Link to post Share on other sites
welshpug 1,647 Posted February 16, 2010 Is the coolant getting up to temperature fine? might be a stuck thermostat not keeping the engine around its optimal temperature, ties in with the heaters being better in traffic. Share this post Link to post Share on other sites
bungle 0 Posted February 16, 2010 It seems to be, it gets up to about half way up the scale of coolant gauge. I was under the impression that the engine would be hotter then usual if the thermostat was stuck shut? It is not shut open, I know as I had it out this morning to flush the block. Whilst on topic the fan seems to not do a lot until I turn it full max then it gets a bit better, is this normal for a 205?! Cheers Share this post Link to post Share on other sites
bungle 0 Posted February 17, 2010 Any ideas people? Cheers! Share this post Link to post Share on other sites
lagonda 41 Posted February 17, 2010 Take it you flushed the heater matrix separately, or via the pipes leading to & from it. I changed my heater matrix recently, & there was quite a lot of dead leaves, dust etc in the heater box, which would have made it less efficient...might be worth checking out as it's had 20 odd years to build up! To be honest the heater output, indeed ventilation, is pretty poor on the 205, so it could be you're expecting too much. The oil temperature won't rise much in this weather. Water temperature will also be on the low side unless you're in traffic....fitting a thermostat that opens at a higher temperature would help. Before doing that I'd leave engine idling until water temp. needle is pointing vertically, then try your heater. That way, you'll know if it's a circulation problem or whether it's worth fitting a different thermostat. It's pretty easy to remove the heater fan motor....would recommend oiling bearings on that. Will run faster, last longer & be less noisy. The bearings are oilite bushes, which retain oil. You'll need to drip oil onto the bearings, repeating a few times, then leave it to stand for a day. Then put it back & enjoy! Share this post Link to post Share on other sites
bungle 0 Posted February 17, 2010 I did flush the heater matrix separately including the pipes connected to it, at first it was blocked but soon cleared with the hose pressure, I was surprised to not see any dirt etc. come out though. I went to my local garage today and they also suggested it could be the thermostat so I am going to change that tomorrow for a new one. I gather I get access to the heater box from the drivers foot well, it is easy to recognise what I am looking for? I will be looking to check that over tomorrow also. Cheers for the help! Share this post Link to post Share on other sites
SurGie 54 Posted February 18, 2010 The heater matrix is on the drivers side and the heater fan is located on the passenger side, both underneath the dash. Share this post Link to post Share on other sites
bungle 0 Posted February 18, 2010 Cheers, I will see what I can do today Share this post Link to post Share on other sites
