reggiebaby 10 Posted January 30, 2018 Can any one tell me how I know if the heater matrix is faulty? At the moment I only get cold air checked all cables which seem to be doing what they should. Thanks Quote Share this post Link to post Share on other sites
seanl82 23 Posted January 30, 2018 Are both pipes that come through the bulkhead getting hot? If so it's doing it's job. Check the bottom rad hose as the engine warms up. If it's getting hot at the same rate as the top rad hose, your stat is stuck open. If it stays cold until water reaches near 90 it's working correctly. If it's an early car and has a bypass valve before going into the matrix, see if it's hot either side, but cooler on the pipes coming out of the bulkhead, the it's doing it's job and your matrix is blocked Quote Share this post Link to post Share on other sites
Cressa 44 Posted January 30, 2018 Although the cables are moving, are they actually turning any cogs on the heater box. It is common for one of the plastic cogs to break and then even if you move the lever, it doesn't move inside the heater box. You need to get upside down in your car to the box as you can move them manually. PITA of a job though !! Good luck in sorting it Sent from my SM-G900F using Tapatalk Quote Share this post Link to post Share on other sites
reggiebaby 10 Posted January 30, 2018 Yes checked the top and bottom rad pipes and seem to be working correctly, it is a 1990 16v have flushed the matrix out when I had the car in bits and replaced the stat.do you know which is the bypass valve one is plastic and the other is metal on the pipes going through the bulkhead if that makes sense. Quote Share this post Link to post Share on other sites
seanl82 23 Posted January 30, 2018 That means its had the re-call, but the one on the right as you look from the front is the inlet, and the left is the outlet. If the pipe between is hot and the two into the bulkhead and matrix are cooler, then its bypassing and not feeding hot water for the blower to...........blow. Your matrix may need replacing at that point unless as Cressa has said, and either your slider isn't working properly (much less common failure than the later dial type), or the foam inside the heater box where the flap is has broken down and both hot and cold air are being blown through. Is it cold or just warm, and does it cool when driving but warm up when stationary? Quote Share this post Link to post Share on other sites
reggiebaby 10 Posted January 30, 2018 Thanks, cool all the time no heat at all. Quote Share this post Link to post Share on other sites
reggiebaby 10 Posted February 1, 2018 That means its had the re-call, but the one on the right as you look from the front is the inlet, and the left is the outlet. If the pipe between is hot and the two into the bulkhead and matrix are cooler, then its bypassing and not feeding hot water for the blower to...........blow. Your matrix may need replacing at that point unless as Cressa has said, and either your slider isn't working properly (much less common failure than the later dial type), or the foam inside the heater box where the flap is has broken down and both hot and cold air are being blown through. Is it cold or just warm, and does it cool when driving but warm up when stationary? It's seems that the matrix pipes going through the bulk head are not really getting hot does this mean I need to replace the matrix? Not a job iamb looking forward to so tiring to make sure before I start. Cheers Quote Share this post Link to post Share on other sites
seanl82 23 Posted February 1, 2018 Remove the bypass valves and just plumb the pipework directly to through to the bulkhead using copper pipe like below. You should then be able to tell if its the matrix or the bypass valves that are faulty. More likely bypass valves, but if your matrix is old then the additional pressure on it by removing them may cause it to pop. Worth replacing it if you can as I'm not sure the bypass valves are still available. If you can get them then you may be ok. Quote Share this post Link to post Share on other sites
STU175 0 Posted February 4, 2018 Remove the bypass valves and just plumb the pipework directly to through to the bulkhead using copper pipe like below. You should then be able to tell if its the matrix or the bypass valves that are faulty. More likely bypass valves, but if your matrix is old then the additional pressure on it by removing them may cause it to pop. Worth replacing it if you can as I'm not sure the bypass valves are still available. If you can get them then you may be ok. I couldnt source replacements and havnt had any problems in the 15 years ive had them removed/bypassed.... Its bound to pop next time i start it after saying that.....lol Sent from my SM-G920F using Tapatalk Quote Share this post Link to post Share on other sites
