AL6 10 Posted May 1, 2014 Hi all, I'm having an issue with the heater on my 16 valve. Initially it works, blows warm air for a few minutes and then just blows cold, anyone got any solutions ? Please freezing here. Quote Share this post Link to post Share on other sites
seanl82 23 Posted May 1, 2014 Does it warm up whilst sat idling, then go cold again when cruising? How is your coolant temp on the display? Could be a duff thermostat...... Quote Share this post Link to post Share on other sites
davidwort 0 Posted May 1, 2014 check the hoses feeding coolant to the matrix through the bulkhead, if it has the matrix by-pass valves fitted (with the small bore link hose) it could be that these are playing up, or you might have a air in the system expanding and preventing water flow. If you run the car from cold, hot water from the head should get into the matrix very quickly, I'd run the car stationary and feel the hoses as the engine warms, to see where there might be a blockage, the radiator bottom hose should only get hot when the stat opens which should be 10 or 10 mins of running from stone cold. Quote Share this post Link to post Share on other sites
AL6 10 Posted May 1, 2014 Yeh that sounds like it alright, will check out the thermostat first so. Cheers ! Quote Share this post Link to post Share on other sites
AL6 10 Posted May 1, 2014 Yes it has the matrix bypass valves fitted. Had the engine running and found that the right hose got hot through to the matrix fitting but the hose on the left only got hot up until the valve, which itself was hot, but not hot after were the hose ran into the matrix fitting. I take it i've a blocked valve or does this valve only open after a certain amount of time? If this is the issue can it be manually cleared out or does it need replacing? Cheers. Quote Share this post Link to post Share on other sites
davidwort 0 Posted May 1, 2014 I think the left hose should get hot first (as it is the one that runs out of the head?), the other is the return to the metal water pipe, ideally you want to bin these valves and replace the matrix with a stronger mk3 type (identical fitment) depends on how keen you are to do the matrix though! I don't think you can get the bypass valves any more, they do seem to stick when the get old, try cleaning them out by soaking overnight in lemon juice, that might descale them and free them off. Quote Share this post Link to post Share on other sites
AL6 10 Posted May 2, 2014 I'll give the valves a go so, don't fancy changing the matrix, not too handy with the spanners. Thanks for the heads up ! Quote Share this post Link to post Share on other sites
