NOODLE Posted March 12, 2012 Share Posted March 12, 2012 After buying my supra a couple weeks ago it was all good until it randomly started to blow cold air. when i tried bleeding the system i got hot air again, but once i drove the car about 2 or 3 miles it went cooler until it was cold again, i then changed the thermostat, jacked up the front of the car and bled it again and still no hot air. i did notice when i changed the thermostat the flow of anti freeze wasnt very good, so i removed it just to get me home. the car doesnt seem to be over heating at all and the temp gauge stays at the running temp and has not gone over half way. i have a feeling the pipes running into the heater matrix have corroded and blocked the system but both pipes going into the bulk head are warm when up to temp. the pipes just feel brittle when u squeeze them has anyone had this issue? any help would be great thanks Quote Link to comment Share on other sites More sharing options...
dan294 Posted March 12, 2012 Share Posted March 12, 2012 Its a long shot, but see post number 16 in the attached thread. I had the same sort of fault on mine: http://www.mkivsupra.net/vbb/showthread.php?49871-Heater-Maximum-Output-Temperature-Too-Low/page2 Quote Link to comment Share on other sites More sharing options...
Scott Posted March 12, 2012 Share Posted March 12, 2012 Check the mechanism for opening and closing the heater matrix valve hasn't came off. This can be seen underneath the glovebox on the passengerside IIRC, behind the dash. It's a rod that pulls and pushes the valve to open. It's quite common for this to detatch itself causing cold air. That wouldn't explain why you had temporary heat though. Is the air stone cold regardless of engine temp? Are the pipes leading to and from the bulkhead roasting hot? Ie both are very hot to the touch and after a run you would struggle to hold them? Generally when you have a blockage the "out" pipe is significantly cooler, barely luke warm. Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 12, 2012 Share Posted March 12, 2012 (edited) If you have to bleed the system then its losing coolant somewhere. Is there any coolant in the expansion tank ? do you have an expansion tank ? i checked a supra a little while ago and it had no tank, hence it kept needing to be topped up and bled !! Is your passenger footwell damp, (leaking heater matrix) Edited March 12, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 12, 2012 Author Share Posted March 12, 2012 If you have to bleed the system then its losing coolant somewhere. Is there any coolant in the expansion tank ? do you have an expansion tank ? i checked a supra a little while ago and it had no tank, hence it kept needing to be topped up and bled !! Is your passenger footwell damp, (leaking heater matrix) not losing water the expantion tank has water in it topped up to the max after changing the thermostat, io did have to top it up when i brought the car tho but i put that down to the car being stood up for a while. Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 12, 2012 Share Posted March 12, 2012 (edited) Then check as mentioned above to see if the heater flaps working. I'd keep an eye on the coolant level though just incase it does have a leak. How much coolant did you have to put in it when you first had it ? Edited March 12, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 12, 2012 Author Share Posted March 12, 2012 Its a long shot, but see post number 16 in the attached thread. I had the same sort of fault on mine: http://www.mkivsupra.net/vbb/showthread.php?49871-Heater-Maximum-Output-Temperature-Too-Low/page2 right im gonna go take a look :-) ive gotta refit the thermostat aswell so if i dont reply straight away i will get back to you cheers Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 12, 2012 Author Share Posted March 12, 2012 Then check as mentioned above to see if the heater flaps working. I'd keep an eye on the coolant level though just incase it does have a leak. will do, tanks for the help :-) Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 12, 2012 Share Posted March 12, 2012 Dont just use tap water to refill the system (toyota coolred or an ethylene glycol based coolant) should be used Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 12, 2012 Author Share Posted March 12, 2012 ye got sum ethylene glycol based coolant, red stuff, right ive put the thermostat in taken off the top coolant hoses and bled it from there ive now got heat i think it was just a big air lock sadly it wasn't the simple heater flap. . cheers guys appreciate the help. im gonna keep an eye on the water level now and make sure there's no leaks. and hopefully jobs a good en. . Quote Link to comment Share on other sites More sharing options...
Terminator Posted March 12, 2012 Share Posted March 12, 2012 I would suspect the rad cap, they have a nasty habit of not letting you know when they have failed. Quote Link to comment Share on other sites More sharing options...
wile e coyote Posted March 12, 2012 Share Posted March 12, 2012 they can take a bit to bleed , ran my brothers for a bit with cap off loads air come out Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 12, 2012 Author Share Posted March 12, 2012 ok il get a new rad cap to be on the safe side cheers, is it best to get a standard one rather then a trd or anything like that? Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 12, 2012 Share Posted March 12, 2012 Fit a stock Toyota rad cap, the TRD run at a higher pressure which you have no need for Quote Link to comment Share on other sites More sharing options...
NOODLE Posted March 13, 2012 Author Share Posted March 13, 2012 Fit a stock Toyota rad cap, the TRD run at a higher pressure which you have no need for ok cool, i forgot the trd cap is for a different engine lol i checked the water today and it hasn't gone down, but the circulation isn't very good i ran the car up to temp with the cap on and tbh it doesn't feel like theirs any pressure building in the system, Ive already booked it in for a new water pump and radiator cap so it will be sorted soon. the reason for the new water pump is purely cus the cam belt was done before i brought the car and im unsure whether the pump was changed or not so id rather be safe then sorry. Quote Link to comment Share on other sites More sharing options...
Lude Posted April 22, 2012 Share Posted April 22, 2012 Its a long shot, but see post number 16 in the attached thread. I had the same sort of fault on mine: http://www.mkivsupra.net/vbb/showthread.php?49871-Heater-Maximum-Output-Temperature-Too-Low/page2 my heaters have been crap lately, searched on the forum and found this. looked under my glove box and my rod was dis-connected too! what a easy fix, that i would have never in a million years thought of looking. i assumed it was all digitally controlled due to the number of connectors behind the dash lol Quote Link to comment Share on other sites More sharing options...
NOODLE Posted April 23, 2012 Author Share Posted April 23, 2012 my heaters have been crap lately, searched on the forum and found this. looked under my glove box and my rod was dis-connected too! what a easy fix, that i would have never in a million years thought of looking. i assumed it was all digitally controlled due to the number of connectors behind the dash lol i wasnt so lucky tbh i had mess about alot to bleed the system properly all done now tho cars been running sweet since, except the speed sensor showing a fault :-/ oh well will get it sorted soon enough :-) Quote Link to comment Share on other sites More sharing options...
Slam Posted April 23, 2012 Share Posted April 23, 2012 they can take a bit to bleed , ran my brothers for a bit with cap off loads air come out Yer remember that,also worth checking your conectors are conected behind the dash. I had this isue:blink: Quote Link to comment Share on other sites More sharing options...
Dnk Posted April 23, 2012 Share Posted April 23, 2012 To help jiggle out trapped air you can run the car up to temp with the rad cap off with the heater set to full hot and raise the revs on the engine from idle to approx 2500 rpm then let it drop and repeat a couple of times. Quote Link to comment Share on other sites More sharing options...
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