cefiro_drifter Posted October 6, 2011 Share Posted October 6, 2011 Right im stuck and about to take the z apart and scrap it. Little long as im trying ti explain all the issues as and when they happen and gettign as much detail as possible. bought car off a **** that talked alot of @*!# and found out the fans werent working and as a result it over heated pretty well on the way home ( over flow jetting water out, lots of loud vibration sounds from rad, steam and lots of it etc etc). Evidence that its done it before as water was clean and clear with no hint of anti freeze in it so no idea how many times its done it and how badly. Anyway i decided to get an uprated Alloy rad and twin 12" electric fans ( worked very very well in my drift car). Rad is about 6 1/2 times the thickness of the stock rad so its a monster, Fans were hard wired on to a switch so i can turn them on and off as i want. Everything put back together, no leaks , fans work etc etc so all good. Problem is when idling and not moving the temp can be just below half and the heating is pumping out cold air, even when crusing around about 10-25 mph its still cold. Get the car up to 40+ and it gets warmer and the faster you go the hotter it gets. The engine temp stays just below middle on a run with or with out the fans on and when idling for 25 mins stationary without the fans on the temp got to about half maybe just over, fans get turned on and it stays at half. Now sometimes if im on the mway its fine, temp is normal, heating is hot and as im coming off in to residentual parts i flick the fans, heating still hot and as i start to slow down i can feel the heating getting cooler, then it goes ice cold and the temp goes high very quickly even with the fans on ( about 3/4 at least but never over the hot mark ) yet if i start the car from cold leave it for 30-40 mins the air is always cold and the temp doesnt go over half even with fans off. We ( meanign myself and DriftMoto, mates garage ) had bled the system about 8 times now in varius ways that we found all over the internet - fill with water - fill with water with bleed valve open - fill with front of car jacked up in air - filled with front jacked up, engine on, bleed valve off and constant stream of water - filled with front jacked up, engine off, bleed valve off and very very slowly pouring water in to system until over flowing from bleed valve and then drop car down and top up at rad - all the above done hot and cold, over flow full and empty ( no idea how this would make a difference but it seems the americans recon u have to have it full !!!?!?!?!?!? ) today i drove it and just undid the bleed valve and some air came out but after that it will get warm on idle then go cold a few minates later Now im thinking its either STILL air in the system but cant see it taking/being this hard to get rid of it would a dodgy thermostat and/or water pump give these symptoms Regarding if its a possible HG issue i can confirm 99% correct that its not using water, no smoke on idle, no smoke on start up or driving, no sludge in the rad cap and the system isnt getting pressureized so ?????????????????????????? im so stuck and fed up Quote Link to comment Share on other sites More sharing options...
M13KYF Posted October 6, 2011 Share Posted October 6, 2011 dicky thermostat? I known someone having the thermostat installed upside down which caused odd results but not on a Zed Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 not sure. need to take it out and stick it in a pan on the stove to see if its working. Its just random that its getting hot when driving let cold when not and its not like it graduallt gets old it literally takes a couple seconds after going for 60 to parks. Its almost like the water pump is only working when the rear wheels are moving fast ?!!?!?!? Quote Link to comment Share on other sites More sharing options...
M13KYF Posted October 6, 2011 Share Posted October 6, 2011 is the belt to the pump loose Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted October 6, 2011 Share Posted October 6, 2011 is the belt to the pump loose Pump is chain driven Quote Link to comment Share on other sites More sharing options...
M13KYF Posted October 6, 2011 Share Posted October 6, 2011 is the belt to the pump loose Pump is chain driven i thought it might be but wasnt sure with the timing belt being chain Quote Link to comment Share on other sites More sharing options...
glrnet Posted October 6, 2011 Share Posted October 6, 2011 I read somewhere about air in the heater core, I'll see if I can find it Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 cheers for the help guys and gals forgot to say that its only been doing this since the rad change yesterday, before that its never done the cold air whilst stationary before. Seeing as the rad is so much bigger and the water pump us chain driven could the extra volume of water be putting a strain on it when its on idle ??? Quote Link to comment Share on other sites More sharing options...
glrnet Posted October 6, 2011 Share Posted October 6, 2011 Does this make sense then:- No load + fan + cold = insufficient load for the bypass to the heater core to open. The car keeps the heater core bypass closed to keep the engine warm and to allow it to warm up the engine to the proper operating temperature faster. Maybe made worse now that you have so much more water to keep warm Quote Link to comment Share on other sites More sharing options...
stubzie83 Posted October 6, 2011 Share Posted October 6, 2011 I had this issue when I changed my coolant. It was air trapped in the heater core. It is a pig to get it out. I found that jacking the front of the car up allowed the coolant to get into the heater core and forced the air back into the radiator and then it came out through the rad cap. Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 does make sense but surely after a 1 hour blast down the m25 sitting at 70 should get the therostat open and keep the temps up and water circulating ? in my skyline i didnt have a thermostat and would be the opposite, cooler air would blow out when on the motorway as the cooling system would be getting more air and keeping things cool then as i slowed down and had less air coming in the heating would before hot... that makes sense but the 350 doesnt Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 I had this issue when I changed my coolant. It was air trapped in the heater core. It is a pig to get it out. I found that jacking the front of the car up allowed the coolant to get into the heater core and forced the air back into the radiator and then it came out through the rad cap. Cheers Stub, we did that a few times with and with out the car on and/or underload but i guess i have to keep doing it Quote Link to comment Share on other sites More sharing options...
stubzie83 Posted October 6, 2011 Share Posted October 6, 2011 Yeah youhave to get the rad cap level above the level of the air bleed plug at the back otherwise the back pipe that goes into the heater core never gets full up with coolant. You need to find a way of filling up from the rad cap until coolant comes out of the air bleed plug before the rad is full up. If you do it with the car level then the rad fills up before it comes out of the bleed plug and you then have trapped air. It can be a very painful process trying to get rid of it. Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 tell me about it. I guess i'll be trying it again tonight. Someone on Driftworks said i have to have it so there is hot air coming through the vents in order for this to work as that means there is cooland in the system. Is that right or can i just have the front jacked up when its cold and do it ? Quote Link to comment Share on other sites More sharing options...
stubzie83 Posted October 6, 2011 Share Posted October 6, 2011 You'll only get hot air out once the air is out of the heater core. If you bleeding the air with the engine on then set the heaters to max. The vent air will start to get warm as the air comes out of the heater core. Be careful leaving the air bleed open whilst running though as when the air is out the coolant will be pissing out of the plug. Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 yeah i have a spare set of hands lol, one manning the bleed and one pouring in the coolant that way when its flowing out the bleed constantly and no bubbles i can block it up and then the rad and get topped out and cap on. cheers for the help everyone. Another issue is im so bloody paranoid of it over heating now hahahah Quote Link to comment Share on other sites More sharing options...
Ebized Posted October 6, 2011 Share Posted October 6, 2011 Picking up from what glrnet said, perhaps the advice in this thread and that by ZMANALEX might help? viewtopic.php?f=10&t=23104&hilit=heater+core&start=0 Quote Link to comment Share on other sites More sharing options...
glrnet Posted October 6, 2011 Share Posted October 6, 2011 Thanks Colin, that was what I read before and couldn't find it, I mentioned it earlier in this thread. Picking up from what glrnet said, perhaps the advice in this thread and that by ZMANALEX might help? viewtopic.php?f=10&t=23104&hilit=heater+core&start=0 Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 6, 2011 Author Share Posted October 6, 2011 Thanks guys very helpful One step I have no idea how it would help is filling the over flow bottle up !!! I mean it's just that, an over flow bottle. I didn't think the rad could suck water In from the bottle as the cap acts like a one way valve sort Of thing Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 12, 2011 Author Share Posted October 12, 2011 OMG finally fixed it. Its now over cooling thanks to the massive ( in comparison to the stock rad ) alloy rad and twin fans !!! but im getting warm/hot air while stationary and moving. Ended up bleeding it about 6 more times using the "get a massive bottle, wedged in to the rad and keep pouring stuff in till all air is out" method. Still had the same issue only now a new issue of the top hose was getting mighty hot and rock solid and the lower hose was still cold !!! With that i knew the thermo must be shot so took it out, stuck it in a pan on the stove with boiling water and it barely opened. GREAT !!! its sunday, no one is open and i need the car for monday morning. Now i would like to thank nissan for making it have one way screws so you cant get the thernostat off the housing easily. Thats when i went all match.com and found my thermo a new mate, Mr Grinder. Anyway i cut the thermo off the housing, re-installed, bled it a few more times and hey presto its all good. Even when sitting in traffic ( after a 20 minate drive on the motorway) the temp doesnt go over half and thats without the fans on (hard wired on a manual switch now ). With the fans on and whilst driving it barely gets over 1/3 of the way which im fine with as it means its keeping nice and cool. Just means the heating never gets hot but only comfortably warm. finally can drive my car without having to plan everything around traffic Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 12, 2011 Share Posted October 12, 2011 does anyone have a definative guide on how to bleed the rad and which coolant should be used. Im going to need to take my radiator off for my lightweight pulleys. Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 12, 2011 Author Share Posted October 12, 2011 After near on 20 attempts this is thee one that worked perfectly for me http://www.driftworks.com/forum/technic ... issan.html I just used shell anti freeze as it was a Sunday an nothing was open Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 12, 2011 Share Posted October 12, 2011 After near on 20 attempts this is thee one that worked perfectly for me http://www.driftworks.com/forum/technic ... issan.html I just used shell anti freeze as it was a Sunday an nothing was open cheers mate did you take any pictures on how to remove the rad? Quote Link to comment Share on other sites More sharing options...
cefiro_drifter Posted October 12, 2011 Author Share Posted October 12, 2011 Na I didn't but it's easy tbh Remove Two locking tabs on the top In the front of them are two plastic covers hiding two 10mm bolts which hold the AC rad to the normal rad Take both hoses off Take air box off Take plastic engine cover off Lift rad out with fans but remember to unclip the wiring It's a lil tricky to get back in but only coz te AC rad likes to flop around lol Quote Link to comment Share on other sites More sharing options...
Dblock Posted October 12, 2011 Share Posted October 12, 2011 cheers mate Quote Link to comment Share on other sites More sharing options...
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