Sparky Posted October 1, 2006 Share Posted October 1, 2006 Well, I went out to tune the Zed sled today and ran into my second little issue with the car since I got it running. After a few minutes of running and tuning for idle I noticed the water temp indicator on the haltech was in the red....reading 210 and rising. I turned on the electric fan and it kept going up till about 220 when I shut it off. I let her cool down and tried again this time with the fan running from 190....same results. So I pull off the cap and put my hand on the radiator to find it was cool to the touch well, I left the cap off and started the car again and watch the water level drop about an two inches...indicating that the water pump is trying to pull water up in the block, I topped it off and when I shut it down it puked all the water i put in out the filler neck..AIR POCKET! Well, I jacked the car up from the front and fiddled with the hoses with no luck, jacked it up from the rear and tried to force the pocket out with no luck This is the first time I've ever had problems with air in the cooling system on a Z car, coincidently I recently installed a AFCO alum. radiator and had to engineer some new hoses.... So I come here today for advice, and a recomended plan of attack... opinions? Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted October 1, 2006 Share Posted October 1, 2006 hoses run wrong or left a plastic dirt cap in the radiator. I've never seen an engine that is so designed that air doesn't just go out. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 2, 2006 Share Posted October 2, 2006 The best way is to jack the nose of the car as high as possible on a hill! And place a plastic funnel in the neck of the radiator and have the car running for 15+minutes of so, you want to do it do the t-stat opens and closes a few times. I always hate purging air from the cooling system - pain in the butt! Good luck Yasin Quote Link to comment Share on other sites More sharing options...
Gavin Posted October 2, 2006 Share Posted October 2, 2006 I worked at a Toyota dealership for a while and we always used the funnel method as Yasin mentioned. They actualy make special buckets for doing this, which have a special radiator cap for sealing it to the radiator. This way you can fill the bucket, warm it up, and wait for it to stop bubbling. You would be suprised how many bubbles still appear even after maybe 10 minutes of this. - At home I usually just leave the cap off, warm it up, and keep topping it. Dont think its as effective since the water level is lower. Try purging an MR2! Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted October 2, 2006 Share Posted October 2, 2006 Check the thermo. If it's not operating properly you will get the exact senario you discribed. Otherwise start the engine cold with the cap off and run it untill you get flow. Not just a level drop, actual flow. Fill and flow (the thermo will slam shut if it gets a taste of the cold water) untill about an inch from the top. With the fan on it should not overheat. Once stable then cap it and run it for awhile. The temp should drop some once it gains pressure. I have always used this method with no probs. I would be eyeballing the thermo..... Quote Link to comment Share on other sites More sharing options...
MikeJTR Posted October 2, 2006 Share Posted October 2, 2006 You should also check the small bypass hose on the thermostat housing. If it is plugged, the thermostat won't receive hot coolant, and it can cause the problem you described. If you have removed the bypass hose, then you need to drill a small hole in the thermostat to allow some coolant flow through the thermostat housing so the thermostat can receive engine coolant. Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 2, 2006 Share Posted October 2, 2006 I have purged and MR2...Never ever ever again. That is the most rediculous system ever. Quote Link to comment Share on other sites More sharing options...
Sparky Posted October 2, 2006 Author Share Posted October 2, 2006 The best way is to jack the nose of the car as high as possible on a hill! And place a plastic funnel in the neck of the radiator and have the car running for 15+minutes of so, you want to do it do the t-stat opens and closes a few times. I always hate purging air from the cooling system - pain in the butt! Good luck Yasin I wish I had a hill available..but even if I did I cant even drive the car, and the local neighborhood association is full of busy body weenies I will try the funnel method though...am I understanding that you just place the end of the funnel in the filler neck and thats it? I worked at a Toyota dealership for a while and we always used the funnel method as Yasin mentioned. They actualy make special buckets for doing this, which have a special radiator cap for sealing it to the radiator. This way you can fill the bucket, warm it up, and wait for it to stop bubbling. You would be suprised how many bubbles still appear even after maybe 10 minutes of this. - At home I usually just leave the cap off, warm it up, and keep topping it. Dont think its as effective since the water level is lower. Try purging an MR2! I was looking for a specialty tool thats made specifically for purging cooling systems, its like a radiator cap with a small container attached that you fill with water and then compress with an air compressor...I'm i crazy or does something like this excist? I would be eyeballing the thermo..... Brand new Nissan thermo, and I removed the thermostat thinking that it was the problem (('ve had new ones go bad) but the problem persists... You should also check the small bypass hose on the thermostat housing. If it is plugged, the thermostat won't receive hot coolant, and it can cause the problem you described.If you have removed the bypass hose, then you need to drill a small hole in the thermostat to allow some coolant flow through the thermostat housing so the thermostat can receive engine coolant. It never had a hose just a port plugged up..(so thats what goes there!)but I have the run this same housing setup in the past on multiple Z's with no problem. I'm wondering if the thermostat wasnt getting coolant and that caused a steam pocket to develop in the engine that wouldnt allow it to build pressure and pump. it seems unlikely to me, but i will check into that later tonight when I go to work on it. Is there a post or site that describes the drilling of the T-stat? I will search later, but if you know it off had that would be helpful. I'm hoping that its not my new radiator and hose routing causing the problem, I've done this so many times in the past though on all kinds of cars with no problems... o-well, just another bump in the road. thanks everyone for the suggestions. Hopefully I will have a positive update tonight. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted October 2, 2006 Share Posted October 2, 2006 Brand new Nissan thermo, and I removed the thermostat thinking that it was the problem (('ve had new ones go bad) but the problem persists... Wow is that car a Devil Z? If the thermo was pulled you should have raging flow but the engine would slowly get warmer and warmer and over time eventually overheat or run on the high side all the time. Are you sure that you have impellers on the water pump? Blocked flow of any kind? It seemed classic a case of no flow. Heat builds in the engine and the resultant steam pushes the water in the lines and tank out. Believe it or not, I once installed a pump on a 396. dicked with the system for a couple of days. Same stuff you are going through. Pulled thermo and the like. Still barfed up after five minutes of run. finally broke down pulled everything apart. I stared in pure disbelief at the bare impeller shaft. No impeller was installed when it was rebuilt!! Replaced the pump, viola! Keep us posted on this one, should be interesting! Quote Link to comment Share on other sites More sharing options...
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