ggzilla Posted February 10, 2012 Report Share Posted February 10, 2012 There is no "priming" possible or needed. Difference is this time the upper and lower hose are soft like there is no coolant in them Also impossible. The lower hose will always have water in it if the radiator is full. The upper hose may go dry if there is an air bubble. What you feel may be an air pocket which is compressible. It needs more than 10 minutes, and possibly more the 20 if the weather is cold. Top it up & run until the engine gets warm. If that doesn't resolve it, time to test the new thermostat again. It might have failed already. Quote Link to comment
Eagle_Adam Posted February 10, 2012 Author Report Share Posted February 10, 2012 What you feel may be an air pocket which is compressible. It needs more than 10 minutes, and possibly more the 20 if the weather is cold. Top it up & run until the engine gets warm. If that doesn't resolve it, time to test the new thermostat again. It might have failed already. it opens it closes and yet I double checked the thermostat again and finally got the air out of the system but the gauge still reads cold. Im going to stop by a friends place on the way to work and check the thermostat housing with a laser temp gun. Im starting to think my testing of the gauge was faulty Quote Link to comment
ggzilla Posted February 10, 2012 Report Share Posted February 10, 2012 This is not reading Cold: Cold is to the left of the first lines. You might have said it is "reading colder than it used to". That reading is perfect for a 170 thermostat. Quote Link to comment
Eagle_Adam Posted February 10, 2012 Author Report Share Posted February 10, 2012 This is not reading Cold: Cold is to the left of the first lines. You might have said it is "reading colder than it used to". That reading is perfect for a 170 thermostat. i said cold because i checked the thermostat housing with a lazer temp gun once before and it read did this and the block reads 145 and the thermostat housing reads 135 :blink: i checked it again this morning after driving for 10 miles or so and the readings were 145 at the top of the thermostat housing 160 at the bottom Quote Link to comment
ggzilla Posted February 11, 2012 Report Share Posted February 11, 2012 Aw, it read 145 on the laser guage. So what's next? Quote Link to comment
Eagle_Adam Posted February 12, 2012 Author Report Share Posted February 12, 2012 a friend of mine has a 150 thermostat so im going to swap it in later tonight to see if it makes a difference. I know its not right and the motor need to be around 170 to properly operate properly but its the easiest thing to try right now with out spending $$ on it. I tested the gauge again and its functioning properly. I also tossed some cardboard in front of the radiator to see if i could get the temp up but no luck. Quote Link to comment
ggzilla Posted February 12, 2012 Report Share Posted February 12, 2012 It will operate properly at 150 or even 145. It just won't be as efficient. EFI cars usually won't run correctly at that temperature, because they are expecting different sensor readings. Quote Link to comment
datzenmike Posted February 12, 2012 Report Share Posted February 12, 2012 the thermostat did have a small hole with what looked to be a "brass pin" in it - like this one vvv It's called a jiggle valve and allows air bubbles out and to a certain extent alows water to circulate past the thermostat. Not really needed on the L series as they have a by pass hose for that. and yet I double checked the thermostat again and finally got the air out of the system but the gauge still reads cold. Im going to stop by a friends place on the way to work and check the thermostat housing with a laser temp gun. Im starting to think my testing of the gauge was faulty As stated this is normal on my Datsuns about a third of the way up the run range. i said cold because i checked the thermostat housing with a lazer temp gun once before and it read i checked it again this morning after driving for 10 miles or so and the readings were 145 at the top of the thermostat housing 160 at the bottom Have to say that with a new thermostat and a gauge that is reading properly it doesn't mater what the lazer gun reads... maybe it's no good. Shoot a pot of boiling water and see what it says. Bottom line is there heat from your heater???? Are the rad and heater hoses hot to the touch??? Seems like everything is working fine. Quote Link to comment
Eagle_Adam Posted February 12, 2012 Author Report Share Posted February 12, 2012 It will operate properly at 150 or even 145. It just won't be as efficient. EFI cars usually won't run correctly at that temperature, because they are expecting different sensor readings. Good to know It's called a jiggle valve and allows air bubbles out and to a certain extent alows water to circulate past the thermostat. Not really needed on the L series as they have a by pass hose for that. Do you remove the jiggle valve ? or specifically ask for one with out a jiggle valve? As stated this is normal on my Datsuns about a third of the way up the run range. The reason im thinking there is an issue is because prior to parking the truck for about 3 months the gauge always went to half way Have to say that with a new thermostat and a gauge that is reading properly it doesn't mater what the lazer gun reads... maybe it's no good. Shoot a pot of boiling water and see what it says. I will check the thermal gun next time i can go over to his house. i had not wondered if is calibrated properly Bottom line is there heat from your heater???? Are the rad and heater hoses hot to the touch??? Seems like everything is working fine. Yes there is heat from the heater, the radiator hoses are warm at best, i have touched them prior to this issue and remember them being somewhat uncomfortable to touch and they are not like that right now. This is my reasoning for getting a lower temp thermostat, trying to see if there is a difference. If there is i would assume the system is indeed not getting warm enough. Not sure if im right but i figured i wasn't going to hurt anything so why not. Quote Link to comment
Eagle_Adam Posted February 13, 2012 Author Report Share Posted February 13, 2012 got the 150 thermostat put in and this was the results am i wrong to think that since a lower temp thermostat lowered the temp on the gauge that a higher temp one would raise the temp on the gauge? Quote Link to comment
ggzilla Posted February 13, 2012 Report Share Posted February 13, 2012 Sure, that's what we were trying to tell you. If you want it hotter, put a hotter thermostat in. When you test it in the pot of water, use a cooking thermometer. Verify it opens at the specified temp (180-stat starts opening at 177, fully open by 183). Quote Link to comment
Eagle_Adam Posted February 13, 2012 Author Report Share Posted February 13, 2012 sometimes i just dont get it the first time. Thanx ggzilla for your continued help, im going to get a new thermostat tomorrow and see how it goes. Quote Link to comment
Eagle_Adam Posted February 14, 2012 Author Report Share Posted February 14, 2012 new 190 thermostat installed - still reading the same but i noticed there is air in the system again. Going to try an jack up the front and and run it to see if i burp the system. Quote Link to comment
datzenmike Posted February 14, 2012 Report Share Posted February 14, 2012 Did the thermostat have a tiny hole in it, to allow air to bleed past it when filling the cooling system? Make sure the heater valve is also turned on when filling the cooling system. If you did not have the hole in the thermostat, one solution is to get the engine warm, so the thermostat opens, and then the air can get past it. Or remove the thermostat, and drill a small (1/16) hole in the plate. THIS Air will work it's way up and out the top rad hose as it's pretty much the highest point. If you have a juggle valve the air will self bleed as you fill it. Any air perhaps in a heater hose will move once the water pump starts working and will exit the rad once the thermostat opens. You don't have to park on an incline, just check the rad level every time you start it up cold and top up. Quote Link to comment
Eagle_Adam Posted February 14, 2012 Author Report Share Posted February 14, 2012 How long should it take to burp the air out? I drove for 5 miles or so last night and 10 miles or so on the way to work this morning and the upper and lower hoses are still soft which leads me to believe that air is still in the system. Quote Link to comment
datzenmike Posted February 14, 2012 Report Share Posted February 14, 2012 Soft means nothing. When cold open the rad cap, if there is room for more water, fill it up. Leave an inch for expansion. Quote Link to comment
Eagle_Adam Posted February 14, 2012 Author Report Share Posted February 14, 2012 they are soft even when the motor is running. I have checked the rad every time before driving. No room to fill it Quote Link to comment
datzenmike Posted February 14, 2012 Report Share Posted February 14, 2012 Then good to go. You put a 180? was it? thermostat back in. Heater works and gauge reads between 1/3 to 1/2? in the RUN RANGE That's where mine run. Quote Link to comment
Eagle_Adam Posted February 14, 2012 Author Report Share Posted February 14, 2012 no, there is a 190 in it right now and its barley in the run range Quote Link to comment
Lee R Posted February 14, 2012 Report Share Posted February 14, 2012 My gauge reads the same as yours and I have a 180 therm. in it. On the hottest days it may go a little over half way. I think you are are good to go. Quote Link to comment
Eagle_Adam Posted February 14, 2012 Author Report Share Posted February 14, 2012 Mkay, im done with this issue, thank you to everybody who helped out. too many other things to work on. Its just weird that before i parked the truck for repairs that gauge always went to half. :unsure: Quote Link to comment
ggzilla Posted February 15, 2012 Report Share Posted February 15, 2012 My radiator hoses are soft after two years of driving. Doesn't really mean anything. My other datsun has hard hoses, i think they need replacing. What I have found in the last 29-1/2 years of driving a Datsun is to let if warm up fully, drive it for a many miles, then let it cool down fully. That means overnight. Then top it up before you go. And even when there is air in the system, the dash temp gauge still works. It shouldn't read low just because there is a little air in the system. Use a third temp gun/guage to check out which of the other two are wrong... Quote Link to comment
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