Indigent Posted March 3, 2008 Share Posted March 3, 2008 I have no circulation in my coolant system. The water pump was installed a few months ago on the last t-belt change. I have had the heads off to change a head gasket and valves. I have just finished putting it back together, and now there is no circulation. I am pretty sure I have some lines in the wrong place somewhere, but I can't find any actual pictures of where they are supposed to go. There is a good one for the vacuum lines, but anyone know of one for the coolant? I guess I could always resort to cross-checking with another good engine, but thought I would check here first. thanks Indigent. Link to comment Share on other sites More sharing options...
mws Posted March 3, 2008 Share Posted March 3, 2008 No diagram handy, but a couple questions to verify - - Did you crack open the bleed screw? - Did you let it warm up fully? Until the engine gets to temp, the thermostat will remain closed and you will see very little to no circulation in the radiator. Once the temp gauge gets to middle of scale, then the thermostat should open and you will see movement in radiator. Link to comment Share on other sites More sharing options...
94extreme Posted March 3, 2008 Share Posted March 3, 2008 or the pump is shot. the only time i had no circ is when my heater core froze.. i even overheated when it was well below 0F. Link to comment Share on other sites More sharing options...
Indigent Posted March 4, 2008 Author Share Posted March 4, 2008 No diagram handy, but a couple questions to verify - - Did you crack open the bleed screw? - Did you let it warm up fully? Until the engine gets to temp, the thermostat will remain closed and you will see very little to no circulation in the radiator. Once the temp gauge gets to middle of scale, then the thermostat should open and you will see movement in radiator. Yes I did crack the bleed screw. It warmed up fully, and then started to overheat. Is there a way to start the pump manually to verify it's operation? Like I said though, I am pretty sure I have a coolant line on wrong or something simple, but there doesn't seem to be any info on it. A buddy of mine from work has a 91 truck with a vg30e in it, so I am going to take some pics of his engine and cross-check them with how mine is setup now. Hate to say it, but I actually hope I find something wrong. hehe. Any other ideas? thanks. Indigent. Link to comment Share on other sites More sharing options...
mws Posted March 4, 2008 Share Posted March 4, 2008 Yeah, a couple other ideas - 1) You do have the belts on and adjusted, right? 2) If the thermostat was inserted backwards, it will not open. It needs to be installed so the big brass blob is towards the engine side - upwards and to the right on the VG. You would not be the first to install backwards. Chevy guys think all go in with blob down. Not on VG. Blob goes toward engine side. 3) And if you did not change the thermostat, it could very possibly be stuck closed after sitting so long. 4) If you change thermostat and used silicone to seal the housing, and used quite a bit to be sure it sealed, the excess would have squeezed inside the housing and effectively glued the thermostat closed. If you use sealant, use only a thin film. 5) It is possible for a new water pump to not work. But highly unlikely. You can remove the alternator belt and should be able to spin the water pump pully by hand. There should be some resistance as the impeller tries to move water. And as far as engine coolant flow, it is pretty simple: One big hose coming off the bottom passenger side of pump (thermostat housing) into the steel pipe and down, then into bottom of radiator. One big hose going from top of engine to top of radiator. The smaller right angle bypass line. That's it for engine coolant flow. There are a few other hoses related to heater and maybe TB, but even if those are misrouted, the engine would not overheat. Link to comment Share on other sites More sharing options...
racerdave Posted March 4, 2008 Share Posted March 4, 2008 Sounds to me like you have a stuck thermostat, and possibly air in the lines... When u crack the bleed screw, does any coolant come out? Link to comment Share on other sites More sharing options...
Indigent Posted March 4, 2008 Author Share Posted March 4, 2008 Sounds to me like you have a stuck thermostat, and possibly air in the lines... When u crack the bleed screw, does any coolant come out? none comes out just from removing the screw, but if I squeeze on the upper radiator hose some does come out. If the thermostat is stuck, how do I un-stick it? Like I said, I have never had a coolant issue on this before I pulled everything apart. I can feel that resistance on the water pump impeller when I rotate it, so I assume the pump is OK. Is there something else I am missing? I filled it up with the engine cool and then cranked it and filled it some more. None is leaking out, there is just no flow. indigent. Link to comment Share on other sites More sharing options...
94extreme Posted March 4, 2008 Share Posted March 4, 2008 any kinks and such? what else did you disassemble besides the front to do the t-belt? i'm thinking the thermo too if everything else is the way it's supposed to be on the outside. Link to comment Share on other sites More sharing options...
Indigent Posted March 4, 2008 Author Share Posted March 4, 2008 Well, I had both heads off and everything else that goes along with head removal. I did not take the thermostat out. no visible kinks or any other hose damage. indigent. Link to comment Share on other sites More sharing options...
mws Posted March 4, 2008 Share Posted March 4, 2008 From all you described here, I would start with replacing the thermostat. Not a pleasant job, I know. But it is the most likely suspect. They are cheap and a new one will resolve any stuck issues. Taking the time to remove the belts, cooling fan pulley, and outer timing belt cover is well worth it as it will save you time getting the new thermostat in. With everything in place it is a royal pain to get it done. The thermostat will not want to stay up in the hole due to that gravity thing. I put a couple LITTLE dabs of silicone on the flange and hold it in place with tape for about 1/2 hour (beer break) to more or less glue it in place. I've installed the thermostat cover with gasket and with just silicone (SMALL bead) and all have sealed up dandy. Do not overtorque the cover - it will warp and leak. Link to comment Share on other sites More sharing options...
GrimGreg Posted March 4, 2008 Share Posted March 4, 2008 Stupid question first, you do have a belt running to the pump pully right? If it isn't the thermostat, then maybe you used the wrong head gaskets or somehow otherwise blocked a water passage in the heads when you had them off? Link to comment Share on other sites More sharing options...
Indigent Posted March 5, 2008 Author Share Posted March 5, 2008 Well, For the last few days I have just said screw it. I finally went out there today and the radiator was low so I put some more coolant in, and it just started circulating. I guess there was just some air trapped or something. I literally didn't to anything to fix it! I love it when that kind of stuff happens. Thanks for all of the suggestions. Indigent. Link to comment Share on other sites More sharing options...
94extreme Posted March 6, 2008 Share Posted March 6, 2008 I literally didn't to anything to fix it! I love it when that kind of stuff happens.lol.. i love that too.. my injectors fixed themselves here not long ago. Link to comment Share on other sites More sharing options...
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