Bigsyke
06-19-2009, 08:00 PM
So after yesterday, I have officially refilled/rebled my cooling system for the 10th time this season. I have nailed it down to a T.
Lets start with the basics, im sick of seeing these overheating threads, when its actually quiet simple- aside from a cracked block/leaky HG.
~Bleeding the system. 9/10 times I bleed the system, I could not get the airbubble out of the front cover (thermostat) the 1st shot. By 1st shot I mean untill the Coolant temp sensor trips Cooling fan Relay #1 @ 203*f. So for the poor basic people W/O a nice little swirl tank, the obvious is jacking the front end up, with the heater setting fully on the hot side. I even went to push the lever down some more in the engine bay. IMO Loosening the upper heater core neck by the lever is point less since the air will still end up slightly higher than that. I wouldnt usually start this process untill I have one of these. http://www.denlorstools.com/shop/images/LIS-22150_LG.jpg
They are $29.99 on ebay, and I even found one at napa. Buy it now.
Go ahead and loosen the upper Radiator hose by the radiator and the lower radiator hose by the thermostat cover. The thermostat cover is probably the most important since the Jiggle valve should eventually bleed some air into the thermostat housing, which can ONLY be releived by loosening the lower radiator hose, or by the thermostat opening fully. The Thermostat will NOT open if you have an air bubble in the front cover, and if its big enough it can only be relieved by loosening the lower rad hose, and bleeding some out.
So to bleed, install the fill funnel, have the lower radiator hose detached or loosened to bleed air while you fill. Slowly pour the coolant so it can allow air to excape. For those who think the FSM can get the air out think again, get one of these snap-on fill funnels and watch the bubbles rise like a hot tub. I dont have a bleeder bolt, mine snapped and IMO i think its useless with the snap-on funnel.
Once you at least get the initial air pocket out of the thermostat housing continue to fill up untill coolant is about 3/4ths to the top of the funnel. Start messaging hoses to assist some removal of bubbles before starting the car. Once the car is started keep an eye on everything, massage some hoses to assist air removal. The funnel is key on removing bubbles since it uses gravity to accomplish an air free system.
Once/if the thermostat opens up you will see alot of activity. The thermostat cover should be HOT to the touch. If the OE A/C fans should come on @ 203*f, and the lower T-stat housing is semi warm, or the lower hose is cool shut the car down asap. This is very important to see if you have fully removed the air in the front cover, so the thermostat can open - What I do is keep the funnel full, take a screw driver and slowly loosen the lower hose at the t-stat cover. Take the flathead screwdriver adn slowly pry some of the hose up to slowly release some air. Start squeasing hoses to circulate some trapped air and release some air again. Reinstall hose and start engine. Once the lower t-stat cover gets hot, you have sucessfully bled the main air pocket from the system. Keep the engine running at idle with NO heater fan on untill the OE cooling fan relay #1 comes on. This is important to note how long its on for. If its on for longer than 8-10 seconds you have air in front of the T-stat, and its not circulating. This is probably different if you have a clutch fan, I have altima fans, but the idea is the same.
You can fully get the air from the system, but the bad news is it will keep comming back, and only get worse with time. This is where the 2nd best purchase of your life comes. The D-max breather/swirl tank. http://gtfactory.jp/cms/maxcat/ubt/large/P1020622.jpg
This makes bleeding even easier, however you still need to remove that initial front air pocket from the t-stat housing cover. After that, its straight forward. Since our nissans dont have an NPT port next to the bleeder bolt, you need 2x 34mm rad hose adaptors ($20 each from dan max). 1 goes in the lower, one the upper. The Throttle body fittings do NOT work, ive tried and I couldnt get the system bled. I did notice with the breather setup, I still had a collection of air by the upper radiator neck (mine is a mishimoto, the upper rad neck is raised). This is not to worry since ALL air in the system will eventually end up in the swirl tank. I would not run a Z32 cap or anything higher than 1.1 because the silicone hoses IMO suck, mine after a few days are starting to tear at the clams. So I would reccomend getting some Stainless worm clamps and use a box wrench to tighten them down to maybe 3lbs/ft. Practice on a spare fitting, see how much it takes to mangle a worm clamp, you want these tight, because after your done, your going to pressure test teh system. You would be supprised how tight you need these to hold 19lbs for 15+ minutes.
Do not daily drive your car untill you have pressure tested your system, and you can hold at least 17-19lbs for about 10 minutes. Good time to check for leaks. Leaks cause air bubbles, airbubbles end up at the thermostat, thus overheating the engine.
~ Thermostat. Im a huge advocate of the nismo/sard. Its not a waste, and no your engine WONT run at 150*f, Thats when the thermostat starts to open. IMO once you get to know your cooling system, it just begs for a 150*f t-stat, esp if your not running a clutch fan, and have an aluminum radiator. This will also save your hoses. Clipping your jiggle valve actually reverses what you want. A quick warm up, and for it to stabilize within opperating range. I believe a clipped jiggle valve takes 2x to warm up, and causes a lazy thermostat. I dont think the ECT sensor will richen the fuel mixture with a sard/nismo.
~ coolant. Honda type II, nuff said. Its organic, and has been known to increase surface tension. Water wetter needs to be changed every season, I try to stay away. Do not run straight water/WW, unless you like air pockets and osmosis, slowly eating away at your aluminum radiator and head.
Use a clear silicone hose from home depot to connect to your overflow, use hose clamps too, I noticed this is important because if you have any loose connections here it will not draw coolant back into the radiator. Also cap those coolant lines dont loop them, they always tend to trap air there, its not needed. Ive ran capped TB lines in -20*f weather.
IMO I would ditch the OE radiator for one reason, the platic end caps. You want to use stainless worm clamps to secure the hoses, I am one of the many who have broken the upper radiator neck, and over heated the engine. I got a mishimoto for $225, and it was worth every penny. This is why I then recommend the nismo thermostat, because the all aluminum doesnt seem to be as efficient as the OE copper.
Lets start with the basics, im sick of seeing these overheating threads, when its actually quiet simple- aside from a cracked block/leaky HG.
~Bleeding the system. 9/10 times I bleed the system, I could not get the airbubble out of the front cover (thermostat) the 1st shot. By 1st shot I mean untill the Coolant temp sensor trips Cooling fan Relay #1 @ 203*f. So for the poor basic people W/O a nice little swirl tank, the obvious is jacking the front end up, with the heater setting fully on the hot side. I even went to push the lever down some more in the engine bay. IMO Loosening the upper heater core neck by the lever is point less since the air will still end up slightly higher than that. I wouldnt usually start this process untill I have one of these. http://www.denlorstools.com/shop/images/LIS-22150_LG.jpg
They are $29.99 on ebay, and I even found one at napa. Buy it now.
Go ahead and loosen the upper Radiator hose by the radiator and the lower radiator hose by the thermostat cover. The thermostat cover is probably the most important since the Jiggle valve should eventually bleed some air into the thermostat housing, which can ONLY be releived by loosening the lower radiator hose, or by the thermostat opening fully. The Thermostat will NOT open if you have an air bubble in the front cover, and if its big enough it can only be relieved by loosening the lower rad hose, and bleeding some out.
So to bleed, install the fill funnel, have the lower radiator hose detached or loosened to bleed air while you fill. Slowly pour the coolant so it can allow air to excape. For those who think the FSM can get the air out think again, get one of these snap-on fill funnels and watch the bubbles rise like a hot tub. I dont have a bleeder bolt, mine snapped and IMO i think its useless with the snap-on funnel.
Once you at least get the initial air pocket out of the thermostat housing continue to fill up untill coolant is about 3/4ths to the top of the funnel. Start messaging hoses to assist some removal of bubbles before starting the car. Once the car is started keep an eye on everything, massage some hoses to assist air removal. The funnel is key on removing bubbles since it uses gravity to accomplish an air free system.
Once/if the thermostat opens up you will see alot of activity. The thermostat cover should be HOT to the touch. If the OE A/C fans should come on @ 203*f, and the lower T-stat housing is semi warm, or the lower hose is cool shut the car down asap. This is very important to see if you have fully removed the air in the front cover, so the thermostat can open - What I do is keep the funnel full, take a screw driver and slowly loosen the lower hose at the t-stat cover. Take the flathead screwdriver adn slowly pry some of the hose up to slowly release some air. Start squeasing hoses to circulate some trapped air and release some air again. Reinstall hose and start engine. Once the lower t-stat cover gets hot, you have sucessfully bled the main air pocket from the system. Keep the engine running at idle with NO heater fan on untill the OE cooling fan relay #1 comes on. This is important to note how long its on for. If its on for longer than 8-10 seconds you have air in front of the T-stat, and its not circulating. This is probably different if you have a clutch fan, I have altima fans, but the idea is the same.
You can fully get the air from the system, but the bad news is it will keep comming back, and only get worse with time. This is where the 2nd best purchase of your life comes. The D-max breather/swirl tank. http://gtfactory.jp/cms/maxcat/ubt/large/P1020622.jpg
This makes bleeding even easier, however you still need to remove that initial front air pocket from the t-stat housing cover. After that, its straight forward. Since our nissans dont have an NPT port next to the bleeder bolt, you need 2x 34mm rad hose adaptors ($20 each from dan max). 1 goes in the lower, one the upper. The Throttle body fittings do NOT work, ive tried and I couldnt get the system bled. I did notice with the breather setup, I still had a collection of air by the upper radiator neck (mine is a mishimoto, the upper rad neck is raised). This is not to worry since ALL air in the system will eventually end up in the swirl tank. I would not run a Z32 cap or anything higher than 1.1 because the silicone hoses IMO suck, mine after a few days are starting to tear at the clams. So I would reccomend getting some Stainless worm clamps and use a box wrench to tighten them down to maybe 3lbs/ft. Practice on a spare fitting, see how much it takes to mangle a worm clamp, you want these tight, because after your done, your going to pressure test teh system. You would be supprised how tight you need these to hold 19lbs for 15+ minutes.
Do not daily drive your car untill you have pressure tested your system, and you can hold at least 17-19lbs for about 10 minutes. Good time to check for leaks. Leaks cause air bubbles, airbubbles end up at the thermostat, thus overheating the engine.
~ Thermostat. Im a huge advocate of the nismo/sard. Its not a waste, and no your engine WONT run at 150*f, Thats when the thermostat starts to open. IMO once you get to know your cooling system, it just begs for a 150*f t-stat, esp if your not running a clutch fan, and have an aluminum radiator. This will also save your hoses. Clipping your jiggle valve actually reverses what you want. A quick warm up, and for it to stabilize within opperating range. I believe a clipped jiggle valve takes 2x to warm up, and causes a lazy thermostat. I dont think the ECT sensor will richen the fuel mixture with a sard/nismo.
~ coolant. Honda type II, nuff said. Its organic, and has been known to increase surface tension. Water wetter needs to be changed every season, I try to stay away. Do not run straight water/WW, unless you like air pockets and osmosis, slowly eating away at your aluminum radiator and head.
Use a clear silicone hose from home depot to connect to your overflow, use hose clamps too, I noticed this is important because if you have any loose connections here it will not draw coolant back into the radiator. Also cap those coolant lines dont loop them, they always tend to trap air there, its not needed. Ive ran capped TB lines in -20*f weather.
IMO I would ditch the OE radiator for one reason, the platic end caps. You want to use stainless worm clamps to secure the hoses, I am one of the many who have broken the upper radiator neck, and over heated the engine. I got a mishimoto for $225, and it was worth every penny. This is why I then recommend the nismo thermostat, because the all aluminum doesnt seem to be as efficient as the OE copper.