New thermostat install on swapped KA24DE, overheats quickly - how to bleeeeed

[jt1583]

Hi guys, I believe this to be an issue with bleeding the system and while I have looked through a bunch of threads about bleeding/overheating, the bleed procedure is still unclear to me.

Setup - Stock KA24DE, koyo radiator, Defi coolant temp gauge w/ sender in upper radiator hose. Boiling-water method tested thermostat, recently filled the system with ~1.5 gallons coolant.

Quick background - I swapped in a used KA24DE recently and am just trying to get this damn thing running like stock. After installing it ran good, no leaks of any sort, except it would rarely get up to temperature. 140F was normal, maybe around 170 in traffic. So I got an OEM thermo and went to replace it and found nothing to replace, so I installed it. Some idiot was running this thing thermoless. After installing and filling w/ coolant, I used the bleed procedure outlined below. However I can't drive the car more than 2 miles if it's been warmed up without my Defi reading 200+. NOT GOOD!

Ok so to bleed here is what I did
-Jack front of vehicle up a good bit
-Undo bleed screw, and rad cap. Fill system til the radiator is full - nothing came out of the bleeder hole
-Then I ran the car, after about 5 minutes I saw coolant starting to splash out of the bleeder so I closed that. A few minutes later the radiator filler started splashing pretty aggressively, so I closed that.
-After this I tried to let it run but it climbed too hot and I shut it down.
-I allowed the car to cool and tried to fill it up but the system didn't want to take much more. The reservoir become emptied once but then I filled it and it was full for good.

Am I doing something very wrong here? My CA18 was easy as pie to bleed. I have heard about squeezing the lower rad hose during this whole bleeding process and will try it. I get another opportunity tomorrow to work on the car, so any advice is appreciated.

BTW, I read in another thread that if the thermo works it can only be air bubbles causing something like this, but what about blockages? What I am afraid of is the the previous engine owner removed the thermostat because of another more serious, underlying issue and I don't want to have this be the case, obviously. When I think about the coolant system, if the pump works, and the thermo works, and the radiator isn't blocked, what can go wrong? Can the engine have a blockage somewhere? But this would probably show high temps even w/ the thermo removed. Bah. this f'ing car

Thanks!

[klits562]

How long does it take for the car to over heat at idle? If it doesnt take very long and your sure the thermo works properly its probably an air buble stick right behind the thermo, which will cause it to never open.
Another thing make sure the little dimple thing on the thermo is pointing striaght up/12 o clock

[Pirate_Freder]

well the thermostat is opening though because when he bled it water came out of the bleeder and rad filler which are both post-thermostat. what ratio of anti-freeze to water are you running?

[klits562]

well the thermostat is opening though because when he bled it water came out of the bleeder and rad filler which are both post-thermostat. what ratio of anti-freeze to water are you running?

woops true that!

How does the radiator look are the fins in good shape? Is there alot of crud caked on it or anything?

There could be blockage somewere in the system. You said the coolant splashed around in the filler neck? It should just flow smoothly right through, or am i just over thinking?

[homeslicej2]

Did you remember to slide the HVAC control all the way to full hot while you were bleeding the system?

[jt1583]

thanks for the suggestions guys, I tried them all at one point or another and I just got done driving the car about 30 minutes on the highway home, after what I think to be a successful bleeding. The two things I did different were

kept bleed screw off until coolant flowed constantly out of the hole, then capping it. Obviously don't let this occur for too long, but make sure it's complete liquid coming out.

used a funnel with a neck slightly smaller than radiator fill tube, so it could firmly sit in there, and I could keep a bit of coolant in there while the car was running. I think this helped to prevent air from coming back in, which isn't a big issue imo, but it's also easy to see bubbles escaping, which feels good :biggrin:

the car runs at a steady 180*F during anything above idle, but unfortunately I see 195*F at idle if I let the car sit for about 2 minutes. If I rev the car at 2k rpm while sitting still, the temperature quickly falls back to 180*F. is this normal?

PS - the radiator is a koyo, about 2 years old, except the fins on the inside look brownish. I don't think I have oil in the coolant, it looks crystal green when it comes out and my oil looks great too. The system can cool itself fine at 2k rpm or over, but at idle rpm it seems I can't get enough coolant through the system.

[Pirate_Freder]

interesting, as I asked earlier though, what is your anti-freeze/coolant ratio? also what kind of fan(s) are you running? how old is your water pump/what brand? is your pump pulley stock?

[dawagarage]

thermostat installed correctly? (spring facing inwards of the engine) & jiggle valve facing up?

[GeneStarWindGSW]

i know some people cut the jiggle valve off as it allows coolant to pass and if there is any air behind the thermo it can get through. Also check your belt tension on the WP to make sure its not too loose or too tight.

[Neon_rain519]

while you were filling the coolant was your heater on hot and blower on high?( sorry if i missed that) and I had to bleed mine about 6 times before it stopped over heating

[JKL1031]

I just tried to bleed mines. I thought i had it but in diff. traffic conditions, it overheatd.

Im thinkin about putting something disolvable like an aspirin pill in the Tstat to keep it open, and then installing it and bleeding??

[jt1583]

mine is still being a little bitch too. I heard about the aspirin trick as well, so the aluminum head doesn't get any aches. ahahah im so lame.

Anyways, I'm seeing temps climb to 210*F at low speeds/idle, but cruising is steady around 180*F. I've done some research and people say 210 is ok (apparently AC fan comes on around this?), but I don't like it, especially since I have 180*F at cruising. A 30* fluctuation seems like way too much to me.

I'm going to flush it, test the thermo, remove the jiggle valve and maybe drill that hole out just a little larger and then reinstall/bleed. I will also install my old skidplate once I receive my rivet gun to repair it.

I'll let any poor saps who are forced to read this thread to save their cars know how I make out.

[JKL1031]

On my second attempt, far as I could get was the temp would climb, turn the hearter on, give it gas, the temp would go down, All while in park.

I wud drill holes or stick it open with an aspirin if it was all up to me, but we decided to let a shop handle it. Ive arose to several possibilities, but my bottom hose is still cold, so theres still no flow. could be the water pump.

[JKL1031]

it was several holes someone drilled if i remember correctly.

[ca18det240sx]

i didnt read what the other guys wrote,but when you filled up the rad,you have to open the bleeder valve should be by the valve cover,open that up,then rev it till you see coolant come out,and if it still over heats,make sure your water pump is good,and your fins are clear.

[nismoman]

Ok let's rewind back to the beginning here. If there was no thermostat in the car before this means the previous owner had an issue and removed it as a dumb way to fix it. Bleeding the cooling system isn't this hard I've done it so many times. You need to figure out why the thermostat was removed to begin with. Is your water pump good? Do you have electric fans? Are they working?
To fill and bleed the system open the rad cap and bleed valve fill the rad until water comes out the bleed hole with no bubbles. Close bleed hole. Top off rad, squeeze the hoses to remove bubbles. Start car with cap off letting it warm up and rev to 2000 3000 rpms a few times to circulate coolant. Getting the engine fully warm opens the thermostat. Keep filling the rad if it needs it. Turn off car put cap on, fill resevior.

[jt1583]

So you keep the rad cap off the entire time? I have a funnel that fits great in the rad filler neck so this is possible for me, and I just keep that full of coolant so I can see bubbles coming out.

I am going to give it another shot during christmas break, I will take all components off, flush it and try this again. I may even disconnect the heater when filling as the FSM recommends. Along w/ a hole or 2 in the thermo.

It is drivable now, however. At idle and cruising it sits around 180*F but when leaving a stoplight, after about 1/4 mile my temp sensor will get to 200*F then come quickly back down. I don't think a fluctuation this high is normal. Thanks for the help guys.

[jt1583]

just how hot/warm should my lower radiator house be getting? I just parked the car after it reached 210°F and my lower hose was quite cool. I wonder if this is because a good cooling in the radiator or poor opening off the thermostat. I tested it before installing and it did open in got water but I'm about to go ahead and take this dumb thing back out.

[Garber]

just how hot/warm should my lower radiator house be getting? I just parked the car after it reached 210°F and my lower hose was quite cool. I wonder if this is because a good cooling in the radiator or poor opening off the thermostat. I tested it before installing and it did open in got water but I'm about to go ahead and take this dumb thing back out.

if your radiator is really good it will be cool.


you said the temp dropped at idle after revving it.... sounds like your water pump isnt working very well... the extra rpms allowed the fluid to circulate faster cooling it down more.

[jt1583]

That was the case but now the behavior has changed a good bit. Unless I idle for a long long time, the temperature is ok, around 180 like cruising. Briefly after getting moving from idle the temperature climbs up to sometimes 210 then settles back to 180. I don't think this is healthy.

I found a picture of water pump during ht install process and it looks great. I have 2 electric altima fans mounted right against the radiator that are pulling, the bottom of the radiator, the air passing thru (behind the fans) and the lower hose are all quite cool. I would think these would get hot if there's not flow? This thing is driving me crazy why can't car issues ever be as simple as they should be.

Does anyone think this could be because my plastic skidplate is still off?

[JKL1031]

if your radiator is really good it will be cool.


you said the temp dropped at idle after revving it.... sounds like your water pump isnt working very well... the extra rpms allowed the fluid to circulate faster cooling it down more.

Thats what Ihad going on, along with a cool bottom hose.

[JKL1031]

cool bottom hose means their is no circulationg. the coolant is basicly just sitting around I guess??

We may be having the same problem, but ive never kept it in over a day.

Should i also fill the upper hose up and get some coolant to reach the back of the tstat rather than just filling up the rad? Dont think It will be me, but a professional trying this next time.

[jt1583]

I read a tip from some guy to disconnect the upper hose from the rad and fill it from there. Top down fill approach seems logical.

I do however disagree with the cool bottom hose = no flow. If this isn't flowing the top hose shouldn't be flowing either, and my temp sensor would be reading a lot hotter and not come down. It seriously goes from 180 - 210 in 3 seconds sometimes and back down just as fast too. Sounds like a bad thermo to me. I will probably get another and drill it. This thing sucks balls.

So your mechanic hasn't touched/fixed it yet? If he does please try and ask him what the fix was. Sometimes they will deflect the question but be persistent!

[Garber]

yeah try a new thermo and test it before you put it on. drill a small hole in it to let air pass through it. mount it with the hole on the upper side (air floats lol).



out of curiosity, its not building lots of pressure in the coolant system quickly is it? do your hoses feel really pressurized after running the car for only a minute or too? is it losing any coolant? when coolant was "splashing out" was it smoothly overflowing or was it bubbling out?

[Garber]

I do however disagree with the cool bottom hose = no flow. If this isn't flowing the top hose shouldn't be flowing either, and my temp sensor would be reading a lot hotter and not come down.

the top hose may still feel warm because there is nothing blocking the hot water from around the engine from mixing with the cool water in the radiator hose. the turbulance cause by the waterpumps bypass circulation and vibration of the motor will mix it.

take the rad cap off, start your car when its cold, stick your finger in the top and wait. you will feel the water slowly get warmer from what i jsut talked about before the thermo even opens.

OP, ignore this last paragraph, this is obviously not relevant to your situation, just for reference and discussion :)

[JKL1031]

No I hadnt taken it in yet. like i said, mines will heat up and go down after revving it as well. My bottom hose would be cold.

I should have tried filling it top down like i guessd, but i was running out of time. If i fill it thru the rad, and the thermo is closed, the water just sits there on the front of the tstat, and stay cool. If i fill from the back, the water will get hot, touching the back of it where the temp senser is, and should open it up. Now does the temp sensing element repsond to the engine temp,(could you put it in a hot room, and it still open.), or the temp of the water touching it?

I did manage to get a stream of coolant to come out of the bleeder sccrew once before so there probly is some circulation. Could my pump be too weak to push through the tstat, and keeping the water from moving fast enough?

[imcunner]

Could it be that the coolant temp sensor is jacked up?

[JKL1031]

nah it seems fair. I believe its my pump. Ive had it over heat with no pressure on the lowerhose, and when i rev the engine along with turning on the heater, it drops.

How hard/expensive is the labor for the pump?

[nismoman]

Pump is like 30 bucks easy to install yourself. Pick up the $2 gasket also

[GeneStarWindGSW]

without proper bleeding, car will overheat quick. just jack it up (doesnt even need to be too high), take off the screw by coolant sensors, put in fluid (squeeze top hose to get air out faster) and once you see a nice stream of coolant coming out of the top screw hole.. screw it back in and top off the rad. your done. id replace both sensors for piece of mind with the pump & thermo while ur at it. [if they haven't been replaced already]

also double check all your coolant hoses are good (not brittle, cracked, clogged up or leaking...my lower radiator hose had a pin size hole in it. It leaked little by little and i didn't notice it. It got my car to start heating up till and i had to park my car in some parking lot and fix it right then and there)

[dawagarage]

maaan, fuuuuck the KA and its notoriety for trapping air. have you heard of a swirl pot? it completely negates burping, it removes the trapped air for you. i got tired of the manual/regular and finally forked over 80 bucks (60 for swirl pot, 20 for lower rad hose connection.) i highly suggest everyone do the same, its well worth it.
a photo of how it works.
http://www.gtfactory.jp/cms/e107_files/public/1221255814_2_FT2942_breatherdsm.jpg
and where you can get it. POWERED BY MAX: (http://www.gtfactory.jp/cms/page.php?11)
other companies make them too! idk about the prices or what other companies provide them.

[JKL1031]

Just wondering, in the meantime, should or could I block off my top hose for more heat? Would putting cardboard infront of the rad as well be worth anything?

[jt1583]

I don't think cardboard in front of the radiator is a good idea.

I consider my problem fixed, I re-bled the system once or twice and now the temperature bounces from 180-185, so I'm happy.

I verified there was indeed air in the system by first removing the bleed screw and squeezing the lower tube. I could squeeze it a good bit before any liquid came out of the hole. So I reinstalled the bleeder screw, removed rad cap, inserted fill funnel into the neck and put a bit of fluid in there. Then I removed the bleeder screw until fluid came out and reinstalled it. Ran the engine til warm with the funnel still in place while squeezing the upper and lower hoses, revving the engine, and bouncing on the car, left and right.

[JKL1031]

well ive done it for some days just for more heat. does fine in 38F+ Im putting it in the shop monday.

[JKL1031]

I got it back from a professional and now it slightly begeins to overheat. the the tstat seems to open up and i felt the bottom hose get hot once. and now its back cool.

Does the sttat only open when its hot or is it supposed to stay open or slightly open at all times?

[nismoman]

what makes you think its slightly overheating? i mean are you going by the stock gauge or what? The thermostat is closed except for the weep hole until it gets really close to the open temp then it should open relatively fast.

[JKL1031]

By slightly; when i was out, it was creeping up and down depending on engine speed and car speed, but still in acceptable levels. It finally went super high and boiled to the overflow. Its a slow speed problem fan or radiator. Back to the shop monday.

[JKL1031]

-facepalm circulation problem*

[bradg1313]

I noticed you said you had a swap, I have heard of the sensors from a 89-94, not working (making it read hot)for a 95-98... making it do the very same thing as you describe. Make sure you have the right sensors for the right year ka... Just throwin it out there

[JKL1031]

anyone ever ran their tstat mechanically stuck open?

[JKL1031]

..

own thread

[SpaceGuy85]

Hi guys, I believe this to be an issue with bleeding the system and while I have looked through a bunch of threads about bleeding/overheating, the bleed procedure is still unclear to me.

Setup - Stock KA24DE, koyo radiator, Defi coolant temp gauge w/ sender in upper radiator hose. Boiling-water method tested thermostat, recently filled the system with ~1.5 gallons coolant.

Quick background - I swapped in a used KA24DE recently and am just trying to get this damn thing running like stock. After installing it ran good, no leaks of any sort, except it would rarely get up to temperature. 140F was normal, maybe around 170 in traffic. So I got an OEM thermo and went to replace it and found nothing to replace, so I installed it. Some idiot was running this thing thermoless. After installing and filling w/ coolant, I used the bleed procedure outlined below. However I can't drive the car more than 2 miles if it's been warmed up without my Defi reading 200+. NOT GOOD!

Ok so to bleed here is what I did
-Jack front of vehicle up a good bit
-Undo bleed screw, and rad cap. Fill system til the radiator is full - nothing came out of the bleeder hole
-Then I ran the car, after about 5 minutes I saw coolant starting to splash out of the bleeder so I closed that. A few minutes later the radiator filler started splashing pretty aggressively, so I closed that.
-After this I tried to let it run but it climbed too hot and I shut it down.
-I allowed the car to cool and tried to fill it up but the system didn't want to take much more. The reservoir become emptied once but then I filled it and it was full for good.

Am I doing something very wrong here? My CA18 was easy as pie to bleed. I have heard about squeezing the lower rad hose during this whole bleeding process and will try it. I get another opportunity tomorrow to work on the car, so any advice is appreciated.

BTW, I read in another thread that if the thermo works it can only be air bubbles causing something like this, but what about blockages? What I am afraid of is the the previous engine owner removed the thermostat because of another more serious, underlying issue and I don't want to have this be the case, obviously. When I think about the coolant system, if the pump works, and the thermo works, and the radiator isn't blocked, what can go wrong? Can the engine have a blockage somewhere? But this would probably show high temps even w/ the thermo removed. Bah. this f'ing car

Thanks!

You problem is that you installed the new theremo in the wrong place. It is not the top posistion. the one on the front of the engine, next to the water pump is where the thermostat goes. If you put one in the location you listed, it will cause overheating.

SpaceGuy 85
2003 Nissan Frontier 2.4L