B16 fiat x19 2 steps forward, 1.5 steps back. Coolant issue

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autox19

Member
so here is the issue, then I will explain. I dont think I am getting any circulation. I know I am not getting enough to push the coolant through the radiator as the hoses are cold and I shut off the engine at 200.

Info needed for diagnoses;
  • radiator is not plugged, that validated with a squeeze one hose and coolant comes out the other
  • new thermostat
  • Old water pump (with swapping from one engine to the other I forgot to swap the new pump over. ugh)
  • no leaks or noise coming from old pump
  • radiator is bled with coolant coming out the bleeder at the top
  • bleeder on head has coolant running out with engine on or off. while loose. no leaks when tight
Diagram of how I have things routed.

coolant.JPG


Other than that, now that I have the timing right, it starts right up and purrs like a kitten!
the .5 step back is I didnt program the tunerview II correctly and have peak values for ECT rather than live. easy fix, but was annoying to have to go off the page then back on to see the temp

Odie
 
hmm
the diagram looks correct

my first thought is that with the radiator up front and the thermostat in the rear the coolant might be loosing too much temp on the way back to the engine to open the thermostat

?????????

here are the test specs for an OEM Honda thermostat
2jio9l.png
 
hoses are correct, hot on top, cool on bottom.

Interesting thought. on the thermostat not opening. I dont remember checking to see if the housing was getting warm. Educate me. if the stat is closed, that would cause there to be no circulation and only if the heat traversed the entire path form the engine to the radiator back to the stat. is it possible that the small hole in the stat isnt allowing enough coolant through to have any circulation? I did notice the stat I took out had the small hole at the top where there was a relief spot, where as the replacement was more in the middle. Havent tested the stat yet

Odie
 
another thought. because the bypass is going to my heater, if the heater is either off or blocked, then the bypass will never run coolant past the thermostat. correct? should I hook up a loop for the bypass just to check?

Odie
 
Is the top hose on radiator above or below in comparison to where it connects on motor? I'm wondering if there is air in the system. If thermo isn't opening.....no way you can circulate and get all air out.

You can test thermo in a cup of hot water and see if it opens.
 
top is below the stock honda bleeder. there is a bleeder on the top of the radiator that I kept open when filling until it spilled out. I have someone on another page saying I have the flow backwards. seeing how the water pump looks, I dont think they are right, can someone confirm if i have the flow direction right? if I am backward, then i most likely have to swap the coolant hoses to the radiator around

Odie
 
I almost guarantee you have a heater hose crossed on the thermostat housing mixed with the one that goes on the intake manifold, I do it literally on accident almost every time I remove a head off a honda then go wtf why do I have no heat , esp if the car is running fine and fine temps
 
I have high temps. 200. that is when I started to suspect no circulation. I thought about having those reversed as well, then I realized that I have the thermostat housing that the 2 are 1/2 inch apart. not the type that has the return halfway down the pipe. that should be close enough to open the thermostat.

and I just posted that exact same pic on the fiat forum also explaining that the intake of a water pump is in the center, where that pipe goes to.
I am not going to be home for a few days, but what do you guys think of this plan of attack:
step 1. test thermostat, even if new, they sometimes are bad.
step 2. check for flow at the bypass hose. it will be messy, but will tell me if the water pump is working.
step 3. cry
step 4. pull engine again, and see what i can see.
step somewhere in the middle. do some kind of power flush?

Odie
 
my problem has always been with a hose crossed as mentioned (d/b series) its 2 pressure lines soo no flow, one is suction on the coolant tube leading to the thermostat on the back of the block and one is post thermostat on the housing which are the ones I have crossed multiple times, obviously the other line is on the side of the head
 
step 1. open up all of the hoods and stare at it for a little while
step 2. profanity
step 3. have a beverage of some sort (preferably between 5.5-60% ABV)
step 4. more profanity
step 5. have a friend come over to stare at it with you
step 6. have another beverage, offer friend a beverage
step 7. more profanity at a higher volume
step 8. poke at it with a stick (or some other object)
step 9. maybe another beverage
step 10. cry a bit
step 11. get called a fag by your friend for crying
step 12. argue a bit
step 13. hug it out
step 14. have another beverage
step 15. poke at it with a stick some more
step 16. a little more profanity
step 17. stare at it with a bewildered look
step 18. give up and go grill some burgers or something


somewhere in these steps you should reach the hidden step of **EPIPHANY**
 
i think i understand. I am not at home for a few days so I cant check. but i will check when i get back. I am 92% sure I have it like this. big hose on transmission side of thermostat goes to bottom of radiator. Big hose on side of head is the return from the radiator. this hose has a tee for the expansion tank. on the other side of the thermostat there are 2 nipples (yes I always giggle at typing nipples) the closest to the thermostat is the return from the heater core (currently closed) and returns to the side of the head. the next nipple is the bypass that goes directly to the intake manifold.

odie
 
Thermo should open and that's when the fluid in the radiator goes from the bottom hose to the thermostat. Thats when more coolant needs to be added. You're saying the top radiator inlet is lower than where it comes out near head/tIming belt side. So, a few thermostat opening cycles (fluid being added as needed) and you're good to go (in terms of bleeding the system).
 
talked to some friends about this tonight
they seem to think you might be air locked

the suggestion was to put the front of the car as high in the air as you can to get the radiator opening as high above the engine as possible
then run the car to get the air out of the lines (the radiator is up front right?)

another friend recommended to ease the process and minimize the mess... take a large funnel and cut most of the nozzle off then use tape to seal it to the opening in the radiator, this will allow the fluid level to go up and down without spilling shit all over the floor
keep fluid in the funnel... the level should go up and down while everything circulates and the air is burped from the system
when the engine is at temp and the level stabilizes you should have all of the air out
cap it and lower the nose

another idea was to completely remove the thermostat
if it is still overheating it is definitely not an issue with the thermostat not opening and points more toward the air lock situation
 
First idea is possible. Second not so much. The vent on the radiator is a 8mm allen bolt that is about 3 inches long so I can be accessed from the front trunk. I real pain to get to.

The fiat side agrees that it is air locked. Here is thier suggestion. They are thinking my expansion tank is wrong. I now think they are right. They want me to move it to the bypass circuit or heater circuit. From engine/heater to top of tank. Then bottom of tank back to the rear of thermostat. It should be always purging that way. I will also be able to see flow. Then if there is flow, test thermostat. If thermostat is good then it must be something in the radiator circuit.

Thanks you guys! You are really helping out a ton!

Odie
 
Update: routed the heater circuit to the expansion tank. No flow. Ugh. Thought about it and we took the return line off and pressurized the tank. Held 20 psi. Yeah. Double checked the heaterms valve and it was open meaning it is plugget up good. Bypassed the heater and looped it from the head to the expansion tank then expansion to the return. Success! There is flow! Now for the 1.5 steps back. After the antifreeze warmed up the thermostat opened. I could tell because when I squeezed the main hose next to the thermostat it was hot and it wasn't before. But...... it was not circulating in the main circuit. I opened the bleeder in the radiator and cold coolant dripped out. Not plugged as we can see fluid movement when we squeeze either hose.
That was it for the night. We are convinced it is air in that circuit too but not sure how to get it out. Or it could be a weak water pump, but I have never heard of that.

Odie
 
I still honestly feel like you have something crossed at the connecting pipe and thermostat body making flow not happen like I said been there done that, and the water pump either works or pisses coolant out 99.999% of the time its pretty failsafe
 
When I get a chance, I will video the routing of what I have. Might not be until next week though.

Odie
 
ok. made a quick run during lunch. i showed what i am doing for the fiat site and it shows what i did, even though it is on my other engine.



odie
 
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