Ive got a hell of an overheating problem. Ive literally done everything possible to remedy it. Ive got a JDM b16- i drained the coolant to replace an ECT sensor, because im getting starting trouble. after replacing the sensor, I filled the car up with coolant, loosened the bleed valve until it dribbled out, and tightened it down. it ened up breaking off a piece of the outlet housing. I tried to use some epoxy putty to glue the piece back together. I put it back on, turned the car over, and it started overheating. I then saw coolant dribbling out of the epoxied piece. i have since flushed the system twice, replaced the radiator, pulled out and physically inspected the water pump (in addition to holding a rad. hose while somebody turned the car over, and seeing coolant spill out of it), tapped a new hole in the coolant outlet housing and putting in a new bleed screw. Ive also installed a new thermostat, and tried a ECT sensor (to the gauge) from my D16 motor. So, my questions: What hypothesises do you guys have as to the problem? Which ECT sensor is appropriate for a JDM B16?

 

So how soon is it overheating? 10 minutes? 20 minutes?
Have you replaced the thermostat? Is the thermostat opening?
Is your fan kicking on? Is your fan switch still connected? have you tested your fan switch?

 

How do you inspect the water pump bearing ?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NikoZai &raquo;</TD></TR><TR><TD CLASS="quote">So how soon is it overheating? 10 minutes? 20 minutes?
Have you replaced the thermostat? Is the thermostat opening?
Is your fan kicking on? Is your fan switch still connected? have you tested your fan switch?

</TD></TR></TABLE>

Saved me some typing

 

if everything is working like is should and it still over heats, it could be a very small blockage in the radiator, or a large *** air bubble. had an over heating problem in iraq with a hummer.. thought it was the water pump, tuned out to be a very large air bubble.. aslo are both hoses nice and full of fluid pressure when the car is running, or not? this would let you know about the air.

 

I know you said experts only, but the same thing was happening on a Supra my boy had, did every thing that you did, turned out it was the head gasket, just another thing to keep in mind.

 

Replace the peice you broke if there is an air leak in it it can cause you to overheat...make sure the fan works...headgasket could be on the list too do a compression test...trace the coolant system for leaks...a hanging up clutch could also cause overheating...there is a lot of things it could be start with the cooling system and go from there...make sure you bleed all the air out it can get trapped behind the thermostat...I ususally run the car with the rad cap off untill it heats all the way up and add coolant as needed it takes a while but I think its the ebst way to get all the air out

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91SOHCZCCivic &raquo;</TD></TR><TR><TD CLASS="quote">I know you said experts only, but the same thing was happening on a Supra my boy had, did every thing that you did, turned out it was the head gasket, just another thing to keep in mind.</TD></TR></TABLE>

You have done every thing, this is what remains,

Do a compression check,

 

sorry about the tardy response guys; ive been real busy lately. in response to all the comments: I pulled my head off, and am in the process of throwing on a new head gasket, Ive bled the system, and burbed it, and I have my fan wired to be constantly on. The gauge reads operating temperature after running the car for only about 45 sec to 1 min. it overheats in under 5 minutes: Surprisingly quickly. Last time it overheated, the upper radiator hose didn't get hot at all. I thought there was a blockage in my head, but I after taking it off, and poking stuff in the water holes, it appers to be flowing fine (additionally, i ran some water through the outlet housing and it came out the bottom, so that reinforced the fact that it was flowing). Any other thoughts?

 

ok things to check for.

Is the lower rad hose versus top rad hose same temp? If lower rad hose cold top is hot water pump either not flowing or thermostat not opening. To check thermostat put in a pan of water and heat until see movement on the thermostat. Is the head hot and engine block cold. Might have a block in engine block versus the head.

 

good call on checking the block and head- i didnt think about that. last time the car ran, both rad hoses were the same temp- they were both cold. but my heater hose was suber hot, so i know my car was still running to hot. when i get my head back on, ill contrast the temp of the block vs the head

 

Okay, I'm not trying to insult your intelligence here, but are you just using straight coolant or is it a mix with water? From my own experience, it needs water

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rbwdriven &raquo;</TD></TR><TR><TD CLASS="quote">ok things to check for.

Is the lower rad hose versus top rad hose same temp? If lower rad hose cold top is hot water pump either not flowing or thermostat not opening. To check thermostat put in a pan of water and heat until see movement on the thermostat. Is the head hot and engine block cold. Might have a block in engine block versus the head.</TD></TR></TABLE>

this makes no sense to me^. lower rad hose should be cooler then the top since the cooler coolant comes out the bottom. but it shouldnt be cold. the top should be hot since thats what lets hot coolant into the rad. if you open your rad cap then start the car and wait for it to warm up and you see the coolant moving then im sure your pump is fine. sounds like air lock to me.. im not an expert.. but i am learning this in college at the moment if that helps lol.. sounds like you need all the help you can get though..

 

-While the radiator has no coolant throw some air (compressed air, or blow on the top radiator hole and feel for air coming out the bottom hole) through the radiator make sure its flowing all the way through ( i know its new, trust me, do this) after that..

-When you get that head gasket on make sure you bleed the system correctly, thus letting the engine run with the cap off until radiator fan comes on...making sure both top and bottom hoses are the same temp...

 

i went through somewhat of the same bullshit for 3 weeks bro so listen here.

i ended up running straight water in my system for 6 months, heres what hapened:

the fins on the water pump got little dimples of rust on them, and i believe this was causing cavitation of the water pump at higher RPM/temperature.

i replaced it all and finally i replaced my water pump and it solved the problem.

moral of the story, always run a little bit of antifreeze in the rad to keep that **** from rusting.

 

you should always run antifreeze in the coolant.. it raises the boiling point of the coolant. along with lowering the freezing point.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by janz3n &raquo;</TD></TR><TR><TD CLASS="quote">you should always run antifreeze in the coolant.. it raises the boiling point of the coolant. along with lowering the freezing point.</TD></TR></TABLE>

still decreases cooling capacity. distilled water works great for hot summers.

 

I was running a prestone 50/50 mix.... After I had bled and flushed the system for probably the 5th time, I ended up putting the 50/50 back in, minus a little bit that I lost just from being clumsy. Since I didn't have any more, I put in a little bit of the straight coolant to top it off. Is there anyway possible way a water pump can fail, even when it passes a visual inspection? When I looked in the radiator to check coolant flow, it seemed to flow sometimes, and sometimes it wouldnt. It was very strange. In fact, I think I only saw it flowing with in the first 30 seconds of turning the car over. Hopefully Ill be able to put the head on tomorrow afternoon. If I have enough time to get it all back together, Ill let you guys know the status. Thanks for all the responses thus far

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by naptownrex &raquo;</TD></TR><TR><TD CLASS="quote">I was running a prestone 50/50 mix.... After I had bled and flushed the system for probably the 5th time, I ended up putting the 50/50 back in, minus a little bit that I lost just from being clumsy. Since I didn't have any more, I put in a little bit of the straight coolant to top it off. Is there anyway possible way a water pump can fail, even when it passes a visual inspection? When I looked in the radiator to check coolant flow, it seemed to flow sometimes, and sometimes it wouldnt. It was very strange. In fact, I think I only saw it flowing with in the first 30 seconds of turning the car over. Hopefully Ill be able to put the head on tomorrow afternoon. If I have enough time to get it all back together, Ill let you guys know the status. Thanks for all the responses thus far</TD></TR></TABLE>

Usually is the water pump is leaking from the weap hole, that's when its bad, usually.

How do you see coolant flowing from the radiator cap, I mean its just a little hole, you can't really see coolant moving around. The only time I ever see coolant move is when it bubbles, either from air or from the heat ( no pressure in the system, lower boiling points ) . I don't no, I just would not use this method to check for coolant flowing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by naptownrex &raquo;</TD></TR><TR><TD CLASS="quote">sorry about the tardy response guys; ive been real busy lately. in response to all the comments: I pulled my head off, and am in the process of throwing on a new head gasket, Ive bled the system, and burbed it, and I have my fan wired to be constantly on. The gauge reads operating temperature after running the car for only about 45 sec to 1 min. it overheats in under 5 minutes: Surprisingly quickly. Last time it overheated, the upper radiator hose didn't get hot at all. I thought there was a blockage in my head, but I after taking it off, and poking stuff in the water holes, it appers to be flowing fine (additionally, i ran some water through the outlet housing and it came out the bottom, so that reinforced the fact that it was flowing). Any other thoughts?</TD></TR></TABLE>

It still sounds like you have a thermostat problem, I have installed brand new ones before that have indeed stuck open or closed.

Also are you getting hot or cold air when the heat is on ?

 

Is the motor and coolant system showing signs of overheating or is the guage bad ! ? I had my guage go bad and the car was not exhibiting any weird behavior but the guage displayed a really high temp. Just a thought from my own experiences.

 

I had something simalar happen to me. After driving for about 30-45 seconds, the temp gauge would shoot all the way up to hot, and stay there. Then, if I shut the car off, it wouldnt start until it was cool again. It ended up being my main relay. I'm not sure if that's how it is with you, but thats what happened to me.
Good luck.

 

Im pretty sure my car is overheating- I pullled the spark plugs out and they're were white- if I remember correctly, that means the motor is running hot (or lean). Does anybody know of a way to check for proper operation of the cooloant gauge? I guess Ill check the thermostat again- Unfortunately I dont have AC or Heat any more, so I can't test either.

 

Ever check or change the thermostat? Was the new stat put in backwards? Both rad hoses being cold sounds like a stuck stat to me.

 

check the guage sending unit mine went bad and was making me think my car was over heating till i replaced it and it worked mint....

 

Have you replaced the radiator cap?

Take the thermostat completely out then run the car. If it still over heats, obviously it's not the thermostat.

How don't you have heat? Did you remove your heater core and how did you go about doing that?

And on a side note, if I were having these problems I would just be filling it with water and worry about a correct mixture later.

 

Checked and changed the thermostat, and I changed the sending unit out with my old d16a6 unit, and neither helped my problem. Thanks though guys