Coolent Temp going mad

[Ayeobe]

Okay, so im pretty sure its a lose connection, but lets think worse case scenario here.. My coolant temp guage has been freaking out all day. It would go all the way up to past the red H line and then go back down to normal operating temp. A friend of mine figures its just a loose connection, but i'd like more than one opinion. Also, i did the search and couldnt find anything directly related to this problem.

Im pulling up the shop manual to check things out on my end aswell.

[1989accordaz]

Mine did that long time ago, and I remember running the heater on high to try to dissipate the heat and help it cool down, and at times it would not blow hot air, just ambient type of temperature, then after a few seconds back to blowing hot air again.

During this time, the temp gauge would go from normal to almost red line.

So hot coolant was not passing through the heater core. What ended up being was just air and low coolant in the system.

But of course, you probably ruled this out.

[Ayeobe]

Nah, the air is hot. It blows hot as soon as the engine heats up, and stays hot. Im gona check the coolant level, but its not the easyest to check on these cars lol. Im not worse off tho, cause my batt is small, so i get a decent view of the coolant reservoir. I havnt ruled much out, cause i havnt had a look at it. Its pooring out.

When i unplugged the sensor, the CEL came on, and the idle went up. When i plugged it back in, i turned the car off and on again and the temp was at normal for a bit, but then went back way up.. When i got back from work it was fine, and when i hit a massive bump it went way up again, then came back down after a few bumps..

[w261w261]

Make the coolant easier to check:
--------------------------------

A. Clean out the bottle: Remove battery, tray, and bottle. clean with an anti-rust solution like "Must for Rust."

B. Use a dark anti-freeze like Peak.

C. Use a flashlight. Bump down the front of the car to get the fluid to move a bit and you can check the level fine.

D. Get used to doing this so you don't overheat and cause real damage. My experience on this board is there's way too many people that shut their eyes and try to ignore the possible low coolant.

Make sure you don't have an air bubble in the system:
---------------------------------------------------

Bleed using the valve (bolt) by the thermostat. See the many threads on here on how to do it. An air bubble passing a sensor can erroneously indicate a high temperature.

[InAccordance]

mine does this and has since i got it
I can smack the cluster and it drops back down to normal.
car has never overheated and coolant is topped at all times
A- sending unti is bad
B- bad connection somewhere between the cluster and sensor
C- gauge is fuxxored

[Ayeobe]

Okay, so i read a bit and to bleed the system i have to i guess make sure its full, then fill it slowly while the little valve is open? Does that include running the engine?

[carotman]

When i unplugged the sensor, the CEL came on, and the idle went up. When i plugged it back in, i turned the car off and on again and the temp was at normal for a bit, but then went back way up.. When i got back from work it was fine, and when i hit a massive bump it went way up again, then came back down after a few bumps..

You unplugged the sensor for the ECU, not for the gauge cluster.

The one for the gauges is the 1 wire sensor.

[Dr_Snooz]

^^ 2nd that. The gauge wire won't turn on any CELs. When you find it, you probably notice that the connector on it is hosed though.

[Ayeobe]

K perfect, so im still getting the problem after doing the coolant flush, so its gotta be electrical right? Is the sensor for the gauge around the same place as the one for the ECU?I gotta get this fixed before my friend bands me from usin my car for roadtrips we do lol

Also, how does it work? Is it more heat = more resistance, or more heat = less resistance?

[AccordEpicenter]

if its a loose or intermittant connection the temp gauge will fall to cold not hot, i think you have an overheating problem

[2drSE-i]

When you bleed your coolant, be sure that when you shut the bleed valve it is a constant flow of coolant, no bubbles. If that's not it, maybe time for a new thermostat.

[w261w261]

When you bleed your coolant, be sure that when you shut the bleed valve it is a constant flow of coolant, no bubbles. If that's not it, maybe time for a new thermostat.

I'll second that. You have to bleed it for longer than you think, a good while. You also don't have to open the bleed screw wide open either. Just enough to keep liquid coming out. Before going further, I'd bleed it again, as what you are describing sounds just like air bubbles

[Oldblueaccord]

Actually in the manual it tells you to open the bleed bolt then add coolant to the neck of the radiator. not running.

I do do it running and bleed it just like you would brakes so I close the bolt when I see a steady stream. I do also rev the motor a little so there's a nice flow of coolant as well.

DOesnt hurt to run the car with the cap off for 10 mins and remember to run the heater on open to let flow thru there.


wp

EDIT I am digging for the resistance spec in the Helms but I cant find it. There calling it a "thermo unit".

p. 25-111 1988 Helms 133F is 142 ohms 185F is 32 ohms 212f is 49 ohms

[w261w261]

I guess I should mention also that the coolant has to be brought up to temperature enough to open the thermostat.

1. With a cool or almost engine, open the radiator cap CAREFULLY and add enough coolant to bring it up to the top. In the overflow bottle, add enough coolant to bring it about halfway between the low mark and the high mark. At this point, if there has been a drop in fluid, ponder what it means.

2. Open the heater valve by moving the heat lever to the hot position.

3. Leaving the radiator cap off, start the engine and let it run until the thermostat opens. You can tell that this has happened by looking down at the fluid in the radiator and see it flowing.

4. Open the bleed valve slowly, but not too far, just enough to get the fluid to start coming out. It will probably start spitting intermittently. Let it do this for awhile, because the air bubbles have to travel from the far points of the system. Add coolant to the radiator as or if it drops.

5. When after a few minutes the stream is constant from the bleed valve, close the valve (don't put a gorilla move on it, it isn't that big a thread).

6. If you haven't bought a new radiator cap in a couple of years, now's the time to do it. A cap is actually a pressure relief valve, and as such has a moving part inside. It's vital to the correct functioning of the system.

[Dr_Snooz]

Just to muddy the waters further, I have to jack up the front of my car to get it to bleed properly.

[w261w261]

Just to muddy the waters further, I have to jack up the front of my car to get it to bleed properly.

When be the last time you flushed your cooling system?

[Dr_Snooz]

It was somewhere around March of this year. I used the Evan's lifetime coolant and it's a little thicker than regular coolant. My cooling system is pretty much all new because the old one disintegrated on me. I still had trouble getting it bled properly with the regular coolant.

Evan's thread:
https://www.3geez.com/forum/showthrea...ight=evans+npg

[w261w261]

I have this mental image of the air bubbles moving s-l-o-w-l-y up through the sludge-like coolant. BUUUUUURRRRRPPP! And just how did you get all the water mixture out of the system before adding the new stuff? Even with the block drain, I would think that it would be difficult.

[Dr_Snooz]

I haven't managed to find a block drain on this car. I just did the best I could, then ran it with Sierra coolant for a few days. I have to get the car hot before I bleed it.

[w261w261]

Several years ago when I last flushed my system, I didn't find the block drain either, but I also didn't look very hard. I did measure the amount of coolant that I got out of the radiator drain, and compared it to the stated coolant capacity from the manual. It was about 40 or 45% as I recall. I therefore filled up the radiator with antifreeze/distilled water a couple of times, let the thermostat open for awhile, then drained out the mixture and repeated. Environmentally, it sucked I guess, but I ended up with a nice mixture of coolant/distilled water that only this year showed some signs of rust. First nice day this fall I'll repeat the process.

Since you didn't do that, I'm thinking you have a significant amount of water still in the system.

[Ayeobe]

Well this is all duely noted, and i will do it tomorow. One thing, actually, that i just noticed. the car dosnt do anything funny at night, when the weather is closer to freezing. In the day. though, the right front signal light shows off its bad-contact, and the coolant temp gauge goes crazy. At night, though, i let the car idle untill it at least steadys out to 1100rpm before leaving, so i have plenty of time to see the temp gauge go to NOT. In the day, it also seems to ither sit above or below what i beleive NOT is on the gauge.. so, im figureing something more of an electrical bug, ne? I'll make sure the garage did its job, though, and take shit apart tomorow, before i wash it.

[K3VL4R]

I'm having problems with my 89 accord lx-i automatic.
the temp jumps almost to the red high mark after only having driven 4 or 5 miles, maybe less... I have to manage the heat with the internal heat/defrost controls.

Any help or suggestions?

thanks for looking

K3VL4R

[w261w261]

I'm having problems with my 89 accord lx-i automatic.
the temp jumps almost to the red high mark after only having driven 4 or 5 miles, maybe less... I have to manage the heat with the internal heat/defrost controls.

Any help or suggestions?

thanks for looking

K3VL4R

Look up at the top of the page, find the "search" button and go from there.

[JDMPrelude23]

Make the coolant easier to check:
--------------------------------

A. Clean out the bottle: Remove battery, tray, and bottle. clean with an anti-rust solution like "Must for Rust."

B. Use a dark anti-freeze like Peak.

C. Use a flashlight. Bump down the front of the car to get the fluid to move a bit and you can check the level fine.

D. Get used to doing this so you don't overheat and cause real damage. My experience on this board is there's way too many people that shut their eyes and try to ignore the possible low coolant.

Make sure you don't have an air bubble in the system:
---------------------------------------------------

Bleed using the valve (bolt) by the thermostat. See the many threads on here on how to do it. An air bubble passing a sensor can erroneously indicate a high temperature.

Nice! ima try this asap

[JDMPrelude23]

I guess I should mention also that the coolant has to be brought up to temperature enough to open the thermostat.

1. With a cool or almost engine, open the radiator cap CAREFULLY and add enough coolant to bring it up to the top. In the overflow bottle, add enough coolant to bring it about halfway between the low mark and the high mark. At this point, if there has been a drop in fluid, ponder what it means.

2. Open the heater valve by moving the heat lever to the hot position.

3. Leaving the radiator cap off, start the engine and let it run until the thermostat opens. You can tell that this has happened by looking down at the fluid in the radiator and see it flowing.

4. Open the bleed valve slowly, but not too far, just enough to get the fluid to start coming out. It will probably start spitting intermittently. Let it do this for awhile, because the air bubbles have to travel from the far points of the system. Add coolant to the radiator as or if it drops.

5. When after a few minutes the stream is constant from the bleed valve, close the valve (don't put a gorilla move on it, it isn't that big a thread).

6. If you haven't bought a new radiator cap in a couple of years, now's the time to do it. A cap is actually a pressure relief valve, and as such has a moving part inside. It's vital to the correct functioning of the system.

WOW! i kno i aint write this thread but thanks lol.... gonna do this as soon as i get home