Engine overheating

[2Fast4U86]

So a quick question...

Engine overheats at idle, turning cabin heat to full or driving fast gets rid of it. Fans turn on, but only when the temp. gauge gets to about 80% of the way up.

I have:
Put in a brand-new dealer-bought thermostat
Re-filled the radiator with honda-brand coolant
Tried a different (only 1 - the fucker charged me $5 for it, so I couldn't get many - I was feeling honest that day) junkyard fan relay.

So what now? Is draining the bastard and trying to get to/replace the sensor on the bottom of the rad. my only possible solution?

Thanks,

2Fast4U

[njpeter]

1-bleed air from system?
2-check for good radiator water flow? ( they do get clogged yanno)
3-check water pump belt? ( obvious but often missed)
4-check oil?
5-run a/c at idle to force cooling fans on?
6-check actual water temp? ( sender failure is rare in my mind )
7-pray to the god of head gaskets? ( this can cause really strange and hard to diagnose using common sense overheating
8-find me an auto tranny?

[ACCORD EX]

what color is the coolant !

does the car run ok rather than that !

MIKE

[rocky2]

Idle engine till cooling fan comes on. If it don't feel all hoses for hotness. If ones still cool,we have a problem.

[2Fast4U86]

1-The system's been bled!
2-The 2 pipe thing? They're both hot.
3-The water pump was replaced 5 days ago, when I had my timing and other belts done.
4-Oil is good.
5-AC is dead... so the compressor probbly works, but... what do I care? The engine overheats without any help.
6-Not sure how to get a water temperature reading. Plus the temp. does come down when I turn the heater on, or the fans come on. hmm...
7-Hopefully its not the head gasket.
8-Why you want an auto tranny? I've one.

The coolant is green! It's brand new honda type 2 that I just put in! comeon now...

[Dutchboy]

was the thermostat replaced the right way in??????

if it wasnt then itll take forever for it to open since its backwards

that would make sense why the fan isnt kicking in till its so hot...the fan uses the heat of the coolant in the rad to kick in...
so if the thermostat isnt open itll read really hot on the temperature gauge and the rad could be fairly cool since the coolant isnt coming through yet.

if the fans kick in it should cool down no problem......if it doesnt hten theres something else wrong

[Neuspeed007]

CHECK FOR A LEAK! if not just get a new radiator, or get your hoses replaced. that should take care of any temp problems

[njpeter]

you take a temp reading with a meat thermometer..just to make sure the guage is reading correct..that sudden rise and drop..with just the heater core coming online really makes it sound liek the termo..take it out and see if it overheats..could be a bad thermo alos..I had one once that was stuck closed out of the box. I test em all in hot water now before installing..keeps the bathroom sinks clearner too...:-)

[smufguy]

when u see the temp gauge shoot up and no smoke comes off of the engine while idling, then ur fine cause ur gauge might be fucked up. Also, u gotta know its not always the units like radiator or thermostat can go wrong. ur sensors go bad sending wrong signals in. Swap em out with a one from the junkyard and see what happens. U better wish its not a headgasket after all the money u spent.

[anchovies]

i have the same problem but not as bad.
It comes down to the coolant switch on the thermostate housing. Did you switch to an aftermarket one. If so it only comes on (turns the fan on) at 3/4 temp. Get one from Honda and see if it solves your problem. Then tell me if it fixes it and help me out :D yes im lazy...
Other thing i can think of is your sending unit.

[2Fast4U86]

Gaaaaaaaaaahhhh!!! I may not be being clear enough!

A brand-spankin' new thermostat, bought at a Honda dealer has been put in this car. I sure hope it wasn't put in backwards, but now you guys have me doubting myself :)

There are no leaks, the fluid level is dead-on. I opened my rad. when refilling it, having not opened it for more than 5 months, and the fluid level was to the top.

What "coolant switch on the thermostate housing"? Not sure of what you're referring to.

Temp. Sensor gauge sending unit might be an idea... the junkyard in this tiny town is a piece of shit tho... they've no competition so they think they're selling gold... I can get stuff for like 1/3 the price in the Bay Area. Gah. But I guess I deal with that.

"that sudden rise and drop.." There is no sudden rise and drop. The temp creeps up to max as the engine warms up, at 85% the fans pop on, cool the engine down, the process repeats. Yeah.

Well, just checking if I was missing anything obvious... thanks for the replies you guys!

2Fast

[Dutchboy]

so the fan does cool it down...but it kicks in at 85%...thats alittle highl..

mine kicks in at half way...
when it reads that its hot is the engine actually really hot??? steaming or anything...

otherwise the guage could be getting the wrong reading...it may be fine .....how long is this after wariming it up that it gets this hot??

otherwise the fan is just kicking in too late...then youll have to replace the switch for it...

id go and check if the hoses on the rad are hot when the gauge says about half...im guessing thats when the thermostat is supposed to open since my fan rarely kicks in and stays at half...

if the top hose isnt hot around half and past that until the fan kicks in then the thermostat isnt opening .....it could be a higher degree thermostat too though..mmmmm,,,,let us know

BEn

[anchovies]

There's one switch on the thermostate housing that turns on the fan. If you look at the thermostate housing, you'll see the ECT sensor (closer to block), coolant switch (next to ECT) and sender unit (below coolant switch, smaller).
Jump the coolant switch, if the fan turns on then you got the right thing. Try a honda one.

[dj99]

FYI, the bigger bullet/spring half of the t-stat goes toward the engine block and the little hole with the dangly thing through it goes at 12 o'clock.

:wave:

[88' Accord Ltd]

I'm having the exact same problem with my car right now too. I thought it was the thermostat too but its not I bought a brand new one and its still doing the same thing. both hoses are hot so coolant is flowing through the engine. I bled the system. I changed the fan relay. I changed the sensor on the thermostat. Im thinking of changine the one under the rad when I try flushing the system. My water punp is good too. But my car does the same thing heats at an idle til about 85% then the fans kick in and cool it down to about halfway. I'm hoping its the sensor under the rad. I dont know. Let me know what the problem is if you fix it.

[anchovies]

Originally posted by 88' Accord Ltd
I'm having the exact same problem with my car right now too. I thought it was the thermostat too but its not I bought a brand new one and its still doing the same thing. both hoses are hot so coolant is flowing through the engine. I bled the system. I changed the fan relay. I changed the sensor on the thermostat. Im thinking of changine the one under the rad when I try flushing the system. My water punp is good too. But my car does the same thing heats at an idle til about 85% then the fans kick in and cool it down to about halfway. I'm hoping its the sensor under the rad. I dont know. Let me know what the problem is if you fix it.

Is that a honda sensor that you changed to?

[88' Accord Ltd]

Yah it was from another accord, the one on the thermostat housing

[anchovies]

Is that other accord's sensor a honda one :D
Just to rule this sensor out from your problems.

[88' Accord Ltd]

Yah I'm sure it is, I changed that sensor twice and had the same result both times, so I dont think its that sensor but maybe they were both aftermarket? The engine dosent seem to be getting like super hot before the fans turn on though, no steam or sizzling or anything so I'm sure its a sensor somewhere. There are only 3 if im correct. One on the carb, one under the rad, and one on the thermostat housing. Thanks though i never considered if the one i got from the junkyard may have been an aftermarket replacement. Is there anyway to tell or do i have to just buy a brad new one from honda to be completely sure?

[anchovies]

Now you have a carb. I think carbs only have an ECT sensor and a sender unit on the thermostate housing.
If I'm right, then you're looking at the wrong sensor. I'm talking about FI thermo housings with ECTsensor, TW switch and sender unit.
So again if I'm right, the TW switch for your car should be the one under the intake manifold (Someone please correct me if I'm wrong).

[rocky2]

I want to share my this with some of you guys with overheating problems. Todays ride....you just can't top off raditors anymore and drive. You need to add coolent to a semi-heated engine(thermo open) from an disconnected upper radiator hose still connected to thermostat side. This will allow caviteies of air pockets to be purged. Trust me. It works. You must be fast with a filled hose to hit the hole with coolent not missed.

[bigpoppa88]

Huh? Somehow I don't understand that procedure.....

[rocky2]

Yeah, I was in a hurry when I did that post.
What I mean is to add coolent to a system that has cooled a bit but not all the way down, then the thermostat will be still open.Do this not by the common method in radiator cap, but by the upper radiator hose....leave radiator cap off,disconnect hose at thermostat side then lift it up as not to fold it,then add coolent directly to the upper hose while being held way up in air till coolent overflows at radiator cap. Then put cap on. then add a little moretill all the way full(hose) . Then quickly put it back on thermostat! Many modern engines delevlop air pockets and never seem to able to fix from overheating. I've did this on a few rides with great success rate.

[dj99]

Isn't that what the bleeder screw on the thermostat housing is for?

[doug]

hey rocky, must be some good acid in your neighborhood this week, just kidding.

[anchovies]

eewwww..nasty green stuff everywhere
hold it up in the air, the coolant will flow to my arm pit!! :D
I don't see the logic in it. hmmm...the thermostate is open, it doesn't matter if you fill it up from the cap side or hose end. Am I right?

[bigpoppa88]

wouldn't it have the same effect by taking the hose off at the rad then pouring the antifeeze that way?

[rocky2]

No! Your getting coolent down into block and out of radiator this way. And purging air out. not acid but asprin. When putting in a new thermostst on a known overheating engine. Stick a asprin into the thermostat. This will allow coolent to flow though it.