dockersguy

My 92' accord overheats when I idle after getting off of the freeway or driving up a hill.

I have replaced the upper/lower radiator hose, thermostat, radiator cap, radiator, and coolant. I also have flushed the cooling system and tested both thermo switches A and B, condenser fan relays, radiator fan relay, fans, and temperature sending unit, temperature gauge, a/c diode, and cooling timer unit.

What works: Radiator fan comes on after I turn off the engine. I have jumped both the condenser and radiator fan and they both come on. When the car overheats I turn on the heater full blast and step on the accelerator. This brings down the temperature back to normal. My car doesn't USUALLY overheat on the freeway (rarely). No coolant leaks under the car or in the engine bay. Water pump doesn't make any funny noises. Not loosing any coolant either. Ignition timing is at 17, 2 degress retarded.

What I have noticed: During idle after getting off the freeway or driving up a hill I noticed that the upper hose is hotter than HELL and the lower hose is only warm. Warm to the point where I can keep my hand on it without worry of burning it. It feels like I can keep my hand on it forever. It's not cold or cool. Both hoses are very firm. The car at idle will then start to overheat. At this point, the fans have not turned on. I will accelerate and turn on the heater. The temperature drops back down to normal. About 10 seconds later, both fans will turn on and the car will never overheat again. Both fans at this time will turn on and turn off regularly.

If you guys have any questions for me about my problem please post them or
e-mail them to me at sendittome@san.rr.com Thank you.

Nick H

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dockersguy &raquo;</TD></TR><TR><TD CLASS="quote">[Ignition timing is at 17, 2 degress retarded.
</TD></TR></TABLE>

that'd be 2 degrees advanced i believe, as stock is 15...

well, it sounds to me like you have a bad (non functioning) water pump...if the lower hose is only warm, it sounds like coolant from the radiator is not being pumped into the engine bay...both hoses should be hot enough that you shouldn't be able to place a hand on it w/o burning yourself...hope this helps...

Schmitey

I second that...

but no coolant leaking from the pump, weird

Have you flushed the entire system, including taking out the engine plug?

dockersguy

I have flushed the entire system, but didn't unscrew the engine plug. No coolant leaking on the ground, but I haven't inspected the weeping holes on the water pump yet. That seems like a task where I could really screw things up if I couldn't get the belts back on. Also I have had my timing belt and water pump replaced 15k miles ago. The warranty on the work and parts has just expired. If you guys have any further questions, feel free to ask. Thanks again.

dockersguy

Anyone else have any other ideas or suggestions? Thank you.

accordnut

I think the fans are not coming on early enough. Try this, start the car and let it warm up. Hold the rpm at 2500 until the fan comes on. Check the guage temp. If the guage is above half I would replace the fan switch.

Bullethole

Make sure you have no air in the system. The fill procedure must be followed or air pockets will create hot spots and possibly cause the problem you described. My 94 manual outlines the steps so this will not occur.

m0t0rhead

Your Coolant Temp Sensor tells the fans when to come on. When you're at idle (not moving) you have no airflow over the radiator unless the fans are on. That would explain why you are overheating.

The fans are always on with the a/c or heater engaged.

Let me ask you a question, when you're overheating at idle, is your HVAC on or off ?

If they are all off, my bet would be on the coolant temp sensor.

If it's on, it's sounds to me like you have a circulation problem.

JimBlake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">Your Coolant Temp Sensor tells the fans when to come on... </TD></TR></TABLE>All of my HondAcuras have a separate fan switch. The ECT sensor is for the ECU, and that doesn't control the fans. Did they do it differently in '92?

dockersguy

Yea I'm pretty sure that I bled the cooling system correctly. With the radiator cap off and the bleed valve open, I fill the radiator until there is a steady stream of coolant coming from the bleed valve then i close the bleed valve. I also have been checking the system for any cold/cool spots but haven't found any. I'll bleed the system again just to make sure.

When I'm overheating the HVAC is off. What you said is totally correct about the temperature sensors. The only thing is that when I checked the temperature sensors in boiling water with a multimeter and a thermometer the circuit closed at the right temperature. It would make sense that the temperature sensors are not completing the circuit and not allowing the fans to come on, unless there was a break in the circuit else where, but all that have been checked and everything is good. Also like you said, it could be circulation problem too, if the coolant reaching the temperature sensors wasn't hot enough then the circuit would never close. Any ideas anyone on how to check if the water pump works? I mean without having to check the weeping holes? I'm not experienced enough to take the pulley off. I don't want to mess anything up. Thanks for all the input so far. It's really helps me narrow down possible causes.

dockersguy

I think it's separate. I've been using the terms temperature sensors and fan switches interchangeably. The fan switches I've been checking does nothing else, but close the circuit when it's hot enough. I've also checked the temperature sending unit...The sensor that tells the gauge where it should be at. I don't know if this also goes to the ECU. Is there a sensor or switch that I have been missing?

JimBlake

Mine have a fan switch (2 wires), a sender for the gauge (1 wire), & a sensor for the ECU (2 wires). They don't share information, & the fan switch is the only one that has anything to do with running the fans. Unplug the fan switch & jumper it's plug with a paper clip. Key on, that should make the fan(s) run.

When it's cold, squeeze the radiator hoses. They feel different & you'll hear sloshing noises if there's air pockets in either hose. All you should hear is that funny little pin-thing in the thermostat. When you bled air out, was the heater set to full-hot?? Air pockets can hide out in the heater core.

Water pumps pretty much always pump water. If it leaks you'll find puddles on the ground. If the bearings go bad it makes noise, but it should still pump water.

Elvis1977

Did you use a HONDA factory thermoatat? Did you put the jiggle pin on the thermostat in it's correct position on the housing?

m0t0rhead

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">All of my HondAcuras have a separate fan switch. The ECT sensor is for the ECU, and that doesn't control the fans. Did they do it differently in '92?</TD></TR></TABLE>

The fans come on when the coolant reaches a certain temp. based off of what the CTS reads. So, technically, it DOES control the fans.

You are mistaken.

I run a shop, we fix these everyday.

If the sensor is good, I would check the circuit.

m0t0rhead

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dockersguy &raquo;</TD></TR><TR><TD CLASS="quote">
When I'm overheating the HVAC is off. What you said is totally correct about the temperature sensors. The only thing is that when I checked the temperature sensors in boiling water with a multimeter and a thermometer the circuit closed at the right temperature. It would make sense that the temperature sensors are not completing the circuit and not allowing the fans to come on, unless there was a break in the circuit else where, but all that have been checked and everything is good. Also like you said, it could be circulation problem too, if the coolant reaching the temperature sensors wasn't hot enough then the circuit would never close. Any ideas anyone on how to check if the water pump works? I mean without having to check the weeping holes? I'm not experienced enough to take the pulley off. I don't want to mess anything up. Thanks for all the input so far. It's really helps me narrow down possible causes.</TD></TR></TABLE>

Has the water pump ever been changed ? How many miles do you have ?

There is no real way to tell without taking it apart.

JimBlake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">The fans come on when the coolant reaches a certain temp. based off of what the CTS reads. So, technically, it DOES control the fans.</TD></TR></TABLE>OK, I guess I don't know '92 cars...

My '95 & '98 cars have a fan switch in the T-stat housing. Honda called it a Coolant Temperature Switch. Electrically, it's a normally-open SPST, so they called it a switch not a sensor. It's not wired to the ECU at all, according to my Helm books. The Engine Coolant Temperature (ECT) sensor is wired into the ECM, and doesn't control the fans. So maybe we're both saying the same thing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Elvis1977 &raquo;</TD></TR><TR><TD CLASS="quote">Did you use a HONDA factory thermoatat? Did you put the jiggle pin on the thermostat in it's correct position on the housing?</TD></TR></TABLE>This is good. Mine looks like it only fits one way, but ??

dockersguy

I jumped both the condenser and radiator fans and they both work. I set the dial to heat when I was filling and bleeding the cooling system. Now that you mention it, I do hear sloshing noises when it's cold.

I bought my thermostat from Kragen and I did install it correctly. The jiggy thing on top, LOL.

My 92' Accord has 177k miles on it. I just had all the belts and water pump replaced 15k miles ago.

I took the car into the shop today and the mechanic couldn't get the damn thing to overheat. They diagnosed the car for 4 hours. The ran a pressure test, block test, checked the water pump, and couldn't find any reason as to why my car would overheat. They even bled the system again just to make sure. I got my car back now and I can't make it overheat either. It was overheating yesterday and for a month before that, but now it won't overheat. The only thing I did between yesterday and the time I dropped off the car at the shop was to bleed the system again. I can only come up with this conclusion. The very first time I bled the system it was on flat ground. Then it overheated. The next several bleeding sessions it was on an incline. Perhaps there was air left in the system and when I tried bleeding it the second time and the subsequent bleeding sessions on an incline didn't actually bleed anything at all. Although through trouble shooting using the Helms manual my friend and I did come across a bad A/C diode and some wires on the condenser fan relays that were loose inside the wiring harness. This prevented my fans from coming period. The mechanic concluded that I could have a very tiny head gasket leak or a sticky thermostat. The tiny head gasket leak could go by undetected and I wouldn't know it until it was full blown. The sticky thermostat is a possibiltiy, but even with one it would at least make it overheat a little. He didn't see any of that. So, in the end I guess my car fixed itself or I got lucky with the bleeding. I'll being watching the temperature gauge very closely during the next several days. I'll update you guys if it overheats again.

Thank you so much for all your guys' help. You guys ROCK!

dockersguy

Sorry guys, I spoke too soon. I drove the car for a few hours without it overheating. I even heard the fans come on when I was idling. BUT THEN.... After coming off of the freeway and it overheated at a traffic light. I was listening for the fans, but they never came on. I never felt the fans either. The car usually shakes a little when the fans come on. When I got home the car overheated again, so I jumped coolant temperature switch A and both fans came on. The temperature dropped down to normal. I was told that old wiring can sometimes fail when exposed to heat. I guess the wiring is just fine then. Coolant temperature switch A is located before the thermostat right on the thermostat housing.

So, my question is coolant temperature switch A at fault OR is it the possible sticky or maybe stuck thermostat building pressure and not allowing fresh coolant to flow pass coolant temperature switch A? Any other possible causes? These two parts are pretty cheap to replace even from the Honda dealership. Thanks again guys...

alb_accord

check the system preasure. and change the swich.
next time when the car overheats just put the AC on and see if the temp goes down.
also make sure of the other hozes don't have holes into them. eventhough u dont' see any coolant driping the little hole might get air into the system(from experience)

dockersguy

hey guys, the overheating problem is fixed for sure now and I know exactly what went wrong. I bought a brand new Stant brand thermostat and replaced my old one. THIS WAS THE PROBLEM. The Stant thermostat must have been defective because today I bought a HONDA OEM thermostat and it fixed my overheating problem. I drove it on the freeway for like 20 mintues and did lots of stop and go driving and didn't have any problems. The needle was ROCK SOLID, didn't even twitch. I guess the Stant brand thermostat was sticky or just plain SUCK so it didn't allow for enough or any coolant to pass by coolant temperature switch A, thereby not closing the circuit and triggering the fans. Gonna call Stant and get my money back. One good thing, that came out of all this is that now I'm more knowledgeable about my cooling system and my friend and I also found some loose wires in the wiring harness that made the fans work intermittenly. ANYWAYS, as in my previous post. You guys have been very generous to me about helping me fix my overheating problems. Thank you so much. "You meet the nicest people on a Honda"

m0t0rhead

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dockersguy &raquo;</TD></TR><TR><TD CLASS="quote">hey guys, the overheating problem is fixed for sure now and I know exactly what went wrong. I bought a brand new Stant brand thermostat and replaced my old one. THIS WAS THE PROBLEM. The Stant thermostat must have been defective because today I bought a HONDA OEM thermostat and it fixed my overheating problem. I drove it on the freeway for like 20 mintues and did lots of stop and go driving and didn't have any problems. The needle was ROCK SOLID, didn't even twitch. I guess the Stant brand thermostat was sticky or just plain SUCK so it didn't allow for enough or any coolant to pass by coolant temperature switch A, thereby not closing the circuit and triggering the fans. Gonna call Stant and get my money back. One good thing, that came out of all this is that now I'm more knowledgeable about my cooling system and my friend and I also found some loose wires in the wiring harness that made the fans work intermittenly. ANYWAYS, as in my previous post. You guys have been very generous to me about helping me fix my overheating problems. Thank you so much. "You meet the nicest people on a Honda"</TD></TR></TABLE>

If you use aftermarket parts, you're asking for trouble. I'm glad you got it fixed.

Honda parts

92hondaaccord

I am having a mild overheating problem where my fans come on later than they used to. I have a post currently going on this and am waiting some more help on the issue. Bassically, I have replaced the temp sending unit, CTS, and both radiator and condenser fan switches. However the guage still goes up to 3/4ths and then the fans turn on and cool it back down. Stays at normal middle gauge with AC running due to fans staying on. Also, no problems when driving with air flow. I have also changed the thermostat with a honda one.

the only non honda part was the temp sending unit, which I am going to change today.

Can anything delay the fans turning on other than the radiator fan switch on the thermostat housing?