Overheating

1986 lx. As of late I have experience overheating.

1.-Engine does not overheat in the morning on my way to work, 30 min drive. Outside temp 60 -65. Stays below 1/2.

2. Engine overheats after work , when the outside temp is 95 or so. Same drive, 30 min.

3.- Coolant reservoir bubbles up and spills coolant when it overheats.

4.- Rust in radiator with possible trans mission fluid, or maybe oil.

5.- Fans come on? To be tested.

6.- Thermostat and radiator cap replaced, thermostat installed correctly, with vent hole up.

7. No smoke from exhaust.

8.- No coolant in oil

Next to do is test cooling fan. Replace radiator and fan if not working. Replace collant temp sensor. Do a leak test for blown head gasket.

Engine runs smooth and no noises from the engine. Oil level is full, and clean. No coolant.

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Originally Posted by 1989accordaz

1986 lx. As of late I have experience overheating.

1.-Engine does not overheat in the morning on my way to work, 30 min drive. Outside temp 60 -65. Stays below 1/2.

2. Engine overheats after work , when the outside temp is 95 or so. Same drive, 30 min.

3.- Coolant reservoir bubbles up and spills coolant when it overheats.

4.- Rust in radiator with possible trans mission fluid, or maybe oil.

5.- Fans come on? To be tested.

6.- Thermostat and radiator cap replaced, thermostat installed correctly, with vent hole up.

7. No smoke from exhaust.

8.- No coolant in oil

Next to do is test cooling fan. Replace radiator and fan if not working. Replace collant temp sensor. Do a leak test for blown head gasket.

Engine runs smooth and no noises from the engine. Oil level is full, and clean. No coolant.

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Any leaks? Does it specifically heat up when you come to a stop? Are your hoses cracked at all? Check your connectors!

If you have oil in the coolant, that's either a head gasket failure, or a radiator failure. Confirm it with a rad pressure test before spending a lot of time and money, of course. Do you have coolant in the trans oil or PS reservoir?

No coolant or oil leaks. The temp gauge gradually climbs up, even while driving. All hoses Ok. Will check for coolant in the trans oil. Will do the rad pressure test after I confirm the cooling fan is comin on. Thanks for the tips, I'll follow up on my findings. I suspect the radiator because of the rust, I hope is not the head gasket.

Drove 30 min to work today, outside temp 62 degrees. Temp gauge at 1/4 all the way.

Ok, so thermostat works, and it doesn't overheat when it's cool outside. Check if your fans turn on.

Is this city driving? Or does it overheat while you're moving? It sounds like your radiator is plugged/clogged inside and may need to be replaced.

If you fans work and/or it overheats while moving then the water isn't flowing.

Which could be the water pump if it's due for replacement, or the radiator. I'm leaning toward the radiator. It sounds like the coolant is pretty filthy though.

Drain it all and replace it with distilled water, it's cheaper than coolant and will work just as well short term while you test things. See if that helps any.

btw, you should never have oil in the coolant. So check your trans to make sure it's not mixing. You do not want to ruin your transmission.

City driving, Cooling fan is working, I jumped the coolant switch at the radiator and the fan came on. I replaced all coolant with new coolant, I replaced the radiator fan switch, purged all the air out and the fan never came on. Had to shut it down because it got to 3/4. Checked the coolnig fuse under the dash and is ok. Checked the cooling fan fuse under the hood and is ok, fan timer ok. I swapped the relay with one from my 89 lx and fan still not coming on. So all points to the fan not coming on.

The radiator needs to be replaced, is rusted. I bought a radiator from Autozone, had to rerurn it as one of the cooling lines for the AT doesn't fit right.

I wonder if the thermo switch I bought from Autozone is not to specs. Will stop by Honda and see if they have one.

Quote:

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Originally Posted by 1989accordaz

City driving, Cooling fan is working, I jumped the coolant switch at the radiator and the fan came on. I replaced all coolant with new coolant, I replaced the radiator fan switch, purged all the air out and the fan never came on. Had to shut it down because it got to 3/4. Checked the coolnig fuse under the dash and is ok. Checked the cooling fan fuse under the hood and is ok, fan timer ok. I swapped the relay with one from my 89 lx and fan still not coming on. So all points to the fan not coming on.

The radiator needs to be replaced, is rusted. I bought a radiator from Autozone, had to rerurn it as one of the cooling lines for the AT doesn't fit right.

I wonder if the thermo switch I bought from Autozone is not to specs. Will stop by Honda and see if they have one.

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If the radiator is not that old then you will have to find the source of the rust. Most likely a freeze out plug or the coolant pipe going across the back of the motor. Over heating with higher ambient temps usually is the radiator is marginally cooling.

My car the fan never come on the car doesnt get warm enough it runs about 1/4 way on the gauge. Very few times have I ever heard them come on and I was out west at very high altitude. I need to reprove that to my self and rig a light or something when they come on. They do come on with the AC on of course. Usuing the AC button on the dash should force the fans on weather you have working AC or not. That save a bunch of xtra wiring.

ac has been retrofitted, but is currently not working. That is how I bought it last year. The condenser fan and the cooling both work when jumped or powered directly to a 12v source. No coolant leaks of any kind. I need to find the source of the coolant fan not coming on, replace the radiator is next, as soon as I find one that fits. I am also replacing the thermo switch with a genuine honda. It is puzzling though.

Water pump or you have a blockage somewhere that is causing the coolant not to flow well. I've had that happen with old hoses that get buildup in them, think of a blood vessel full of fat deposits, same concept.

And I think the culprit is my radiator, because when is cool outside, it does not overheat, as long as I am moving. Hoses top and bottom, do get hot. The fins on the radiator look in bad shape when I look down on it with the cap off. I am in the process of getting a new radiator. The one I got from autozpne had the AT line protruding too much, not usable. The old thermoswitch had coat of hardnend rust. Almost as if rhe previous owner had the wrong mix in it, more water than coolant it seems.

I'm like 90% sure it's your thermostat. Replace that first, it's cheap and easy anyway.

First things I replaced was the radiator cap and thermostat. Will continue to do some troubleshooting as soon as I am able.

Is you gauge working properly?

Snooz, I am up and running! Had to take the time and retrace my steps and aproach. It ended being the new radiator thermoswitch, defective out of the gd box.

I kept the old one, and I remeber it had a hard coat of something on it, rust maybe? I cleaned it ,tested it with boiling water, and it showed continuity as it was supposed to. I did the same thing with the new one and it never did get continuity.

So I cleaned and reinstalled my old thermoswitch and the fans finally came on.

It never ocurred to me that the brand new radiator thermosensor was faulty.

Thank you all for your advise,

I will replace my radiator soon, has a copper core and I believe it is the source of coolant contamination that caused the thermosesnsor to be coated with crap! Hearing the fans come on was like music to my ears.

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Originally Posted by 1989accordaz

Snooz, I am up and running! Had to take the time and retrace my steps and aproach. It ended being the new radiator thermoswitch, defective out of the gd box.

I kept the old one, and I remeber it had a hard coat of something on it, rust maybe? I cleaned it ,tested it with boiling water, and it showed continuity as it was supposed to. I did the same thing with the new one and it never did get continuity.

So I cleaned and reinstalled my old thermoswitch and the fans finally came on.

It never ocurred to me that the brand new radiator thermosensor was faulty.

Thank you for your advise,

I will replace my radiator soon, has a copper core and I believe it is the source of coolant contamination that caused the thermosesnsor to be coated with crap! Hearing the fans come on was like music to my ears.

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Nice!!! Good stuff, man

You should be stoked. My '93 does the same thing, but it's because of a super-old, very tired engine.