Engine overheating

Check the radiator if clogged and the water pump if both okay could be air in it try bleeding it don't work get it block and pressure tested to include the radiator cap

Here is a guide to help you:

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please let us know what happens.

Cheers

Thanks.. it turned out to be the fan switch is bad.. so I used a jump wire and fixed the problem. :-)

Nice work, we are here to help, please use 2CarPros anytime.

Cheers

Engine Cooling problem
1995 Honda Civic Automatic 116000 miles
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I have a 1995 Honda civic DX coupe with 116K miles on it. Bought it about 15K miles back last year. About a couple of months back, I had gone out of town. It was a hot summer day, so the AC was on and there was a lot of uphill driving. The engine started heating up. I let the car cool down, checked the radiator and the resrvoir and saw it was very low on coolant. So bought coolant (Zerex pre-diluted, which mentioned Honda as one of the brands it would work for) from a gas station, and topped up the radiator and the reservoir (to the MAX level). Drove back home (about 50 miles), and there was no problem.

After that, for the next 2 months or so, was driving only in town (I live in a small town, so even the longest drive is maybe 5-6 miles at a stretch). No problems with overheating or anything.

Then last weekend, I was on a long trip again. Another hot day. Was on the highway and it was fine. We didnt have the AC on, and the windows were rolled down. Took an exit for some coffee, and the temperature gauge started climbing up. Checked the coolant level and it was fine (in fact coolant in the reservoir was above the MAX mark). I noticed that the cooling fan wasnt working. So I assumed that was the problem. Let the car cool down, continued with my trip on the highway. The temperature was OK as long as I have driving at 55 and above.

But an hour later, when the traffic slowed down due to road work, the gauge started climbing again. Luckily, the traffic didnt last long, so we were back at high speed and the gauge went to below the midpoint. Whenever the car overheated, I would pop up the hood and the fan would usually not be working.

So I googled fan troubleshooting tips and found advice on several forums. Took the connector off, shorted the pins and the fan started running, so the fan motor was OK. One possible reason being mentioned was thermoswitch and/or thermostat being bad. It was mentioned on a couple of forums that I should check to see if the lower hose was cold. It was not. After keeping the car in idling for 10 minutes, both the upper and lower hoses were hot. The upper one was hotter, but the lower one was hot too. So I took this to mean that there probably wasnt a problem with the thermostat or thermoswitch.

Next, I read that air pockets could be stopping the fan from coming on, so I should purge the system. Did that. Fan came on twice while the car was in idling with the reservoir cap open. So I thought now that the fan was working, things were fine.

Took it for a test drive. Took an exit and slowed down after 45 mins of driving, and there we go again. The gauge started climbing up. Popped open the hood, and saw the the fan was actually working. Both the lower and upper hoses were warm (though like I said, the lower was was a bit less warmer). Yet the gauge kept creeping up. Drove back again, maintaining high speed and the temperature remained fine.

So here are my questions -

1. Is it still possible that something is wrong with the thermostat or thermoswitch? The fan is coming on now, and the lower hose is not cold. I read somewhere that if the thermostat is busted, the engine will pretty much start overheating in minutes, and won't cool down even if you are at high speeds. Dunno if this is right.
2. There are no visible leaks. The coolant level is fine. I dont see any leaks from the water-pump either, but could that be a problem?
3. In general, what else, apart from fan problems, could cause this intermittent at-low-speeds-only overheating? Wherever I saw people saying that they had this problem, the people responding invariably said it was a fan problem. But now that the problem is occuring despite my fan running, what else should I check?

I am taking the car to a mechanic today for a diagnostic check, but would also appreciate some inputs here in case he cant figure it out.

Thermostat is a possibility . Also fan relay may be working intermittently.

Thanks. Oh, and today I need to drive 4 hours to pick my mom up from the airport. I was wondering, if intermittent fan operation is the problem, is it advisable to jump the connector pins so that the fan will stay on all the time, as a temporary fix? Or will keeping the fan on all the time that I am driving, damage the fan?

It would be O.K. but if most of trip is highway I would not and let ram air do the job. then as you approach airport jump then. But if the thermostat is the culprit this method may not work.
Good luck
If you have a working AC with it on fan will run all the time

Thanks.

Here is some brand new information from the trip to the mechanic. He noticed that the coolant level in the radiator was not up to the neck, although I had topped it off just yesterday (the reservoir level was good though). He added some more coolant and it took very little (maybe 2-3 ounces - 60-90 ml) to top it up. So it was not like the coolant had run out fully, but some of it had gone somewhere.

So he hoisted the running car up with a cardboard under it to see if there were any leaks. Kept it like that for over half an hour and not a drop of leak. He also checked the oil cap and the dipstick to see if there was any green or white coloration caused by the coolant leaking into the oil, and that didnt seem to be the problem either. He also looked at the exhaust to see if any white smoke was coming out, indicating the coolant going out through the exhaust, and that wasnt the case either.

He has asked me to leave the car with him for a day to test this further. Any idea where else the coolant could be going?

Engine Cooling problem
1995 Honda Civic 4 cyl Manual

would a not working cooling fan cause shift problems

Hi gauravs,

You should never have topped up with coolant of a different brand. Most coolants are not compatible and should not be mixed. They would cause clogging up of the cooling system.

What you are facing is an inefficient cooling system and most probably caused by,

1. Weak water pump.
2. Partially clogged radiator or coolant passages.
3. Air trapped in system.
4. Faulty thermostat, stuck in partially opened position.
5. Faulty radiator/condenser fan. (Both fans should be working when AC is on or fan switch is activated.)
6. Faulty/inconsistent fan thermoswitch or loose wire connections.

If reserve tank level is higher than max, check radiator cap condition, lost coolant might be found in reserve tank.

HI there,

No it will not, check the clutch operation and the gear box oil level.

mark (mhpautos)

What do you mean by clutch operation, it is an automatic test drove it Thurs, bought it Friday, drove home 40 minutes road great, parked overnight Sat drove it only 2 houses away to get gas, overheated immediately pulled over, radiator cooling fan was not on put in Reverse and it felt like it was in neutral, I know the fan could be the fuse or the motor, that's not that big a deal, but the transmission? It is an Automatic and when I bought it the guy said his mech. said the throttle idled to high and it needed proper adjustment. Driving wise it went thru till, at 35rpm's it didn't wanna go until it was put into d3? any help would be greatly appreciated?

Hi there,

In your first post you wrote......Engine Cooling problem
1995 Honda Civic 4 cyl Manual.......

As you say it is actually an auto, i will give it some thought and get back to you soon.

Mark (mhpautos)

Well, Just picked up from a service guy, the cooling fan is fine, just unplugged, on the drive home if I gave it light gas at 40 rpm it was fine, but if to much I had to go to d3 then no problem, got home, absolutely no reverse? My next thing is do I need to take to a tranny guy? I don't know where or how to check the gear box oil level. Thanks for you help so far

Hi there,

With the trans at normal operating temp engine running and in park, check the oil on the transmission dip stick, the oil should be at or near the hot reading, if there is no reverse, i would be getting this checked by a trans specialist.

Mark (mhpautos)

Engine Cooling problem
1995 Honda Civic 4 cyl Front Wheel Drive Automatic 140,00 miles

Replaced thermostat, radiator and cap, upper and lower hoses, water pump, timing belt.

When idling, temperature remains normal, cooling fans come on/off. After a couple of days of driving, loss of coolant, overheats, pressure builds in radiator. Had block checked for blown head-gasket. Checks out ok at this time, no hydrocarbons in cooling system.

Please help with advice...thank you

Hi Rosie,

After replacement of parts, was the cooling system properly bled of air trapped?

Is the reservoir full or dry when you noticed coolant losses?

Was any pressure test carried for coolant leakages apart from the hydrocarbon test?

Hi MDhoff,

The transmision is bad.

You do not have reverse and 4th speed as the 4th clutch has failed. This clutch is shared both by reverse and 4th.

Yes, the air was properly bled. When it overheats it blows back into reservoir. No coolant leaks to be seen. No recent pressure test.

The symptoms indicates any of the following and further needs to be carried out.

1. Blown head gasket.
2. Bad radiator cap or incorrect specifications.
3. Air trapped in system.
4. Clogged radiator or thermostat.

My car is having the same problems??? I have done all of Rosie had done.....Except it was about a year ago that i replaced the rad, Thermostat and all hoses.

Rosie Did you figure your problem as of today???

thanks

Hi andykyn,

Do you have coolant losses, both from radiator and reserve tank?

Fans working?
For automatic, both fans should operate when temperature increases or AC is turned on.

I have both losses from both rad and resovoir also...It is not leaking on the ground at all..I check the ground all the time and nothing on the ground. The fan is coming on as normal cycling on and off. I have heat inside the car on all ???

Any help would be a great help..Thks

MY OLD 95 CIVIC ENGINE HAD A BLOWN HEAD GASKET AND WAS OVER HEATING SO I DID A WHOLE ENGINE SWAP. I REPLACED IT WITH THE SAME ENGINE (1.5 NON V-TEC) BUT FROM A 93 LOW MILAGE. IT RAN LIKE A CHAMP FOR ABOUT A WEEK AND THEN IT STARTED OVERHEATING WHEN I WOULD PUT IT IN PARK OR STOP AT A LIGHT OR ANY SORT OF BRIEF STOP. THE FAN KICKS IN FINE, IVE CHANGED THE WATER PUMP, CHECKED THE HEATER CORE, REPLACED THE THEMOSTAT TWICE, RAN IT WITHOUT A THERMOSTAT, LOOPED THE HEATER CORE HOSE, NEW RADIATOR, AND IT STILL KEEPS OVERHEATING I DONT KNOW WHAT TO DO OR CHECK?? CAN SOMEONE HELP ME???

are you using the correct coolant?....just the first thing that came to mind

You are going to need a head gasket replacement.

Honda engine head gaskets fail this way often on older cars. What happens is the combustion pressure bypasses the gasket into the cooling system. This causes air pockets and lack of coolant circulation. If you bleed the air out again, it will not over heat for a while until the air pocket builds again.

This is the reason I was told by someone else. Just wanted to add that. Hope it helps.

YEAH I USED THE RIGHT COOLANT BUT IT HAPPENS MAYBE AFTER HALF HOUR OF THE CAR BEING IN USE ITS BUGING ME TO DEATH I DONT KNOW WHAT TO DO I WAS THINKING MAYBE CHANGING ALL THE SENSORS LIKE THE TEMP SENSOR AND THE SENDING UNIT. CUZ I DONT KNOW WHAT ELSE TO DO. AND I DONT WANT TO GET RID OF IT

to verify a head gasket issue you can do a test for combustion gases into the cooling system. It is a dye that is put into a cylinder and one one end of the cylinder is hooked to vacuum and the other rests in the radiator. The dye will turn a different colour is combustion gasses have been pushed into the cooling system.

hum, tough problem here are a few sugestions.

1. check sensors.
2. radiator cap, seal broken.
3. most honda engine timing is important to the over all performance of the car this would include water pump timing. Yes water pump timing check it out.
4. cooling fan blades cracked or broken.
5.and yes even ignition timing.

check these items out and get back too me.

PEACE OUT!!!!!

When both radiator and reservoir are losing coolant, there is a leakage somewhere. Get a pressure test done to detect the leakage. Sometimes leakages are too minimal and would not should much visibly.

Head gasket failure would have the reservoir overflowing rather than depleting.

Engine Cooling problem
1995 Honda Civic 4 cyl Front Wheel Drive Manual 200000 miles

I'm driving a Honda Civic. When I'm on the road with hot temparature, travelling for about a 100 miles, my engine signals an overheat. I checked the reservoir level after 15 minutes and it is normal. I checked my radiator and it has no leak and coolant level is still ok.

do you notice if the fans come on?

Yes, my fan is ok. Also my thermostat is new

ok your gonna change the engine coolant temperature sensor, and you should be ok. keep me posted

1995 Honda Civic 4 cyl Front Wheel Drive Automatic 161000 miles

I have replaced the radiator, thermostat, water pump, and the anti freeze hose has been fixed from bursting.The fan also works. The car is still overheating and melting my wires and the covers to my timing belt. Why is it still overheating???

Possibly a bad headgasket. Have it leaktested.

I was told to have it pressure tested and the next thing could be a blown head gasket.

Engine Cooling problem
1995 Honda Civic 4 cyl Front Wheel Drive Automatic 160000 miles

My 95 Civic (1.5 liter 16 valve SOHC) is consistently overheating. I cannot find any leaks. No coolant in the oil. At first i thought it was the head gasket, so I have replaced it. When it overheats, it blows gases back into the overflow. I can relieve the pressure by opening the air bleeder on the engine outlet housing. I have bled the air repeatedly then topped off the radiator each time. Any ideas?

So when it overheats it blows coolant into the overflow tank? Sounds like a headgasket.

When you replaced the gasket, did you re-surface the head? and check for a warp block deck? If not, that's your problem.

[quote:a667d75868="F4I_guy"]So when it overheats it blows coolant into the overflow tank? Sounds like a headgasket.

When you replaced the gasket, did you re-surface the head? and check for a warp block deck? If not, that's your problem.[/quote:a667d75868]

Yep, did all of that. I'm not getting exhaust gases in the coolant.