Car keeps on overheating---HELP ASAP
 

HI all,

well my car keeps on overheating..this is what i have done so far

- i changed the thermostat with OEM
- changed the rad cuz it was leaking so brand new rad
- did a coolant flush no leaks whatsoever from anywhere.
- Jumped the fan to see if it work..connected it directly to the batt and the fan turns on.
- All the coolant levels are good.

Now i also noticed that when i turn the A/C on it heats up faster. Obviously the car starts overheating at redlights and slow driving and stuff. When i am driving normally the temp goes back to normal.

Also would also this heating up and stuff affect my fuel economy. My last full tank i only got 350 kms out of it.

Need help asap plz.

thanks

I hate to tell you this news:
Headgasket
Mine blew, car still sitting in driveway. I can drive it for about 10-15 mins before it overheats.
You have to replace the gasket.

i can still drive the car...sometimes i can drive it more than an hr before it starts to overheat....as i said as long as i am driving on the road its fine no problems...its when i come to a stop and am stop for more than 2 mins the gauge jumps to hot.

what is usually the cause of blow head gasket...

any other suggestions or things i can try out to narrow down to the possibility of my headgasket being blown??

Jumped the fan to see if it work..connected it directly to the batt and the fan turns on.

Plus you said the temp jumps to the red with a/c on.

Yes the fans works, but what about the relay or switch for it? Does the fan automatically turns on when you have the ac on? Does it turn on when your idling in the driveway for 10 to 15 minutes?

check your compression, do you have any white smoke coming out of your exhaust?

stock engine? boosted?

Anything blocking the front of your rad?

My car would do that too. It would be fine, then I'd stop at a light, and the temp would jump up, I would rev the engine a bit, the fan came on, then temp went down. It did that for a few months but I thought it was the thermostat. I changed the t-stat, same thing, then eventually the fan stopped coming on and no matter what I did the car was in the red. At one point it was bogging and white smoke was coming out of the exhaust.
Trust me, headgasket...

see thsi is somewhat weird....say i park the car overnight and the next morning i come and start it...i can turn the car on and the ac and drive around in the city for good 45 mins to an hr b4 the temp goes up...now mind it the temp only goes up when i stop....doest matter if the a/c is on or not...there is no white some coming out at all and nothing blocking the rad....the engine is all stock and its auto.

where would the rely or the switch for the fan be??? the a/c fan comes on as soon as the turn the a/c on....the rad fan cant really remember when it come on...but it does intermittedly(spell?).

Did you bleed the air out of the system?

Head
Gasket

Call a shop

im thinking head gasket too. Try to see if there are any air bubbles in the system. If it still does it after that. I'd lean towards headgasket. Happened to me before.

the fan switch is on the thermostat housing (unless you have a 88-91 civic/CRX)

lol Andrew I was just going to post the same thing! I had that prob once, changed the fan switch and the car stopped overheating!

dude hows your water pump haha the symptoms fit man, im a apprentice mechanic also do you notice a puffing sound sorta out of your exhaust if som its a head gasket if not then it probably your water pump

coolant temperature sensor maybe?

i had a similar problem not too long ago.. this is what i did..

switched the rad to a dual thickness aluminium rad off ebay and run a 12 inch slim fan..
the rad came to $140 shipped including customs
the fan cost me $80 shipped
and the temp went from over the max line, down to a bit under halfway point...

if it only overheats when your car is idling its your fan.

Since the motor is fine its the switch/relay.

But it may be your hg as well. You said you had a bad rad, well the crankcase pressure is now in your cooling system which likes to kill rads.

First check your fan system though. Then HG

i thought of that too...maybe its the fan.....ok experts ...what can i do to make sure that its the fan or not. i found the rely under the hood.

well there are 4 terminals on the end correct?

It's been awhile since I did one on a honda, but some other manu's label the connectors A B C D .

I believe A and C terminals should not have any contunity when battery voltage is not applied (so check the ohm level, should read infinite)

Then you apply battery voltage to B-D terminals and there now should be continuty between A-C terminals.

If this sounds a bit confusing download a honda service manual from hondahookup.com and check it out yourself. Maybe they have a quicker/better way of testing it. Or maybe I mixed up the terminals.

I guess my post just gives you an idea of what you have to do.

Only tools needed is an ohmmeter and a few pieces of wire

G/L

Actually.. why dont u check if your fan comes on. Turn on your a/c (obvs make sure its not on hot) and let the car idle. Within 10 minutes it should definately turn on. Put as much load as you can on it, radio on, headlights on, rear defoster, even revv it up a bit at first to help it get to O/T. Then let it idle and the fan should turn on. If it doesnt , then investigate the switch/relay.

Theres also a fan switch, like zeeman stated. If the fanswitch is pooched the fan wont get the proper reading. I'm sure there are some resistance specs on the switch itself. Again, refer to the manual

Your learning but your wrong on this type of vehile. Waterpumps usually lose their fins when they have plastic impellers. This is quite common with the 2.5l duratec ford motor. As hondas use metal impellers it would be an almost impossiblity that the waterpump has lost its fins. The best way to tell if a waterpump doesnt flow anymore is taking one of the rad hoses off (the upper) and run the vehicle to see if coolant flows through it.


The problem is more than likely a headgasket. Pull out the plugs, pressurize the system and look down the clyinders. Most likely they will be wet with coolant.

If this doesnt work make sure your rad cap is also good. Ive seen headgaskets changed and it was only a rad cap as the culpret.

ouch.

I've seen mechanics change rads, use the old rad cap and the problem is still there. Then they test the cap.. It's one of the most over-looked parts of the cooling system.

You can actually physically test it yourself without any special testers. You can physcially look at the seal and see if its torn or swelled up. Also but your thumb on the cap spring, and squeeze/push it down. Does it go down very easy? If so.. it's most likely bad. Obviously these arent proper tests, but its a quick way to see if the cap may be bad