I noticed, on Friday, that the engine temp needle on my 96 Accord was "in the red". My heart sank, but I started to notice that it was beginning to drop before my eyes. I watched it go back down to normal, and then back up again...

...so, I replaced the thermostat this weekend, and on my way to work it did it again... it went up to the red zone...

Can anyone shed light on what might be causing this? I'm praying it's not a bad water pump. If the pump was bad, it wouldn't be able to cool down at all, correct? Could it be something that trips the pump to turn on?

Any help would be appreciated.

Thanks.

 

I would make sure the fans are coming on.

 

I should've mentioned that the fans do turn on, yes.

 

it can cool with a bad water pump depending on the severity of it. Usually it will be able to cool while at throttle (not idle) or while at a higher speed. BTW its a pic of my water pump on my grand prix a couple of months ago which had similar symptoms as yours. Never leaked out of the weep hole because it was clogged with gunk.

 

also did you bleed the system?

 

I see no problem with that pump.

 

Looks like a biker club decal.

 

Do you mean when I replaced the thermostat? No, I didn't, since I never have when I changed thermostats on my previous cars.

 

The bleeder valve is on the thermostat housing. Just idle your car and crack that open until coolant comes out, then close it.

You would be hoping that your original problem was your thermostat and that 'cause you didn't bleed the thermostat isn't opening up. When you bleed the air out, then hopefully the fan will turn on.

http://www.hondaautomotiveparts.com/...ry5=WATER+PUMP

If it doesn't, then my next choice would be the thermosensor(14) which tells the fan to turn on when the car is running. The thermoswitch(15) tells the fan to turn on when the car is off.

Instead of buying the thermosensor, you could jump the connector first, though I usually will just buy a new one and that solves it.

 

it would be a good idea to have someone with a live data scan tool read the ECT while the needle is moving up. that will rule out a bad temp sender for the gauge (or tell you it's bad).

 

Obviously, I'm sure you know you can get those sensors at any auto store, Kragen, Autozone etc etc.

 

Thanks for the suggestion. I'm going to take it to my uncle's mechanic (whom he swears is honest) and have him take a look at it. He gave me a good piece of advice on the phone: check to see if the upper and lower hoses are different temps to see if the water is flowing....

I'll let you guys know what I find - I'm very grateful for everyone's help thus far... if you have any more ideas please keep'm coming!

 

So phootbag was right - only one of the fans was coming on. Another pseudo-mechanic friend of mine said that only one comes on and the "other" was for the AC only... turns out the AC one wasn't turning on at all (ever!) and it does turn on to cool the car.

$175 later, with a new fan installed, the overheating seems solved... only time will tell.

Thanks, everyone, for your help! You guys are great.

 

You're welcome.

I have a funny story. I bought a 94 accord. The guy I got it from said every once in a while the temp would go up. Not into the red, but up a bit. He said he put a t-stat in it and the problem hasn't returned.

About a year after buying the car I noticed the temp rise a tad. I turned off the A/C and the temp wen't back down. When I got to my destination I checked the fans, they turned on.

Some time later one fan went bad. I replaced it with a practically new one I had laying around the shop. The problem was I couldn't use my existing fan blade and had to rob one with the OPPOSITE fan blade pitch from another fan.

So, being the guy I am I opened the fan connector, switched the terminals to get the fan to spin in the opposite direction attempting to compensate for the reversed fan blade pitch. Fan came on, job done.

Driving the car a few months later and the temp went up again. Stopped and checked the fans. They came on. BUT, as the fans shut off I realized...Continued.

 

.... I realized that THE FAN WAS SPINNING THE WRONG WAY!

The previous owner had the fan motor replaced. When whoever replaced the motor did the job they had to use a different blade ( backwards pitch ) but did not reverse the terminals!

The original problem of overheating he noticed was caused by a backward spinning fan! I was unaware of this, reversed the terminals when I replaced the fan blade. If when I had replaced the blade with the reversed version I had left the terminals alone the problem would have been fixed!

I laughed when I realized what had happened.

 

That's funny - so you reversed the previous reversal... Awsome...