Biggs_Drums

1995 LX coupe...it's the F22B2 I think. The non-vtec. So yeah my temp gauge is going up and down...I remember it usually ran between 1/3 and 1/2 but never above 1/2, and it never changed noticeably. Now I will see it climbing and falling over and over within minutes. Can't be normal...right?

Now it runs anywhere between 1/3 and as high as 3/4. It's kinda freaking me out when it gets high like that...brings back bad overheating memories...and I hate driving my car when it's hot like that it can't be good for it. But it never gets any closer to the red than 3/4.

I replaced the thermostat and radiator all within the past 6 months, so those are pretty much out of the equation. Coolant levels are normal. Coolant is still clean, I use the regular green kind, rather than the purple Honda stuff. I'm not worried about that. I also did the throttle body coolant bypass mod a little bit ago, then switched it back to the normal setup because I didn't like the car idling funny at startup. I think before I did the mod is when this problem started...It certainly ran cooler with the mod but it still went up and down a little. Now its a tiny bit hotter and it worries me.

I noticed that when I'm slowly/casually accelerating it heats up, but if I kinda get on it and accelerate quickly it will actually cool it back down pretty fast. I am thinking it could be a fan problem, but I really don't know how to test the fans. The passenger side fan almost always turns on immediately after I shut my car off to cool it down. But I'm not sure if it comes on while I'm driving. Both fans turn on when I turn the A/C on. So the motors are good...maybe it's one of the ECT switches or possibly a sensor?

I have a voltometer but I don't know much about how to use it.

Thanks for any help,
Ethan

Biggs_Drums

Ok so I just got back from getting some groceries and I pulled over into a parking lot when it was heating up, cuz I was in no rush. I let it idle for a couple minutes in park, no change it stayed at about 2/3.

I gave it some gas held it at about 1900 rpm still in park and it started to go down pretty quickly. Then I let off the gas when it got to about 1/2 and the temp stopped dropping and stayed at about 1/2 while it idled. I gassed it up again to about 2000 rpm and held it for maybe 20 seconds tops and the temp smoothly dropped to the normal level i guess (between 1/3 and 1/2)

I don't know what it is. I keep thinking its a fan, but I just don't know how to test the switches or sensors.

statik215

You might have a air bubble in your coolant system. Bleed the air out. Take off the radiator cap and insert a funnel, start the car, let it heat up then keep adding 50/50 in the funnel until it stops bubbling. If that doesn't work then try changing your Temperature sensor.

YeuEmMaiMai

1. replace your t-stat and then properly refill and bleed the system

Biggs_Drums

I'll try to get any of the air bubbles out again...but I already opened the bleeder valve and coolant came out in a stream with no bubbles. I thought that meant it was bled? Anyhow I'm going to try your idea statik hopefully that will work. Just got done driving though I need to let it cool off now.

I doubt it's the thermostat because it is only like 6 months old...I know it is possible but it's really unlikely that it's bad already. I'll wait and try any other ideas before I replace it again.

Fireman.142

I think that the next step if you are still having problems after that is to do a compression test. This is exactly what happened to me when the head gasket went bad with the same car as you. just a thought.

statik215

Yeah I had the same problem. It ended up being my head gasket. I say check all of thoses minor things first because they are less costly. If none of those will fix your problem then its your head gasket.

Biggs_Drums

Awh ****. Well...I let the car run and squeezed out as many air pockets i could outta the top radiator hose. That didn't fix it.

There's no oil leaks though. Could it still be the head gasket?

NiChRiS

bump