I have read tons of info on this replacement and still can't find this dam sensor. My issue is the car runs great have to have the a/c on for the cooling fans to operate. If ac doesn't turn on the car overheats. I got the sensor in my hand I read online it's either on the radiator itself or on the block. Can someone help me so I can enjoy this car lol.

1992 pontiac firebird 5.0

 

It's on the engine head passenger side close to the engine oil dipstick. Do a search lots of info on posts and threads.
Best of luck!

 

Thanks man I'm still trying to look for it... is it replaceable under hood? Or have to be raised? Thanks

 

Replaceable under hood but you will get a coolant splash!

 

It's easier (to me) to jack it up or drive it up on ramps to change from underneath. And yes you will have some coolant come out. Make sure to top off the radiator after you do this.

 

Ah trying my best to get my fat hand to feel even the sensor under the hood I might just have to ramp it :/

 

You can see in the picture here where the switch is. It is that brass piece sticking out behind my wires. With stock exhaust manifolds, you probably can't see it easily from above or at all.

 

Nope not at all I'm taking a pic of engine bay when I get home
... no jokes it needs work lmao want to get it running rite before dressing it up.

 

Haha yeah, I just finished making mine look nice. It looked miserable before because I had a huge intake manifold leak that covered the entire engine in crusty goopy coolant. That, and old oil stains made the entire thing brown.

I decided to pull my engine and do some mods, then make it look all nice and fancy while I was in there.


Like others were saying, coolant will come out of it when you take it off, so since you most likely will have to be under the car when pulling it, make sure to wear safety glasses and such! Maybe you can get lucky and loosen it from under, then go above and pull it out, but you'll have to be prepared to have the coolant start spilling out when you fumble to put the new one in.

 

Yea of course it's nice and dark out so gonna have to wait till after work tomorrow... I wanna put headers on it any suggestions? I saw them ranging from 100 to 1500 on ebay lol

 

Well I did a bit of research on what to get before I bought mine.

There are a few good brands out there for sure but there are two that I would recommend.

I purchased the Hooker 2055 headers. They come with the y-pipe which, if you are going to replace the exhaust manifolds, you REALLY want to replace the y-pipe too because the stock on is quite restrictive and small.

If you plan on keeping the car for a long time, and want to make the engine look nice, I HIGHLY recommend getting whatever headers you purchase ceramic coated. The benefits of ceramic coating are:
- Helps keep engine bay heat down a lot
- Helps keep heat IN the headers for proper operation of your O2 sensor
- Keeps the headers from rusting! (MAJOR benefit here, no coated headers can fall apart in under 5 years)

I bought the non ceramic coated hooker 2055 headers/y-pipe combo, and had just the headers coated (because I wanted to cut off the stupid air tube thing before they were coated).

The other header y-pipe combo that I hear very good things about is from Dyno Don. I believe he is still making them he was very active on these forums. I didn't see his headers until after I purchased mine. I would have probably went with his instead, but I'm quite happy with mine.

Another thing, I would plan on trying to go with 3" exhaust all the way eventually with the motor. So whatever headers-pipe you decide to get, try and have the y-pipe tail end be 3".


One thing is, when installing headers, you will need to unbolt the passenger side motor mount and jack the motor up to get that side in. It's not too bad, but I didn't know that at first and became somewhat frustrated when trying to figure out how to get that side in.

Also, changing plugs with headers can be an ordeal if you don't have the right wrench set. I would HIGHLY recommend getting a 5/8ths offset wrench for the plugs. It makes changing them a breeze:

http://www.sears.com/craftsman-profe...p-00944318000P

I found, after messing with changing plugs twice before, that my neighbor gave me some old tools he had and had a 5/8ths offset wrench in the bunch. It's a lifesaver when you have headers.

Edit:

Here is a link where you get can Dyno Don's headers and Y-pipe:

http://www.top-downsolutions.com/pow...hout-air-tubes
http://www.top-downsolutions.com/pow...no-don-headers

You can also get the headers with the air tubes from him too if you plan on keeping your smog pump. Overall they aren't that cheap, but I think they are a pretty good value for quality.

 

Ok so I changed the switch for the rad fan and nothing so checked to see if it would still come on with ac and nothing no then changed the relay and only comes on with ac on again now what the he'll could be the issue now

 

Hmm okay so you are saying you changed the switch, and the fan wouldn't come on at all, even with the AC on?

Then you changed the relay for the fan, and now it's working like before, only with the AC on?


The stock temperature for the radiator fan to come on with the AC OFF is very hot in my opinion. I don't know the exact number, but I think it's around like 225 degrees.

It may be that the switch is working, and the engine just hasn't reached that temperature yet.

Something to notice: The stock temperature gauges on these cars are very often quite inaccurate. Chances are that, if you coolant is not boiling over into your reservoir, you actually are not overheating. You gauge could be reading off.

One thing I would check though is the wiring to the fan switch. The way the coolant switch works (the one you just replaced) is that when the engine gets hot enough (the switch itself), it acts as a ground for the cooling fan. To test if the wiring to the switch is good, you can unplug the switch, and ground the end with the engine in the run position by holding it against a clean piece of metal on the frame/exhaust etc. (doesn't have to be running, just accessories on)

If the fan does not come on when that wire is grounded (and the power is on to the car), then you may have a break somewhere along the way!