I have searched for a very long time thru all of the threads on here and still cant figure out what to look for now. My car continues to overheat

The car is a 1995 camaro 6 spd. I just installed a 1997 long block because of a head gasket blowing in the old engine and locking it up.

I jumpered the 5 and 6 pin on the dlc and the fans turned on, so this tells me that the wiring and pcm works, correct?

I switched the relays in the engine bay, didnt fix it.

I bled all of the air out of the system with the 180 stat with the car programmed for a 180 stat. didnt help

I bled all of the air out of the system with no stat, helped a little but still overheats.

I replaced both coolant temp sensors, didnt help.

The fans will not tun on at all unless the 5 and 6 pin on the dlc is jumped.

I cant turn on the ac to see if they come on because it is not charged.

Please help, i have two days to get this figured out

 

The cooling problem is def the fans. I just hard wired the fans to a manual switch and it cooled normally. I tried to reset the pcm but that didnt seem to help. Im pretty sure that the wiring from the relays to the fans is ok. How else can i test if the PCM is capble of turning the fans on? I tried to disconnect the AIR pump fuse and relay and then wait for a ses light, but the light never appeared. In desperate need of help.

 

Just pulled the connection from the ect sensor on the waterpump ad started the car. The ses light came on along with both fans. Now i know that the pcm is capable of turning the fans on.

SO

The fans come one when:
Pins 5 and 6 are jumped,
The fans are directly hard wired to a voltage source,
The ses light comes on,

since the water pump measures temperatures by variable resistances (ohmometer), Would it matter if the wire hat connects to the sensor has a piece of insulation worn of, Not cut but just so that a small portion of the wiring is showing. Would it be possible for interference to occur or a false resistance reading which would cause the pcm to think it is actually a different temp?

 

If the PCM is getting a low temp from the sensor in the water pump, the fans won't come on by temperature.

 

Please do not "hard wire" the fans directly to a voltage source. Go through the relays.

About the bare wire showing, no that little splice is not causing the problem. The temp sensor in the pump is an ohm meter like you said, and the splice is not adding more or less resistance. If the wire is touching something like the pump housing then you might have a problem.

Turning the AC on also turns the fans on.

 

Would going from OBD1 engine to OBD2 engine have anything to do with this?

 

Have you had it scanned to see what temperature the PCM is reading from the sensor in the water pump housing? The low speed fans should come on at 226*F and the high speed at 235*F. There is no difference in the fan wiring between late 94/95 OBD-I and OBD-II.

 

Don't worry, im not hard wiring the fans as a permanent solution. I ony did that to verify why i had a cooling problem.

I cant turn the ac on because it is has no refrigerant in it because the lines were disconnected during the swap and i don't want to burn up the compressor.

The only difference between the 97 and the 95 long block was the knock sensor and the crank position sensor. The sensor hole has been plugged and the knock sensor taken care of.

The only thing i can come up with is the gauge showing a wrong temp or the water pump temp sensor relaying a wrong reading to the pcm, but that sensor is brand new.

Thanks for the replies so far. I don't have access to a scanner. Any more suggestions would be very appreciated!

Oh yeah, the pcm has been programed by a HPP3 for a 160 stat now

 

I just reprogrammed the comp for a 160 stat. The fans now come on when the gauge on the dash reads a little over 210 degrees. the car runs now but at an unusual 210+. I'm not sure why the fas are coming on so late. its almost as if the temp on the block is 40 degrees hotter than the temp at the water pump. Could this be and if so , what would cause this?

 

The sensor in the side of the head (one going to the gauge) might be wrong. The car running at 210+ is normal. These cars are not meant to run super cold. My car runs a little over the half mark, sometimes close to the 3/4. Like Injuneer said, the fans do not come on until 226, then 235. About the degrees being 40* different, I don't get what you're saying. If the temp is reading a little over 210, and the car runs 210+, then what is the actual temp?

 

You need a scanner to verify what the PCM is seeing as the temperature. That's the only way to know.

 

Before the head gasket blew in the old engine, my car never got above 180 degrees. I got the engine to stay around 210 but am still worried because the temp fluctuates with the fans. Is there a possibility that the hpp3 ****ted on me and is using the stock fan settings?

 

As everyone stated the best thing to do is to get it scanned...

Sensor in the side of the head is only for the temp guage. Waterpump sensor is for PCM.

 

The answer has been given to you several times.... have it scanned. Can't get any clearer than that.

And PLEASE don't test the language filter.

 

After pulling everything apart, cleaning it, and putting it back together.......the fans work?? It fixed itself somehow and the fans now keep the car cool. Thanks for the replies.

I didnt want to get it scanned because it was friday and the car would not of made it to any shop that had a scanner..thanks though