kamasutra8769

ok , i have a 94 z28 LT1 with 141,000 miles. car runs strong. When i bought the car the temp gauge didnt work. i purchased a new sensor to find out that the orginal one was just unplugged. I plugged it in and it never got over the 1/4 mark. What ever. I drove it 1200 miles in one day from ohio to florida(no problems with anything except heat not working. had to undo the hoses to the heater core and flush it and the heat never blew warmer.). My exhaust manifold gasket on the passenger side blew out. So i tore it down and replaced it. while doing so the air injection tube broke off. so i found another one and replaced that. about 2 days after doing that i was driving down the road and realized my gauge was all the way in the red.its never went above 1/4 mark and all of a sudden its all the way to the top. wtf. coolent was coming out of the heater core hose(clamp was loose) dont know if that had anything to do with it. I replaced the thermostat. still nothing. then i noticed my fan not coming on.so i bought new temp switch and temp sensor. then come to realize the fan wasnt coming on till i was in the red. took it to a shop and they said it wasnt over heating that the gauge was reading incurrectly . they sold me a resistor to splice in to the temp sensor to the gauge. today i raced someone and after coolent was gushing out of my over flow. waited for it to cool down and took it home. took radiator cap off and the seal was destroyed. so i bought a new cap and put it on. just so you know that car runs great. no loss of power or hesitation at all at anytime. please give me some helpful hints here. (there is no white smoke coming out of my exhaust. there is no coolent in my oil. there is a tad of oil in my coolent but was told its getting in threw the waterpump(something with the timing soming seal or what ever.)



{94 Z28 Camaro Cold Air Intake, Flow Master Exhaust}

my1994z28

Ater you replace the thermostat,you have to bleed the air out of the coolant system..Shoebox has a write up on how to it.

Injuneer

If the cap was bad and wasn't holding pressure, the coolant boiling point was lowered to the point where you get the results you saw.

I'd straighten out the gauge problem - there is no reason to splice a resistor into the circuit. Test the sensors using Shoebox's guide:

http://shbox.com/1/4th_gen_tech2.html#ect

You mention replacing the "temperature switch"..... what exactly did you replace? There is no switch. The sensor in the water pump tells the PCM what the coolant temp is, and the PCM turns the fans on an off according to the programming. Stock programming turns on the first fan (or low speeds, depending when in the model year 94 was built) at 226*F, and the second fan (or high speed) at 235*F. If your gauge was showing in the red, its possible the loss of cooling system pressure allowed boiling in the head, resulting in the temperature at the head sensor being somewhat higher than at the water pump.

Check your sensors for accuracy, get rid of the resistor (make sure you have the correct sensor - the 2-wire sensor in the water pump functions at 5V, the 1-wire sensor in the head functions at 12V), replace the cap with the correct 18psi cap, and be sure all the air is bled out fo the system, and see how it works.

kamasutra8769

I have used the bleed ports. ive got all the air out of the system. The temp switch is what they consider it at the auto parts store. temp sensor is the one they consider the one on the block that goes to the gauge. We put a temp gun on all diff parts of the motors and hoses and they were reading fine but the gauge was incorrect. im just not too sure if its completely false right now. Makes me feel like a retard cause i have been working on cars for sometime now and by no means and expert, but i have never had so much trouble figuring out the cooling system on a car. Yea i replaced the cap with the correct one. Coolent has never came out of the over flow before today. I aslo havent been as hard on the car as i was today, plus it was roughly 95 degrees today. I didnt have any over flow after the car cooled down, even before replacing the cap. I did notice a diff smell in the coolent. almost a burnt smell(prolly from it getting so hot). Im still alittle new with the engine. Ive delt with other chevy small blocks before but not in this particular engine.

Guest47904

You need to get the gauge reading correct as was already suggested and also use a hydrocarbon test kit on the coolant. Get it at any auto parts store.

shoebox

Whoever told you oil was getting into coolant from the water pump or some sort of seal there has no idea of what they are talking about. The pump touches no oil. If you have an oil cooler, cross-contamination could be a possibility. You might want to pressure test the system.

kamasutra8769

I have checked all of the stuff you wonderful people have listed for me. Next person that is smarter than my friend please take a shot!

Injuneer

Do I detect a hint of sarcasm.



Good luck.

94Z28LS1toLT1

hey buddy I have gotten great advice and help from Injuneer and Shoebox and being sarcastic like that is being disrespectful so please show some appreciation

kamasutra8769

just having alittle fun. its been stressful lately. especially since since my car has been over heating. on the positive side yesterday i blew a 00 gt mustang away by about 7 car lengths. and he had more mods done than i did. i got his number he wants to go again. ill get a video of it for you guys once i get my car straighten out. didnt mean to up set you guys.

94Z28LS1toLT1

oh ok no worries i understand i have had alot of issues with the overheating before now i have learned alot from this website. good luck