I have a 98 Z28. The other day I went to the mall and when I got out I noticed my car was making a sound like a bird chirpping. Didn't notice anything so I went in. When I came out alot of coolant was under my car. Went to a parts store to get coolant to top off. Ran fine rest of the night. Next day I drove around awhile and when I got home and raised the hood I heard the same sound. Waited a minute and coolant started coming out of the neck where you fill with coolant. Been watching past few days and have noticed my fans are not coming on. Can get over 210 and still no fans. Even running A/C the fans do not work. Doubt it would be both fans going out at the sametime. Could it be a relay? Or maybe thermostat? Or something else? At what temp should the fans kick on?

Thanks

 

I think the fans have a different sensor for the temp of the coolant passing through the motor than the one at the thermostat. My understanding is that coolant must be passing over the sensor, not just the temp internally in order for it to tell the fan to engage but my understanding also is that one fan will come on automatically when the air conditioner is turned on. I am not sure what temp the fans are suppose to be energized. The fans on our 96 have never come on but the temp stays at or below the 1/2 mark on the guage. You can use a fused wire and attach the fans to a battery to determine if the fan motors are working. By the way, was your radiator leaking at the neck caused by the cap or a bad neck where the cap screws on? I am leaking around that area as well. Have replaced the cap with a new one but still find coolant around the top of it and have to keep adding. Guess I am going to have to replace rad.

 

i just got my camaro back from the mechanic with similar problem. went on a long trip to go camping, car started overheating, coolant spitting out of overflow tube. filled with coolant got it to campsite and let it sit for the rest of trip. got home ok, but then the next day if i let it sit in idle for about 45 seconds it got all the way up to max temp. first mechanic replace thermostat, but it still overheated. found out one of the relays to turn the fan on wasnt working, so replaced all 3 of them. runs fine now, but labor got kinda pricey (that and got door fixed while she was already in the shop).

 

the fans should come on when the air conditioning is on. if not u have a problem. yes it could be a relay or the coolant temp sensor, or the fan wireing or the fans or the sensor wires. not the temp gage sensor. my coolant temo sensor is on the front of the water pump. ls could be different. duck check to see if the top of the neck has any burrs and or grooves on it that would let somthing get by. not sure of the ls on, off temp for the fans mine come on about 200 and off 180 but thats how its been programed. i think the ls comes on at a higher temp. like 210 or 220. pete knows maybe he will come back for u on it. buy the way have u had it scanned for trouble codes?

 

I replaced a fan relay and seems to have fixed the problem. Two relays had the same # and one was different #. I replaced the different # one so I guess I picked the right one.

 

i had almost that exact same problem. my radiator had a crack in the plastic part and it was leaking. i filled it up with coolant but it became air locked so it spewed right back out. plus the wonderful person that had it before me completely removed the thermostat. $520 later i got it fixed just only after 2 months of owning the car.

 

the different one is for your abs. or should be not sure on the 98. mine has 6 relays. all same except abs one.

 

Hey I've had a similar problem. First my fan would not turn on, and my car would overheat to the MAX. One day my fan just turned on again so I thought it was a faulty thermostat. During this time I still drove the car because it wasn't overheating, until one day it was up to the max again and NOTHING would cool it down. It took about 2 hours for the car to go down to half on the gauge. So the next day I changed the thermostat and it was still overheating. Now I'm thinking it's a broken head gasket, so I'm getting that fixed. I'll let you know if that works.

 

That was not the problem. The one I replaced was a fan relay. It has 5 pins. The other two have 4 pins. Checked all fuses under hood and they were good. Guess I'll try the coolant temp sensor next. If all else fells I will run a manual switch to fans.

 

yah i noticed that u have a 98 after i posted. so its still doing it? dang. make sure u change the right temp gage. theres two of em on mine. one for the igintion system and one for the temp gage.