Hello, I am a newbie here.

My 95 dohc neon is overheating due to boiling coolant. I replaced thermostat, radiator cap, and the waterpump is new. When its overheating, if I turn on the heat it blows cold air, not hot. And it spills coolant from the side of reservoir, right away. The fans still turning and working. I can still drive 10 miles before it overheats.

What could be wrong? Please help!

 

well by reding your post the only thing left in the cooling system that is not new is the radiator. might be time for a new rad.

 

Sounds like a blown head gasket to me. Try running the car with the cap off, it should stop bubbling after all the air is out. If it overheats and does not stop bubbling, you need to do the head gasket.

 

that should be fun!

 

If you haven't flushed all the air out of the system, it will still boil, even with a fresh rad cap. It usually takes me 3 tries of running with the cap off, topping off as needed when the thermostat opens and level drops, to get all the air out of the system.

If air is still getting in, you'll get the bubbling back. Tracking down the leak can be a pain, because all it takes is a pinhole. My last one was coming from the radiator, right where the core meets the top end bell. The metal tabs that clamp it on were rusting off and a tiny gap had developed. Finally replaced with an rust-free aluminum core radiator after going through 3 crappy copper ones in New England...

There is always the chance it's the head gasket, particularly if you have the original non-MLS style in there. MLS gaskets rarely develop leaks, but driving with air in the system for a while can do it,as can continuous overheating (warped head). Could also accelerate wear on the water pump (bearing cooled by the coolant, steam doesn't work so well...), but you should see coolant dripping out the weep hole if it was that bad.

So - get all the air out of the system first by runing with the cap off and topping off when level drops after the thermostat opens. Then check it again a few days later. If there's still air getting in, start checking the hose connections and around the radiator for leaks. Do a compression test to check the head gasket ($20 for the kit at a parts store).

Best of luck!

 

I'm also having cooling issues with my 96 sohc. I just got done replacing the head gasket and bleed the system and their are no more air bubbles but my radiator fans are not coming on and I'm not sure why. I checked the relays and fuses but nothing is wrong with them. Any suggestions?

chefneon

 

They aren't even coming on when you turn on the a/c? Try running power directly from the battery to the fan(s). How did you check the relay?

 

No, its not coming on even when the a/c is turned on. I'm going to try and connect a 12v source to it just to see tomorrow. As far as checking the relay, I ohmed it out to make sure that they have continuity. I'm trying my hardest not to go to the dealership because I know they will be charging me alot.

Thanks alot for your help.

chefneon

 

Ok, I finally had a chance to check if those fans worked with a direct connection to a 12volt source. Well, they worked just fine so I connected them back up to the car and tried it again by turning on the a/c and they still didn't come on. Again I checked the fuses and they are ok and I also switched out the relay but the fans still do not work. Anybody has any suggestions of what else could be the problem? If not then I'm going to have to go to the dealer which I don't really want to do.

chefneon

 

not sure if same basic setup as a genII but it is pcm controlled on genII which either means bad temp sensor or bad conductivity in control circuit. If you pull the Relay with Key On Engine Off you should have 12V on two leads at the relay. Check both for load carrying ability with a standard 12V test llight as well as for 12V with Multimeter. If that is OK then Check for Ground availabililty on control circuit (Hopefully your relay is marked ckt 30) with a multimeter when the fan should be on like AC on and should have no more than .3 Ohms.

Hope that helps.