overheating mystery to me

[tg1hq]

OK, here's the thing: 89 Formula is overheating. No fluids leaking. Radiator 4 months old. Thermostat 2 months old. Hoses are OK. Fans are coming on correctly. I'm thinking bad water pump?
I started it up with radiator cap off to see if coolant is flowing. Yes it is. With the radiator call on, the upper radiator hose is very firm like it's blocked up or something. Can it be that the thermostat is faulty and not opening? I don't think the coolant is flowing as it's supposed to.
Anyone have this problem?

[skibum1111]

Sounds like either a clogged radiator or a blockage in a hose somewhere or possibly a bad thermostat. Check your thermostat first, if it checks ok the pull the radiator and do a flow test on it, the bathtub works pretty good for that. If thats ok start looking at hoses for a restriction in one of them, it might be kinked or pinched somewhere. If you are getting coolant circulation then your waterpump is good,if it was bad there would be little or no circulation or a leak out of the weep hole.

[tg1hq]

Sweet. I'll have to wait for the weekend to check it all out. Thanks.

[tg1hq]

Could it be that there is air in the system somewhere? I'm not leaking coolant. Isn't there some sort of bleeding valve or something?

[tg1hq]

I figured it out. It was a bad cooling fan relay. My car has dual fans, and a while back one gave out due to its relay being fried. So, I had wired it to the other fan. Well, I guess I was drawing off of the good relay too much because it was a little brown inside.
Well, I found a $5 relay at the junk yard, got some wire connectors from Radio Shack and replaced it. Works just fine now. But, I still have to replace the other fried relay so I can correct the wiring back to the original factory set up.

[Rally Sport]

If I were you.. i'd buy a new relay just to be safe because buying stuff from the junkyard isnt the best thing to do. You'll be happy when you do buy new stuff instead of used when it doesnt go out on you like junkyard parts usually do.