First i apologize if this has been discussed to death. I couldn't quite find anything via search that quite fit the bill. Found a few posts with electric fans or missing parts that don't really apply to me. So I figured I would give it a fresh go...

I have an 82 Berlinetta, 305 4bbl. The car runs fine and temp is good around 200 when in motion, or during the winter months. Here outside temps in the summer often reach 100+.

So on these hot days the temp rises steadily at stop lights. longer intersections bring it to overheating temps according to the gauge. As soon as i get moving the temp falls right back down where it should be.

I replaced the water pump and i know its right, belts are tight and all the shrouds and air dams are in place, the radiator is good too.

The only thing different about it from stock configuration is the fan. We were having this problem and i replaced the water pump and radiator to try and solve it. Then I thought it was a low speed air flow problem so I removed the clutch from the fan and out a direct drive adapter on it thinking maybe the clutch was bad.

Still the problem persists. I am out of ideas other than maybe there's a better radiator or some trick that i just don't know.

Any suggestions?

 

I would install a wet gauge to rule out the stock gauge being bad and go from there.

 

Get with the times and yank that manual fan and install a electric fan. Solve your problems in a hurry.

 

I don't know if it's even possible, but could the fan be put on backwards so that it's blowing toward the Rad and not pulling through it like it needs to be? I know, pretty weird idea, but that's all I got right now...

 

i might try the electric fan route.. I know for sure its sucking air though the rad.. the amount of air that thing blows over the block when you rev it is ridiculous.

Ill have to try out the wet.. its just seems odd that it would appear to work while moving and then not when i stop. this things really got me beating my head against the wall.

 

Have you changed your thermostat? They do get old and wear out, I totally agree w/ the wet gage idea, before you go jumping in head first...

 

I'm in the same boat. Stays good while moving, but as soon as I stop, it starts climbing. If i'm on the hwy, the temp stays at about 200-210. I got electric fans and 1 stays on all the time, so its not the issue. I think my problem is with the carb, I got a holley 600fcm that I tuned it by turning it in then out about 1 turn. I checked pretty much everything that has to do with the cooling system. It could also be a head gasket, which I'll find out when I stop being lazy and do a compression test.

I'll let you know If I find the problem

 

i would upgrade your fan to eletric fan they work wonders

 

Much interested in your findings should you solve the issue. and to answer some questions,

Gasket should be ok.. haven't run a compress test but the engine only has maybe 20k miles on it. therm is good, that was one of the first things I replaced. It does need a new carb or at least a rebuild tho. It never occurred to me that the carb is going to have anything really to do with the cooling.

Just for my own education could one of you enlighten me as to how it ties in other than idle speed?

Thanks all

 

Check the thermostat, Was the waterpump rebuilt or new ?..Also take a temp gun and shoot the upper and lower hoses on the radiator..Verify that the temp your gauge reads is accurate..Sounds to me like your waterpump does not push enough water at idle..If that is the case try removing your thermostat altogether..Could also be the temp sensor is whacked out so verify first...