So, I am not 100% sure as to what might be causing this or if it is normal. My 70 olds 88 delta with the 455 2bl in it seems to be possibly running hot. Before I start it up I check the antifreeze level, and then after driving when i get home, it seems to be leaking antifreeze (through the overflow tube) onto the ground. After the car cools and I go back to it the level is low, down about a quart or so. I fill it up and do it all over again. when i bought the car it had sat a few years and there was no antifreeze in it (due to frost plug going bad). I had it in to my shop, and they replaced the frost plug and did a test on the cooling system, cleaned it out, flushed it out, and put new antifreeze in it. I asked them about the radiator and such (considering age and sitting) and he said everything checked out, it had good flow and such. I am just wondering if the thermostat went bad? or what could be the cause. You can smell antifreeze but it doesn't smell hot.

 

A common mistake (in a 'closed' system) is to top off the radiator to the top of the neck. This leaves no room for thermal expansion resulting in a small puke to give itself some room. After it 'pukes' from the overflow hose, you will notice the level (cold) will appear low (about 2" from the top of neck is about right). That's where you'll want to leave it. If the car is not running hot you will be fine as the hot coolant will expand to make up the difference.

 

Ok, good to know, I only have the dummy light and that doesn't come on ever when I am driving. Now I can rest assured everything is good. I just recently moved to SC and I am very excited to get the vehicle from MN to SC. This fall the season will slow down and I will be able to drive up there and trailer it back. Not sure if I want to drive it all the way down, though what a great road trip with the top down.....we will see... Thanks for the reply!

 

There you have it! A system with no overflow tank should never be filled full. There should have been a label near the filler neck saying to to leave it about 2" below the neck, but after 40 years, they go missing.

Hilton Head SC?
That is where I bought my 72 vert and drove her home to TX 3 years ago! Neat place for sure...

 

Good information.

 

My '57 was loosing fluid in a simlar fashion and I changed the rad cap in June and have not lost a drop in two months!!!

 

good to see another 70 delta convertible on here not many around anymore

 

My 75 Delta Vert was over heating about a month ago. I replaced the thermostat with a 195. Not sure what was in it before. Now it runs anywhere between 195-210. Is it ok for the car to run that hot for long trips (more than 50 miles)? The water pump works because I see the coolant move in the radiator neck when I start it cold. I also replaced the fan clutch because it was a cheap fix and it wasn't difficult to replace. I'm wondering whether I should replace the water pump too.

 

195-210 is not unreasonable at ambient temps of 90*+.
The temp light comes on between 250-260*, so it is well below the factory's view of 'overheating'...

 

Thanks for the info. That's good to know. When it was running in the 250s I knew I had to replace the thermostat. I'm just not ready to change the water pump yet due to another project that's more critical.

 

If your car is not overheating and your water pump bearing is not loose or making any noises(sign of the bearing going bad) you really do not need to replace it.

 

The new thermostat and the fan clutch did the trick. She doesn't go over 210 now.