Hello,

I have a 1965 El Camino that is being restored. Engine turns on fine and after a couple of minutes, the radiator starts making thumping noises. It seems as if the coolant is being trapped inside the radiator and not flowing to the engine.

The top of the radiator has a hose connected to the top of the engine (Not original... V-Eight - 350?...I think) and I was told there may be a problem with the thermostat. Does this seem like this is the case?

How much might a new thermostat (Or related parts) cost and can I buy this anywhere?

If not, what might be the problem?

Notes:
New Coolant , Oil (and filter), gas, spark plugs, ignition coil.
Also, I am innexperienced with cars . :?

Just as a temporary thing try removing the thermostat and filling it.
A thermostat should cost you about 5 bucks and should come with a new gasket. Available at any parts house.
The thumping noise is steam from the engine. It sounds like you are not getting it completely filled and have air pockets.

you should be able to get rid of the air pockets by removing the radiator cap (when cold of course :) ) and starting the engine, you should see the coolant level rise and fall when you increase/decrease the throttle, add coolant while running to top off, give a few min to rise to operating temp , replace cap and you should get rid of the air

Hello again,

Thank you for your replies. I will try your suggesstions out tomorrow.

Before reading your replies, I opened the cap covering the thermostat and gue and old coolant leaked out. I did not realize the old coolant would be in that area. I cleaned out the gue. I have not yet tested if cleaning the thermostat solved the problem, but I probably should just replace the thermostat like you (464elky) suggest.

I would never have guessed air pockets would have been the cause. Thank you for your suggestion 'L K meano biker'. I will try this after replacing the thermostat.

Like I said before, I do not know much about working on cars. I did not even know what a distributor was two weeks ago. I really appreciate your advice. I will post another thread after I have tried these suggestions to let you know the outcome.

Thank you,

Bob

If as you say the engine is not orginal, my question would be "when was it replaced and with what?"
The main reason I would ask that is trying to determine if the water pump is a reverse rotation punp or if a standard punp was being driven with a serpentine belt arrangement.
Just for the information, in the mid 80's General Motors changed over from the multiply belt accessories to the single belt system and when they did it became necessary to spin the water pump the other direction----if there is a mismatch on these parts your water pump is trying to force water through the thermostat the wrong way.
I darn near burned up an engine---with the same symptoms you describe---before I figured out the new replacement waterpump I had just put on had been mislabeled and was indeed a standard water pump being used on a 88 pickup with the serpentine setup.....hope this helps some..........................Dan