Overheating---Airpockets?

[77BIGCHIEF]

I recently replaced the timing chain cover on my amc 360, after it go a hole the size of a dime in the old one and made my oil into a "milkshake". I am now experiencing overheating, especially when I shut the engine off, which I had not experienced before the timing chain cover replacement ( or when I rebuilt the motor before). Could there be an air pocket in the engine that is not getting coolant and causing the overheating? I ask this because I saw it happen to a "custom hot rod" on a TV show where it had a brand new crate motor and they did "something" to rid the block of the air. I have a newer radiator, water pump,hoses, NO thermostat... Has anyone experienced this or have a solution? Thanks, it's hard enough to keep a Jeep cool in the summer here in Arizona, let alone the winter?

[Elliott]

If a pocket is the problem you can burp it by turning your cockpit heat control wide open and warming the engine up at idle with the radiator cap off through a full warm up.

[77BIGCHIEF]

Thanks for the tip Elliott!

[Don S]

..
77BIGCHIEF;

... Here is a theory that a highly respected mechanic has about Removing the Thermostat...
he says NO! :eek:

... The flow configuration for the coolant is that the water pump pressurizes the block. The head distributes coolant though the cavities into the block. Block pressure must be consistent from front to rear to insure uniform coolant distribution and to reduce water pump cavitation.
Less pressure will results in less flow around the rear cylinders. When we boil this fact down it simply means the thermostat is a useful tool in maintaining the pressure. The block pressure should be slightly higher than the radiator pressure.

... The thermostats are beneficial to upright radiators with weak pressure caps. The restriction slowed the flow and kept the pressure in the radiator down. This prevents the cap from expelling water and causing the car to overheat. Most people wrongly assumed the car ran hot and expelled water. The cars actually expelled water and ran hot.

Did you reconnect the heater hoses? They carry hot coolant away from the rear of the engine.

Have a good one.. ;) Don S..

[g503]

yeah i would put in a thermostat and there are units that can purge air while putting in the correct anti freeze and water mix, some shop should have one that way it is flushed and the correct amount is in your truck

[77BIGCHIEF]

Yeah, I took itout to see if it was an obstruction rather than a bad thermostat. I just remembered that I also replaced the heater core at the time that I did the timing chain cover as I wasn't getting any heat, but I certainly do now!

[g503]

good to hear ,that makes another post for me,haha

[Jlamb]

The chances of an AMC motor getting an air pocket are slim to none. I am not saying it can't happen, I am just saying it is not likely. And opening the heater control valve will not work because these rigs have a door rather then a valve. The valve taps into the heater hose or core, and the door closes to prevent hot air comming into the cabin. So it does not matter if you had the heat to the full on position. I don't think you have air in the system.

[Elliott]

Originally posted by Jlamb3485:
The chances of an AMC motor getting an air pocket are slim to none. I am not saying it can't happen, I am just saying it is not likely. And opening the heater control valve will not work because these rigs have a door rather then a valve. The valve taps into the heater hose or core, and the door closes to prevent hot air comming into the cabin. So it does not matter if you had the heat to the full on position. I don't think you have air in the system.Yer right, now that I picture it that was my TR that had an actual valve.

[David Milne]

Chaps, I have the opposite problem !! It doesn't seem to really warm up. I have replaced the thermostat and the temperature sender unit, and it now reads a fraction of an inch above the top of the blue. A little heat, but not much out of the heater. Radiator feels hot to the touch at the top, but you could keep your hand on it just about. Air from the fan is warmish, but a lot cooler than I would get from my TJ. Any thoughts ? I guess my next step is to buy a thermometer and find out exactly what the temperature is..

[jeepsr4ever]

I would recheck your fluid level before you throw the air pocket card down

[77BIGCHIEF]

Fluid level is good (new coolant 50/50 mix), hoses are newer as is radiator, and yes I do have the fan shroud.

[jeepsr4ever]

timing good? fan clutch good?

[77BIGCHIEF]

No clutch on fan. Did my rig originally have one? 77 360 at

[Elliott]

Originally posted by 77BIGCHIEF:
No clutch on fan. Did my rig originally have one? 77 360 atThere's yer trouble, no clutch and now your blades are also too far from the radiator.

[77BIGCHIEF]

Thanks again Elliott! I will let you know what happens.

[Don S]

Originally posted by David Milne:
Chaps, I have the opposite problem !! but not much out of the heater. Radiator feels hot to the touch at the top, but you could keep your hand on it just about. I guess my next step is to and find out exactly what the temperature is....
David Milne:

... Have you felt both heater hoses after the system has been operating for a bit? Most heater cores have smaller passageways and some can get plugged up. It happened to mine. Pull off both hoses and flush in both directions with a garden hose. My V-8 flows from the back of the engine through the core then up to the front.

... Buying a good thermometer is a great idea. The reading in the tank will only be a couple of degrees less than the thermostat operates at. Mine shows 179 degrees and I know where the needle of the gauge points at that temperature.

Take care.. ;) .. and CUL.. Don S..

[David Milne]

Don S advised:

Pull off both (heater) hoses and flush in both directions with a garden hoseGood thought, will try that. Thanks !

[skunked]

A couple of points. No therostat will NOT help the engine. It will either make it run too hot or too cold. ANd 50/50 mix is probably too much. See what the bottle says and mix it in the proportions needed for your climate. Remember antifreeze has LESS cooling ability than water, the less you can run to provide the antifreeze effect and provide the proper anti-corrosive protectiona and proper water pump luberication the better off you are.

[David Milne]

Skunked quoth:
No therostat will NOT help the engine.Plus with no thermostat, you dont get the correct pressure..