The impossible to solve overheating problem

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Does the timing not affect the O2 in the exhaust at all? I.e rich/lean?
Anyway, I adjusted the advance and retard to pretty extreme in either direction just to see that my timing mark wasnt off or something but it made no difference so I set the timing to where the engine runs best. The carb is adjusted correctly with respect to rich lean.
The car came with an engine driven fan without a shrowd which I have tried since this problem started again yes. Thing is both set ups have worked old and new.

Maybe, but saying the timing is rich or lean is using incorrect terminology and will lead to even further confusion. The carburetor is what controls rich and lean, not the distributor, so lets get that right so we won't be struggling to understand you and can help you a little easier.
 
How much vacuum does the engine make during idling in neutral and in drive?

I have a fairly similar 360ci engine, powersteering, Doug's headers, only with a XE256 cam and 11.3:1cr.
My car has a fan shroud which really helps.
With the 160F thermostat it stays around 150F pretty much all the time, unless I get into heavier traffic, where it will climb to 160-170, 180 max. As soon I as hit open road it drops back to 150-160F.

What's the diameter size of the crank and waterpump pully? Can you locate and try a smaller waterpump pully perhaps?
I know the waterpump pully on my setup is roughly 14-15cm in diameter.

I cant remember exactly but the vacuum seems healthy, how so? Not sure about the size of the pulley either, have no access to the car, right now but about 15cm. The car has run cool with this pulley in the past.
 
Everything I read here and taking into account all the symptoms would make me VERY suspicious of the water pump.
I have even seen some that the impeller came loose from the shaft.
If this is the case then coolant isn't circulating, and would cause an overheat under any circumstances, and with any radiator or any of the best parts out there.

That's a really good thought. Well worth investigating.
 
What are you using for a gauge? Are you really overheating? I recently lost the ground on my Autometer temp gauge. It would start cold and climb to 250 in less than 2 minutes. I repaired the ground and gauge dropped back to 180. No matter how inadequate your cooling system is, it should take 5 minutes or more to get to overheat condition. Verify your temp gauge is accurate before you chase other issues.

Yup, did that with an IR gun..
 
That's a really good thought. Well worth investigating.

Let me add that even if a person pulls the radiator cap and it looks like the coolant is circulating ok, that doesn't mean it is flowing like it should at higher RPM's.
That pump should be removed and the impeller to shaft integrity verified before I would be satisfied that it isn't the problem in this case.
 
Everything I read here and taking into account all the symptoms would make me VERY suspicious of the water pump.
I have even seen some that the impeller came loose from the shaft.
If this is the case then coolant isn't circulating, and would cause an overheat under any circumstances, and with any radiator or any of the best parts out there.

Note that a gasket leak or a crack somewhere would cause coolant to be pushed out from building pressure just before it overheated.
If it doesn't puke coolant it probably not a compression leak.
(A radiator pressure tester will confirm this one way or the other, without needing to send a coolant sample away)

I really wish that was the case but the impeller is not loose from the shaft at all, the water pump looked good. Nice blades, a little surface rust.
I havent really let the engine got hot enough to puke coolant, just once and it did puke from the overflow tank.
You can check for leaks by pressurizing the coolant system and seeing if pressure drops?
 
Low vacuum would mean a (mild) engine is not running optimal, or sometimes even struggling to stay running.
Could be from a lousy mixture, piston ring seal, vacuum leaks, ignition timing or cam timing.

Some peeps think 12-15" vacuum is healthy. I think around 20" is healthy for a mild engine.
With your cam I would expect it to be around 18-19".

But if all fails I will offer myself and take the car of your hands for €200,-.... This will save you from spending money on long term storage... :D

Have you ruled out the single (?) v-belt is possibly silently slipping on the crank pulley when running?
Do you notice any jerking in the steeringwheel maybe while driving/steering?
Is the power steeringpump rotating 'fairly' freely?
 
You may as well put that car on blocks for long term storage. You keep shooting down every idea.......yet YOU HAVE SOMETHING WRONG!!!!!!

YOU have missed something here! YOU are going to have to double back over yourself and check everything again if you expect to find the problem! Did you check the impeller to see if it's not slipping on the shaft? I just bet not. Whoever does? Fact is YOU MISSED SOMETHING!

It's no big deal, but to keep shooting down idea after idea because "YOU KNOW" that's not the problem is pretty ignorant, since you don't know WHAT the problem is!!!!!!!!!!!!!

Not trying to be an *** here, but "I" would damn sure not resort to long term storage simply because I was too hard headed to recheck myself.
 
I really wish that was the case but the impeller is not loose from the shaft at all, the water pump looked good. Nice blades, a little surface rust.
I havent really let the engine got hot enough to puke coolant, just once and it did puke from the overflow tank.
You can check for leaks by pressurizing the coolant system and seeing if pressure drops?

I do it by getting say 15lbs of pressure in the system and revving the motor to see if it increases.
If it has a leak it will climb more with each rev until it starts pushing coolant out.
 
Low vacuum would mean a (mild) engine is not running optimal, or sometimes even struggling to stay running.
Could be from a lousy mixture, piston ring seal, vacuum leaks, ignition timing or cam timing.

Some peeps think 12-15" vacuum is healthy. I think around 20" is healthy for a mild engine.
With your cam I would expect it to be around 18-19".

But if all fails I will offer myself and take the car of your hands for €200,-.... This will save you from spending money on long term storage... :D

Have you ruled out the single (?) v-belt is possibly silently slipping on the crank pulley when running?
Is the power steeringpump rotating 'fairly' freely?

Haha seems like a fair deal :D
Thats a good point I actually have changed that v-belt and it is perfect for the crank and power steering now but a bit too big for the water pump... Can it really slip that much? Is the water pump that hard to pull..?
 
I would consider the water pump a cheap test. Replace it. They corrode and clearance inside the housing increases between impeller and the casting.
Bypass fitting correct size?
How is the flow at heater core?
Heater fan on high, heat on hot. engine at operating temp, both heater hoses should be almost the same temperature.

I had a heater core problem and clamped hose down.it created an overheating condition. Food for thought.
 
You may as well put that car on blocks for long term storage. You keep shooting down every idea.......yet YOU HAVE SOMETHING WRONG!!!!!!

YOU have missed something here! YOU are going to have to double back over yourself and check everything again if you expect to find the problem! Did you check the impeller to see if it's not slipping on the shaft? I just bet not. Whoever does? Fact is YOU MISSED SOMETHING!

It's no big deal, but to keep shooting down idea after idea because "YOU KNOW" that's not the problem is pretty ignorant, since you don't know WHAT the problem is!!!!!!!!!!!!!

Not trying to be an *** here, but "I" would damn sure not resort to long term storage simply because I was too hard headed to recheck myself.

Yeah your kinda right I am shooting down ideas. But I checked the water pump shaft-impeller and its not slipping... Im just trying to find new therories that I havent checked. Like what BigBlockmopar said, that actually could be the reason for this overheating!

Probably only people that have had it happen, and spent a lot of time pulling their hair out.
OH, like this one.:D

Its a good point because its something that seems so far fetched so nobody would check it, and it would solve everything. But I have checked it.
 
I have witnessed a slipping impeller, one broken one,and one that was too far away from casting to be efficient.
Slipping belt? No brainer. It must not slip.
 
The waterpump actually takes the least power to turn.
While flinging around the coolant does pose some load on the crank/v-belt at higher speeds, it's not much compared to what the PS-pump or alternator (when charging) do.
 
I would consider the water pump a cheap test. Replace it. They corrode and clearance inside the housing increases between impeller and the casting.
Bypass fitting correct size?
How is the flow at heater core?
Heater fan on high, heat on hot. engine at operating temp, both heater hoses should be almost the same temperature.

I had a heater core problem and clamped hose down.it created an overheating condition. Food for thought.

What is the bypass fitting? I actually have no idea how the heater core flow is. Could be clogged for all I know, you mean that the heater core should take some of the heat from the engine?
 
Any chance you have installed a Marine or Magnum type waterpump?
Magnum engines use a serpentine belt and run the opposite way of a LA waterpump.
The waterflow is still the same in the engine, but the (Magnum) impeller might be inefficient with your v-belt rotation/setup and hardly pump any coolant around now.
 
Any chance you have installed a Marine or Magnum type waterpump?
Magnum engines use a serpentine belt and run the opposite way of a LA waterpump.
The waterflow is still the same in the engine, but the (Magnum) impeller might be inefficient with your v-belt rotation/setup and hardly pump any coolant around now.

Havent changed the water pump at any point, did compare the impeller blades to an LA water pump online and the blades were the right direction, provided that picture online was accurate.

But like you said, the new V-belt does not have a great contact patch to the water pump.. It seems doubtful that it would slip but it is definitely a possibility, that is one thing that was changed right before this overheating problem.
 
Bypass hose is right below upper rad hose/ thermostat housing.
If heater core isnt flowing, its a big issue,a hose to bypass it is fine but it should never be blocked or restricted.
 
Bypass hose is right below upper rad hose/ thermostat housing.
If heater core isnt flowing, its a big issue,a hose to bypass it is fine but it should never be blocked or restricted.

Great, I will check that the heater core is flowing and bypass it if necessary.
So the bypass fitting is the one below? You asked if it was the correct size? I have never changed it but I dont know if it is original. Can it be too small and restrict flow or?

large_1657_SB-bypass-fitting1.jpg
 
Unplug the fan. Disconnect the upper hose at the radiator. Prop the open end higher than the rest of the system. Take the radiator cap off. Start the car. Let it warm up to thermostat opening. Run garden hose into radiator at a reasonabe flow so as not to make a huge mess. Water pump should flow water out the top hose at a rate in relation to engine temp. As it warms up more should pump out. All sorts of things can be observed. If cold water can't get through fast enough, radiator may be plugged. If engine remains at a proper temp through different rpms maybe radiator isn't cooling well enough. I would triple check the thermostat.
 
You say you have tried it with and without a thermostat. Have you tried a NEW thermostat ???
A relatively cheap and easy way to start if you haven't done so.
Yote
 
one thing to check would be ign timing just because you turned the dist doesn't mean the timing is advancing the weights could be rusted and not moving, is yours bored .060 over because mine would heat up really fast in the winter but in a truck with a large radiator it would run 200 in summer with a 160 stat but run 210 when towing and that was with everything stock and new radiator also had problems milling the heads that low all the cylinders cracked between the spark plugs and intake seats.
 
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