I know this topic has been talked to death, and I've read through the back catalog of threads. Assuming the worst here on my 390, and hoping I have missed something. It's a 63 Galaxie with a tired, worn out C6ME 390. The motor is junk - but it's been a solid runner for years. Right now it has a big, newish Griffin radiator, and a many-blade mechanical flex fan (no fan clutch). For good measure I just swapped the (nice, newish Summit high flow) water pump for a cheapie Autozone reman pump. I have tried a 160 and 195 thermostat. I have tried electric pusher and puller fan configurations too. I have checked timing, and it's in spec - no pinging or power issues either, and no change in symptoms adjusting timing up or down. I have tried different blends of water and coolant, and no change either. I also just had the (basically new) Griffin boiled out, no change. None of what I have tried or changed has materially changed my symptoms in any way. It runs hot in traffic. Temp climbs, thermostat opens, hoses heat normally. Gradually, the temp just keeps climbing. It's not abrupt, but it is steady. Running the heater (which blows super hot) doesn't change it either. On the highway it's just fine, temp is steady and does not climb. If I get it hot in traffic and can get clear, the temp drops - but much more slowly than it used to. I can drive all day on the highway, but 10 minutes idling in traffic kills it. For many years, normal temp was about 1/3rd of the gauge. Now normal is 2/3rds, which I also don't understand. I am in GA, and ambient temps are 80s, which I've driven the car in for years with no trouble. I have stuck a thermometer in the rad and confirm the gauge is right - it climbs up past 225 and that's 85 percent on my gauge, roughly. A bit higher, and the car starts stumbling and running poorly. So - what am I missing? - I have no way to check for exhaust gas in coolant, and that's possible. This motor is a junkyard dog. - I have heard bubbles are an issue, but the thermostat is opening and closing fine, with obvious water movement and hose heating - so I don't think that's it - I have heard block sludge and rusty water passages are possible, but having drained (not flushed) a few times, the coolant comes out clean and not funky. Not sure that decides anything either way. So, what am I missing here? Thank you!
Do a gas check of the radiator water to determine of you might have a blown/leaking head gasket. Most radiator shops will do it.
Check the timing. It might have the nylon timing gear and it's eaten up allowing the timing to be way off. Common on FE's. Movin/on
Overheating Rule Of Thumb. Runs hot at low speed - not enough fan. Runs hot at highway speed - not enough radiator. If it were me I'd junk the flex fan and replace it with a steel engine driven fan and install a fan shroud. Gary
Fan shroud, 160 thermostat, aluminum radiator with at least 400 square inches of open surface on each size, and a decent metal fan. A smaller air intake will reduce heat trapped on the intake manifold, and an aluminum intake manifold will reduce heat even more. Did all of the above on my Thunderbird, dropped my 390 from about 3/4 gauge to just over 1/4. Made most those changes in a parking lot after I somehow managed to trash my radiator during The Great Race from overheating while in Michigan a few weeks back. Beyond that, I would check your cap and make sure it holds pressure
Just for grins I'd remove the two threaded pipe fittings on either side of the block, down low near the pan line. The block passages are often blocked full of scale and sediment.
Have you tried flushing out the engine? if not it can't hurt. The basic steps to flush a car engine block are: Remove the lower radiator hose and catch the draining coolant in a bucket. Remove the top radiator hose and flush the system out with a normal hose. Continue until the water runs clear out of the bottom of the engine. Refill with coolant and reattach the radiator hoses. Show us a photo of the fan. HRP
when cold, remove rad cap. start engine wait until it gets warm and thermostat is open. look in rad for water movement, if none to very little detected raise engine speed 100-200 rpm, if water movement is detected replace water pump pulley with a smaller one and your problems will be over. If you have one of those short water hoses from the intake manifold to the water pump, install a plug in it with approximately a 1/8" hole. Fords are known to bypass to much water without it going thru the rad.. good luck.
The plug with orifice in the bypass greatly helps . If not much flow is noticed , look at pump impeller also . For some strange reason I have found 3 rusted away impellers recently , causing major over heat issues .
I would have mentioned the pump impeller but just made an assumption it's good. On the YBlocksforever page this has been discussed many times, our family owned these engines and never had the overheating problems we have today. I am guessing that today's fuel does have something to do with it but not being in the business of fuel cannot prove or want to prove it. I do add Sta-Bil with every tank of fuel and personally don't give a s--t who says I'm wasting $$$.
Wow these are great replies. I wished I had received them when I posted last week about a friend's '63 Galaxie overheating!
I agree with. I've had this cure a hot FE ('64 Ford) years ago. Check the water pump bypass hose to make sure it isn't kinked.
Old FE's had metal head gaskets. With age, the part covering the big passage at the front of the engine will rust through, allowing coolant to flow through just the front of the block, creating heating problems.
I'm hearing nothing about "coolant" . you said you tried different combos . From my experience there is no better summer coolent than straight distilled water and a bottle of Red Line Water Wetter. Nothing cools better than water ! Anti freeze is exactally that !.... It prevents freezing but does nothing to prevent overheating on a hot summer day. throw that 50/50 green shit away for the summer and don't forget to change back in the winter if you live in freezing temps. the usual overlooked cause is a cap that will not hold pressure. I went thru this and with a fancy new cap that had a magnesium an ode on a wire to prevent electrolysis in my aluminum heads. The fuckin temp would shoot up to 240 like a rack needle then back to 170 . It drive me crazy till a Old mechanic friend suggested the cap. of course I said no way possible it's new. Well Old Stan was right !! I changed the cap and problem solved but myself and all my California Buddies all use the distilled water/ Red Line combo in our high compression street/strip Gassers that run at 170 on even the hottest days. Sent from my iPhone using H.A.M.B.
Good luck getting those screw in plugs out. Pop the easy accessible freeze plugs out and flush from there. When it runs clear . Put new plugs back in. Just did an engine that looked good until I popped 2 freeze plugs and the crud was half way up the block. Would not dislodge with normal back flush.
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