Overheating

[HooliganUK]

I have had for a brief time coolant coming out of the overflow pipe. I thought maybe it's me overfilling the tank. Last week the temp gauge started moving up and down rather quickly, when I was stationary it would go up, when moving it would start going back down. I assume this was due to cool air being forced in under the hood. Any suggestions where I should start, maybe new Thermostat?

Thanks.

Steve.

[YellowRose]

Overheating

The first thing you should check is the fluid level in the expansion tank. It is only supposed to be about one third full as I recall. The idea is for there to be enough room in that tank to allow the heated coolant to rise without overflowing out the drainage tube. If it is to full, you may want to draw some out. After that, depending on how long it has been since the radiator was flushed, you might want to do that. flush it really well, and refill it with the appropriate amount of coolant/water combination. Or check the thermostat next and see if it might need replaced.

[jopizz]

Your car is naturally going to run hotter standing still then moving. You have no air going through the radiator at idle and your fan is at it's slowest speed. How high is your gauge reading. If it's more than 2/3 over toward Hot then you may be overheating. The gauges are not very accurate. As Ray suggested your overflow tank should not be overfilled. Coolant should be at the very bottom of the tank when cold. A number of things can cause overheating; a clogged radiator or block is the most common problem for older cars. I recommend getting a digital thermometer and measuring different parts of the engine block and radiator to get an accurate reading of the temperature.

John

[Dan Leavens]

Steve John and Ray have made some very good suggestions. I had a similar problem with my 60 as it over heated when waiting to get into a car show. Blew a lot of out the expansion tank and of course onto the asphalt . When I was driving home noticed the temp gauge up and down.

Took it into get an oil change and had them do a complete rad flush which when watching the old crap come out through the clear plastic tube was amazed. Too many years without looking after the coolant Since then no problems Sooo if you can't remember the last time it was done or don't know if it has been done probably a good idea. Like your plate number

[simplyconnected]

I'm with Dan as I also totally agree with John's and Ray's suggestions.

Now for my two cents... At idle, your water pump is not moving coolant. As John said, when your car is stopped, the only air going through the radiator is from the draw of a slow fan, which ain't much.

Dan touched on a VERY important point, 'lack of maintenance'. Good, name-brand antifreeze contains three essential ingredients, water pump lube, anti-corrosion/anti-rust agent, and glycol (which lowers freezing and raises boiling points).

Here's the deal... If you leave antifreeze in your system too long, the pump lube goes away and the phosphoric acid neutralizes as it eats rust. The only thing left is anti-freeze. The affects corrode your head gaskets (because they are steel) and your core plugs. This all happens silently and without notice until your cooling system starts getting hot.

It takes years, but our engines are fifty years old! When the water passages rust open in your head gaskets, the rear cylinders get very little or no water because flow takes the path of least resistance. The core plugs may rust through and start to leak as well.

Remove the core plugs and use a garden hose to flush out your block. Any other method will not flush as well. I use brass core plugs.

If you still have overheating issues after the block flush and you know your pump and radiator flow well, the head gaskets must be changed.

Also, change your DOT3 brake fluid every three years. - Dave

[Yadkin]

I'm partial to coolant flushes that use an additive with clear water, then you drive the car a significant distance. Then you flush repeatedly until all the junk comes out. I did that to my 05 Mustang at 110,000 miles and even the overflow tank is clean.

[Rock&Roll Firebird]

Is it possible that the core plugs for Squarebirds are not available on Rockauto? I have only fount this set on Mac's:

http://www.macsautoparts.com/ford_thunderbird/ford-thunderbird-soft-plug-set-brass-for-352-and-390-and-428-v8-1958-66.html

[Rock&Roll Firebird]

And regarding flushing the radiator - is it worth giving the radiator for a chem flush to a 'specialized' company or the flush using the available radiator-flushing additives advised earlier does more-less the same job?

[Joe Johnston]

Usually the shops here in the US use stronger chemicals that will dissolve build up better than what you can do yourself. They also pressure test and repair leaks afterwards too. Really clogged radiators require the removal of the tanks and a rod pushed through the tubes to force the build up out of the core. Guess it all depends on how clogged your radiator is.

[jopizz]

Is it possible that the core plugs for Squarebirds are not available on Rockauto? I have only fount this set on Mac's:

http://www.macsautoparts.com/ford_th...8-1958-66.html

They are available from Rock Auto. They are listed under Engine-Cylinder Head Plug.

John

[Rock&Roll Firebird]

Thank you John, I'd be surprised if the Rockauto wouldn't have these...

[Rock&Roll Firebird]

What about putting a slight mixture of the citric acid with a distilled water for few of the cleaning cycles? It does an awesome job on dissolving calcium and stone sediments...

[simplyconnected]

Use whatever solution you think will work.
We use phosphoric acid, found in many products like "CLR" (which means, Calcium, Lime, Rust):

CLR is available in most hardware stores in the USA.

Temperature makes a huge difference as most acids work much faster if heated. I'm sure you can find phosphoric acid in other products where you live. It's usually green in color if that helps.

[davidmij]

When I removed my freeze plugs I was surprised at all the mud like crud that was caked in there. If your engine has not been rebuilt lately definitely do that. Dave Dare, why do you say; "At idle, your water pump is not moving coolant." I had thought that the fan clutch spun at lower idles to keep the air flowing at a stop, but at higher rpm's the fan slipped and let the blow thru air cool the radiator?

Here's what I did with mine;
I took it out of the car, straightened all the mushed and dinged spots so the air would flow through better. It wasn't in bad shape, but every little bit helps.
I then hosed out the fins from the engine side to the front side - a little bit of dirt and such washed out there too.
I then laid the thing flat with the hose side up and filled it with distilled white vinegar. I let it set over night and then some - about 16 hours.
Next I heated it via propane torch all along the tubes, I could hear a little boiling vinegar every once in a while.
I emptied it and flushed it thoroughly with the garden hose on high.
Then I reinstalled it and filled it with water, ran it till hot, and then drained it - did this several times to get all the anti freeze out.
Then I used Prestone radiator flush as recommended.
I flushed that out by draining the radiator, filling with water, running until it flowed hot, then draining the radiator again. I repeated that several times until it ran clear.

I topped it off with one and a half gallons of anti freeze and it's running much cooler. At stop and go cruising speed it's around 195. I took it down the highway and it's just over 190. Ran it up and down an open stretch of highway at 3000 rpm, stomped on it up hill to 4000 rpm and it stayed between 190 and 195. Heck of a lot better!

I have since then removed the expansion tank and it runs at the same temperatures just fine. It's great to have that tank out of the way.

Dave J

[simplyconnected]

When I removed my freeze plugs I was surprised at all the mud like crud that was caked in there. If your engine has not been rebuilt lately definitely do that. Dave Dare, why do you say; "At idle, your water pump is not moving coolant."...

Dave, it looks like you answered your own question.

If your cylinders are caked with crud, how on earth can the water pump flow coolant at idle speeds?

The idea is to keep coolant on every surface of your cylinders. If flow stops, steam bubbles form on the iron, which further holds back coolant from touching the metal surfaces. You already know what steam does in a system, it must be allowed to escape before too much pressure builds.

Vinegar works in coffee pots but notice, they apply heat and run the pot through its cycle. Plain vinegar takes a lot longer at ambient temperature.

Yes, I know you used a propane torch but pay close attention to what the sounds are telling you. If the hollow core is open for example, heated coolant will flow, carrying heat with it. If you get to an area where it immediately boils, flow has stopped in that core because it's full of lime and deposits.

What do you do? I let the acid eat more lime... BTW, the more lime it eats, the weaker the acid concentration becomes. You can freeze or boil some of the water out of your vinegar to make it much more concentrated. I use phosphoric acid because that's what is inside Prestone. Phosphoric acid is about $11/quart. Vinegar is a lower grade and cheaper acid. Both are environmentally friendly.

So, your cooling system depends on air flow AND coolant flow or it cannot carry heat away. What you did to clean your radiator (heat exchanger) was very good. It proved itself on the road test. Most radiator shops couldn't be bothered, soaking someone's radiator for days. They want to sell you a new one and install it in minutes.

Don't shoot yourself in the foot by eliminating the expansion tank. Its main function is to carry air to the highest point in your cooling system. If another area becomes the highest point, it will have a big bubble. You don't want that to happen in your engine.