I am having problems with the cooling system in my 66 toronado. It overheats when idling after about 30 minutes, which I am pretty sure it due to A. old belts possibly slipping (water pump is probably not getting turned as fast as it should). and B. rusty cruddy coolant possibly blocking the radiator/ engine passages. I have new belts for the engine (still have to put them on) but I have yet to flush the old coolant because I am not sure what to do about rust in the system. I have never had a car with such nasty coolant in it. When it overheated, it puked out mud colored water (sludge) and it stained the concrete it was sitting on) I'm also thinking the radiator might be partially clogged.
Can I use CLR or something similar to flush the cooling system prior to putting in new coolant (and if so, how much do I use)? Also, does anyone know where to find the lower radiator hose for the first gen toronado? I found the top hose, but the bottom hose is not available through auto parts stores.

 

If you have rust in the coolant, it's most likely from the radiator itself slowly disintegrating. Flush the system until the water drains out clear, which means you'll have at least cleared the loose stuff out as well as push whatever loose stuff might have gotten into passages within the engine itself. Then get a new radiator as it's time to junk the one you have.

 

The rust is from the engine block,the radiator is most likely restricted from coolant flow from the rust.Radiator replacement most likely will cure the overheating at idle but the cause is coming from the engine block and rust. A good flushing of the cooling system is needed prior to radiator replacement.The t-stat should be replaced and fan clutch should be looked at assuming no headgasket issues.Nick

 

Last summer I went through this when I had to drain the coolant to change an intake gasket. The radiator looked like it had a lot of depostis on the end of the tubes(looking inside from the cap), but I never seemed to have any over heating problems. Only if I filled the radiator up to the very top would it ever "puke". So I leave it down about 1.5 inches from the top and she's fine.


What I did as good measure, I removed the radiator, flushed it out with hot water, and then I filled it on a flat surface with vinegar. I left it sit over night and drained it out. Then I did it again. I may have poured boiling vinegar into the radiator the second time for good measure, not sure if that really helped or not. I heard about CLR or other chemicals to clean them quickly, but I was nervous it might cause more harm than good, and I didn't want to ruin it.


I also used radiator flush treatment from Prestone with water and ran that for 200 miles(which I did in a weekend trip). Sad to say the flush didn't seem to do a whole lot, but my coolant wasn't like mud either.


So that's what I did and it seemed to work. It would have been easier to just buy a new radiator, but I some of the typical ones have mixed reviews and I just didn't want to deal with it.

 

Flushes generally work on minor clogging. What you describe seems more serious and I doubt a flush is going to fix it. Years ago, the fix was to "rod" the radiator. That meant removing the tanks and then pushing rods the same shape but slightly smaller through each of the tubes, pushing the crud out the other side, then re-soldering the tanks back on. That also assumes that the tanks and the core are in good enough condition to unsolder, clean and re-solder. With a 35-50 year old radiator, that may be difficult.


I think you are looking at a new radiator after a good flushing of the engine block. I would avoid anything with plastic (cheap) tanks.

 

No, the radiator is brass. It doesn't rust.


Yes.


It may and it may not. As you note, the fan clutch is also a likely culprit at idle.
Does it also overheat on the road?
And who lets a fifty year old car sit and idle for half an hour?


That's because that's how high you're supposed to fill it - up to the line embossed in the tank, where it says "FILL LINE" (or something similar).

Finally, if the coolant is very thick and rusty, I would STRONGLY advise you to remove the block drain plugs and flush the block out through them. Sometimes a very thick layer of rusty sediment can accumulate down at the bottom of the block, in the area of the bottoms of the cylinders, which can be several inches thick, and which displaces coolant and prevents flow. This needs to be removed. Anything you can do to get it out, including inserting an angled tool into the plug holes to break it up, removing the heads and gouging it out with a screwdriver, or pulling the motor and having the block boiled out, will help a great deal.

- Eric

 

the radiator is original (brass)
the car has not overheated on the road (although at this point, the car is only driven on short trips a couple miles from home).
as for who lets a 50 year old car idle for half an hour? -that would be my dad. He let it idle to charge the battery (I dont think it takes that long to charge a battery...even with a 55 amp alt)
interesting about sediment collecting in the bottom of the block. How hard is it to remove the drain plugs?

 

If it overheats idling for a half an hour you have a flow problem.Coolant and or air flow.Replacing freeze-core plugs are not an easy task because of access.If the coolant is as bad as stated the core plugs are probably very thin from rust already.Nick

 

I have essentially let my car idle for more than half an hour a few times in heavy traffic on very hot days without a problem, but I set it up to be prepared for that, with a good radiator, fan shroud, and heavy duty fan clutch.


It's not easy to remove the drain plugs (different from the freeze plugs), but it's not impossible.
They're on the sides of the engine, one or two on each side, below the exhaust manifolds, possibly covered by the starter or the crossmember.
If you can get a wrench up under there, they should come out.
It's easier with the manifolds off, but that's a royal PIA itself, unless you've had them off lately.

- Eric

 

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and an impact tool helps remove the 9/16 hex head 1/4 NPT block drain plugs. New ones are readily available. After that, you typically have to poke at the deposits behind the plug to dislodge enough to get flow out... all over the floor and your arms. Have a large drain pan handy and newspaper or whatnot for what the drain pan misses. Then flush a lot. Maybe put the water hose end up to the block drain and force water in there as part of the ceremony.