mysterious vanishing coolant....please help!

[Anonymous]

Hey Guys,
I need to ask for your help once again. I am at a loss.....My 66 200 is losing coolant and I don't know what the problem is, or where it is going. Here are the repairs I have done in the last three months to address this problem.....

* upgrade from two row to four row radiator
* water pump
* thermostat
* hoses
* radiator cap

at this time I did a complete tune-up including adjusting the ignition timing that was only slightly advanced.

after I did this, it ran cool for about two weeks, then I started losing coolant and it seemed to be going into the oil, so....I suspected a blown head gasket or a cracked head. Then I did these repairs.....

* installed remanufactured head
* new head gasket
* exhaust and carb gaskets

Here is the deal.....when the coolant is filled, it runs beautifully, and stays cool. After driving for about 20 minutes on the freeway.....the coolant level has lowered significantly, and then as the coolant lowers more, the temp. begins to creep up. I am not getting any coolant dripping into the passenger side on the carpet, but I have not done anything to the heater core.......I don't know what else to do. Any thoughts or suggestions would be deeply and desperately appreciated.

Thanks,
Ryan

 

[BIGREDRASA]

I hate to say this, but it sounds like a cracked block.
Do any of your plugs show signs of water?
Try this: Run the engine with the radiator cap off, then blip the throttle. Any leakage into the water jacket may cause water to gush out the radiator filler. If nothing, run it up to operating temp, with the radiator cap off, then blip the throttle. Again, any leakage into the water jacket may cause water to gush.

 

[MustangSix]

I'm assuming the rebuilt head was crack checked. First do a compression check, but I suspect you'll find one and possibly two cylinders on the low side. You might also do a chemical detection test for combustion gasses in the coolant.

I think you're going to have to change the head gasket again. When you start losing coolant that way and it's not on the ground and not in the oilpan, there's only one other place it can be going and that's out the tailpipe.

Pull the head, but this time also check the block to make sure it is true. Long, 6cyl blocks are prone to be out of square and you may need to have it surfaced. Using a machinists straightedge and a feeler gauge, you should find no more than .002" of gap when measuring corner to opposite corner of the block.

When you reinstall the head, torque the headbolts carefully in stages from the center out. Don't just pull the bolt down to 70 ft/lbs all at one time.

 

[BIGREDRASA]

Another thing, how old is your radiator cap? Are you getting coolant into the recovery tank? An old, worn out cap can cause loss of coolant, but it would go into the recovery tank.

 

[Anonymous]

Three things come to mind right off the bat, and shares the senitments of some of the previous posts.

1. cracked block
2. cracked head
3. bad head gasget

Depending on where the cracks may be, or where the head gasket is bad your coolant is being burned in the comustion chamber. Additionally, check for coolant in your oil. It will be either milky colored, or yellowsh looking.

Sorry, good luck

BIll

 

[Anonymous]

Thanks for your replies.

OK, I did replace the cap when I changed the radiator. I do not have a coolant recovery system. I just have a tube that drains coolant out to the ground. I do notice that the end of the tube is oftentimes wet, and I can sometimes smell coolant when the engine is hot. Could the coolant be draining out the tube for some reason? Should I get a recovery system?

The remanufactured head was checked for cracks and I did tighten the head bolts as you suggest. Seems like I got an increase in power when I changed the head & gasket and there is no more weeping of oil down the plug side of the block between block and head.

A couple questions;

1) Do I have to pull the block out of the car to have it checked and/or milled flat? Can it be done while in the car?

2) How do I check if the oil is milky? Do I drain the oil and look at it in a pan to do this?

3) Any thoughts about a problem with the heater core?

4) Any chance that my holding a baseball bat in a menacing way, using profanity, and making macho and unrealistic threats when the hood is open might help?

Thanks guys.....I really appreciate your help!
Ryan

 

[Junk-Falcon]

thers a

 

[MustangSix]

3. If the heater core were leaking, your floor would be wet and the windshield would be fogged up.

1. If the block is not straight, you will have to pull it.

The original radiator is not designed to run completly full of coolant. If you fill it to the top, it will overflow out the hose as it warms up. A coolant recovery tank is supposed to catch that and return it to the radiator as it cools off. Without the tank, once the system reaches a point where there is adequate space for expansion in the top tank you shouldn't lose any more unless the engine overheats. I recommend a recovery system so that the air space required in the top tank can be used to hold coolant instead. You will need a cap designed for that type of system.

2. If coolant is getting into the oil the oil pump and engine will begin to whip it into an emulsified material like mayonaise. You can drain a little from the pan into a clear jar to see if any is settled since water is heavier than oil, or you can pull the stick and see if you have mayo on the dipstick.

D. Threatening an American car with a weapon will not work. The car will eventually find a way to kick your ass. If you own a Peugeot or Renault that technique may work.

 

[XFlow_Fairlane]

that is too funny jack.

I have the same problem kinda in my car. loss of coolant with no puddles and once it reaches a certain point it stops. if I fill teh over flow it will be empty after driving a short distance but will hold it for days if I don't run the engine. it has always done this sinceI put the new head on ( head was resurfaced adn this happened with both a composite gasket and a steel shim.) heater core and all hoses are new the only thing not replaced is the cap (next thing to do)

nick

 

[rbohm]

8) have the rad pressure checked. mine needs to be replaced as the seems are leaking. even on new ones though the seems can leak. since you have coolant in the overflow tube, you might check to see if the cap is sealing properly.

 

[CobraSix]

I don't mean to be insulting...just want to check the obvious...

Did you burb the system when you filled it?

Otherwise, short of block problems, it sounds like your radiator cap may be old or too low of a pressure setting. I think the minimum is 13 psi. I'm running a 16 psi cap right now.

Slade

 

[addo]

It's gasket week, all right! My way of "burping" the coolant (nice term Slade; never had a car sick down my back) is to fill the radiator to 1" below the filler neck shelf and repeatedly squeeze the upper hose. You'll notice no more change when it's done.

Other one we found recently was when the water pump seal blew out. Lost a lot of water; you could see it trickling down the edge of the timing cover with the engine hot and running.

Hey, Jack - did I ever say I'm restoring a Renault (16TS)? It's kicked me more than I care to recall. Every part, every nut bolt and washer, is unique, application specific, and available for a princely sum from one source only... It's why I work on Fords to unwind!

Adam.

 

[Anonymous]

I have not "burped" the system. I have no idea what that is but I am willing to do it. Could it explain the disappearing coolant though? I don't quite understand Adam's way of doing this. Could someone explain this a bit more.

It isn't insulting in any way. If I have missed anything, I want to know about it. Thanks!

Ryan

 

[CobraSix]

Here we go...I'll explain as best I can.

When you fill up a cooling system that has been drained, there are air pockets in the cooling system that can not usually be removed by simply filling up the radiator. The radiator will appear full, but in reality, the cooling system is only about 50% full. You have not put any coolant into the heater system yet and various other locations. If you do not 'burp' the system after filling it up and check it later after the car has gotten to operating temperature, it will appear as if the radiator was empty. Since your car does not have enough coolant in there, it will start to run warm. It can also damage the water pump if left this way long enough.

How to BURP:
1) Drink lots of beer...oh wait...hold on.

1a) fill the radiator up until it is full. Wait a few minutes for the coolant to drain down, and top off.

2) Start up car, leave the radiator cap OFF of the radiator.

3) As the car warms up (usually 5-10 minutes) you'll start to notice the coolant level drop in the radiator.

4) As the coolant drops, keep adding more antifreeze/water mix to the radiator (slowly add it). Try reving the engine some to help warm the engine up more and pull more water through the cooling system.

5) Keep adding coolant until the level does not drop or it starts to overflow the radiator.

6) At this point, put a NEW radiator cap (minimum 13PSI cap) on the radiator.

7) Drive the car for about 10 minutes...go pick up beer.

8) go back home...let the car engine cool down completely (drink 6 pack of beer you just bought...again, slowly).

9) Next morning, open the cap and refill the radiator if needed (usually only a little bit if at all).

That is the method I usually use to "burp" (I think the technical term is 'purge') the cooling system. I would advise getting a radiator flushing kit. They usually ahve a funnel that fits perfectly in the radiator cap opening. Use the funnel. It usually makes it easier incase you overfill the radiator at little bit.

Do this method over grass, as you may get some overflow as you fill it up.

I think that is how I did it, I haven't done it since September since my car has been dissassembled. I will be doing it again this week though and I'll try to take some pictures.

Slade

 

[Anonymous]

O.K. Here comes Mr. 20/20 hind site

I started losing coolant and it seemed to be going into the oil,

As Jack said:

First do a compression check

One thing you didn’t mention are the rings. They could be worn or just failed in one hole, causing the coolant to get into the oil. A compression check will tell you for sure.
However, it sounds to me like you may have the radiator cap for a coolant recovery system currently on your radiator, without a recovery bottle. Check by reading the label on the cap.

 

[Anonymous]

This is a great help, thanks to everyone. I will do the compression test this week. The drain tube from my radiator comes from the top of the radiator,on the throat for the cap. The radiator cap is new. I checked and rechecked that it is correct....but I will check again.

Also, because of my amature mechanic standing I have no idea what a cap on a radiator does (other then keep the coolant from spilling out)....so I am not understanding what you mean when you write about the pressure rating. Any chance someone could explain this to me?

I probabaly shouldn't let the car see me getting so angry because I am beginning to think that it likes to see me freak out. Anyone else's car seem to take a perverse pleasure in causing you agony? Could it just be that my car would prefer an owner who is young, cute, female, and stacked?

Ryan

 

[Anonymous]

This ones easy so I can offer some assistance. The reason for pressure ratings on radiator caps is that without a pressurized cooling system the car would overheat very easily. At sea level water will boil at 225 degrees (I think, but now I'm not so sure). As you raise the atmospheric pressure the boiling temperature rises, like to 250 degrees, and the more you raise the pressure the higher the boiling point. I'm not sure what the ratio of pressure to rise in boiling point is but I know that early cars would routinely boilover due to low pressure cooling system. This is one reason why the early Fords (model A's and T's)ran 6.5-1 compression and made so little power. Well that and low octane fuel!! Hope this helps you understand why a proper rated cap is important, gotta keep that pressure in!!!

 

[CobraSix]

Ryan,

That was a good explanation above. Boiling temp at sea level is 210*F (or 100* C).

Think of it this way. As water heats up, what happens? It expands. If you left the radiator open that water will eventually overflow. If you put a regular non-pressure cap on it (which I don't know if they make, but theoretically) you do not let it expand and it builds pressure. The reason there is a pressure rating on the cap is so that the cap is the "weak link" of the cooling system. If you did not allow some pressure realese, you can theoretically blow out a hose, radiator, water pump, some other piece of expensive equipment. The pressure rating on the cap is the pressure it will allow the system to build to before it releases. Basically it keeps your system from blowing up.

Slade

 

[Anonymous]

This explains something that was going on with my car before I tore the engine out, when I would get to where I was going and shot the car off, after about a minute or two the coolant would flow out onto the floor, not a lot, but some....

Sounds like I had a bad cap.... it was the only thing in the system I have never replaced.... strange when you think about it, something so small and you just think, it looks OK I think I will just reuse it....


BY THE WAY, what is the correct pressure for a stock 200 rad cap and does it change at all depending on what is done to the car, for instance installing a 3 row radiator, or AC, or something?

 

[CobraSix]

Stock is 13psi, but a lot of people (including me) have been running a 16 psi cap just to help overheating. I did it when I was running a 2 row that was severly corroded (before I knew it was) to help my overheating problem. since I only used it for about a month before I got a new 3 row, I just kept the 16 psi cap. I think the rule is that it should be changed everytime you flush the fluid which should be every year or two.

Slade