Radiator Boiling Over (2 Viewers)

[mattressking]

All you need to do…

1. Properly bleed system with bleeder on radiator until stable.
2. Confirm upper hose pressurizes when hot lower hose is warm but not hot at operating temp.
3. Perform compression test hot and cold for comparison.
4. Tell us if it continues to boil, if it does either your water pump or tstat is failing or your hg is leaking.

 

[AYM707]

All you need to do…

1. Properly bleed system with bleeder on radiator until stable.
2. Confirm upper hose pressurizes when hot lower hose is warm but not hot at operating temp.
3. Perform compression test hot and cold for comparison.
4. Tell us if it continues to boil, if it does either your water pump or tstat is failing or your hg is leaking.

I'm not sure i understand 2? What do you mean? How do i test that?

 

[mattressking]

I'm not sure i understand 2? What do you mean? How do i test that?

Put your hand on it. Top needs to be firm and hot and lower firm but not as hot. This confirms your cooling system is working. Applicable to any car on the road, as are all the other steps

A cold or collapsing lower hose means you have circulation issues

 

[brian]

You do that compression test yet?

 

[mattressking]

You do that compression test yet?

Someone on a forum that actually does what people correctly recommend? No never, ever.

 

[AYM707]

Someone on a forum that actually does what people correctly recommend? No never, ever.

compression test kit ordered...let's see

 

[AYM707]

I just wanted to check my understanding.
1- remove all spark plugs. unplug the ignition coil. block fuel line.
2- test one cylinder at a time
3- crank engine a few times per cylinder

 

[pb4ugo]

And throttle wide open. You want the cylinder to hit maybe 4 to 6 times or more. What ever # you decide, make sure each cylinder hits the same # of times.

 

[AYM707]

And throttle wide open. You want the cylinder to hit maybe 4 to 6 times or more. What ever # you decide, make sure each cylinder hits the same # of times.

just making sure...throttle open wide...means i should be pumping the gas pedal (with no fuel)?

 

[John McVicker]

Don’t ‘pump’ as in push the pedal to the floor, release and push it to the floor again.

CORRECT WAY: push the pedal to the floor & leave it there. I keep it to the floor with a long 2x4 or similar.

 

[Grayscale]

New radiator cap? It's job is to prevent boiling coolant from escaping, to recover coolant when the engine cools down (you can hear it happen), and to keep coolant from boiling in the first place.

I'm pretty sure that the radiator fill neck is above the head, so as long as the head is slightly tilted up, all you need is a funnel for not making a mess. Parking it with the slope in your favor can't hurt, however, I've changed coolant parked the wrong way, no issues.

 

[fjwagon]

Good recommendations. It may not matter but I would try it when the engine has ran for a while. Manually hold the throttle opened at the carburetor and if have a remote starter that helps. The other tool that I use when this type of troubleshooting is I check the temp with an infra-red thermometer. I have a fluke but u can use just any brand. At point, removing the head maybe something you will have to do. And may even consider taking it to a machine shop and have it checked. Just have a box of sandwich bags, sharpie and take pics as you stuff and bag the hardware. Or use a bucket and throw everything it as you remove it which I would not do if it's your first time. Good luck.

 

[73FJ40]

I didn't read whether the radiator cap has been replaced..

 

[77mustard40]

I didn't read whether the radiator cap has been replaced..

Sounds like the OP is on to an engine rebuild

 

[73FJ40]

Sounds like the OP is on to an engine rebuild

We need a rule that the cost and complexity of a proposed "diagnostic test" be included in the recommendation so newbies can prioritize their efforts w.r.t. their bank account.

I'll start: radiator cap: about $20.
Complexity: press down; leftie loosie, righty tighty.

 

[AYM707]

I didn't read whether the radiator cap has been replaced..

have not replaced the cap; but if there was a leak there...boiling coolant / water would drop shot out. or drops of water when its cool.

and total agree with the complexity vs cost rating. looking for a cheap / easy solution; but beginning to think my radiator is shot. the system / radiator was empty for over a year. the vehicle was in an underground garage but the moist / cool air would have made the difference.

 

[pb4ugo]

1983 FJ45 - stock

After a 45 / 60 min drive normal highway; my radiator fluid is boiling / overflowing from reserve tank release.

I am running a mix of anti-freeze + water and there's no thermostat. My temperature sender was dead. I had previously flushed & cleaned the system several times before and the system was empty for a long time. I feared a head gasket leak as the coolant colour changed to an dirty olive. Also at start-up, there are a "few" drops of fluid coming out of the exhaust. But that stops after a while; but no smoke.

I have jacked the front help release the bubbles, there was plenty. But was convinced, it was a head gasket leak - maybe a minor / small leak. Ordered some head gasket sealer (K-Seal & Blue Devil) and a tester. Tested it, and the fluid remained blue; but there were a constant stream of bubbles coming out. Ran it for about an hour (mostly at idle), the fluid never changed colours, but the bubbles did not stop.

Does this mean I have a very small leak or should I be looking at some place else? The water pump is functioning; when you squeeze the radiator pipe, you can feel fluid flowing. I have replaced the temperature sender and will take it for another test drive.

Debating if I need to use the head gasket sealer? Appreciate your input.

This is a little confusing, did you replace the thermostat?

I wouldn't add any kind of sealer or mechanic in a can into anything.
Condensation in the exhaust is not uncommon, especially warming up? Is the exhaust steaming with white smoke that smells sweet once warmed up? Does the engine run smooth or have a miss?

This contraption is just replacing the stock overflow tank and according to your description, appears it's working as it should. It's results are to be expected. Does your test kit indicate there are exhaust gases present?

You can borrow a cooling system pressure tester at a big box auto parts store. See it the system holds pressure and look for leaks while pressure is applied. You can test the cap with it too.

 

[73FJ40]

have not replaced the cap; but if there was a leak there...boiling coolant / water would drop shot out. or drops of water when its cool.

and total agree with the complexity vs cost rating. looking for a cheap / easy solution; but beginning to think my radiator is shot. the system / radiator was empty for over a year. the vehicle was in an underground garage but the moist / cool air would have made the difference.

Umm, if you're "boiling over" where does the boil over leave the radiator and get to the overflow tank?

Maybe through the radiator cap? Maybe consider that a "leak"?

And if the radiator cap is malfunctioning and not holding rated pressure, the boiling point of water goes down 3 degrees for every 1 psi drop in radiator pressure.

New radiator cap is an easy and cheap first step.

 

[pb4ugo]

Umm, if you're "boiling over" where does the boil over leave the radiator and get to the overflow tank?

Maybe through the radiator cap? Maybe consider that a "leak"?

And if the radiator cap is malfunctioning and not holding rated pressure, the boiling point of water goes down 3 degrees for every 1 psi drop in radiator pressure.

New radiator cap is an easy and cheap first step.

The over flow tank is fed by the small hose next to the rad cap(circled in the pic). As the coolant gets to operating temp and the cooling system builds pressure, coolant is forced to the tank. As the coolant cools, it is sucked back into the rad. It is a closed cooling system. The tank has to have a/f in it when the engine/cooling system is cold for it to work properly. Using the proper cap for the application is important.

 

[AYM707]

This is a little confusing, did you replace the thermostat?

I wouldn't add any kind of sealer or mechanic in a can into anything.
Condensation in the exhaust is not uncommon, especially warming up? Is the exhaust steaming with white smoke that smells sweet once warmed up? Does the engine run smooth or have a miss?

View attachment 3763485

This contraption is just replacing the stock overflow tank and according to your description, appears it's working as it should. It's results are to be expected. Does your test kit indicate there are exhaust gases present?

You can borrow a cooling system pressure tester at a big box auto parts store. See it the system holds pressure and look for leaks while pressure is applied. You can test the cap with it too.

Let me clarify...no thermostat. I changed the temperature sender so i could understand what was going on.

My contraption "IV solution" was mainly to get the bubbles out of the system; which happened. Agreed, as the engine / coolant gets hot, it is typically forced out into the reserve tank and then when it cools, it is sucked back in. If there is not enough fluid in the tank, air get pulled in. That's why i make sure there is alot of fluid in my bottle before the cooling process. If there is a leak in the cap or elsewhere, then the fluid would not get sucked back in. right?