Coolant System Problems

[davemeradith]

1.when i was retightening the drain plug for the radiator, i over-did it and snapped the end off flush... at least its tight and holds my coolant, but any suggestions on removal so i can replace?
2.i replaced degas bottle today. went smooth, except it still overheats. i bled the system using the thread in tech section to a T, but im still having problems. i have no coolant leaks, and i've bled until i got a solid stream and refilled degas about 5x now, only to have her overheat soon after. PLEASE HELP.

 

[joegr]

It sounds like you still have a leak, you just haven't found it.
Did you get that coolant flush recommended in your other thread?

You should be able to get the remains of the plug out with a bolt-out. (Basically, a drill bit that turns backwards.)

Just put the new one in hand tight.

 

[davemeradith]

hoses comn off bottom of thermostat housing and to left were super hot while ones on right were cold. could thermostat need replaced? and engine fill cap was bubbling directly from center where hex tool goes but not bubbling over or leaking from lip of cap. could this little bubbling cause the problem?

 

[joegr]

hoses comn off bottom of thermostat housing and to left were super hot while ones on right were cold. could thermostat need replaced? and engine fill cap was bubbling directly from center where hex tool goes but not bubbling over or leaking from lip of cap. could this little bubbling cause the problem?

Yes, the thermostat could be bad.

You just said there were no leaks, now you admit that the engine fill cap is cracked and leaking. It must be replaced. A tiny leak that you might not even see is enough to cause failure, let alone one as big as you describe. It's not so much the little bit of coolant lost that is the problem. The problem is that the system can't fully pressurize when hot, and when cold it sucks air back in. The air then causes it to overheat next time. (Air does not transfer heat nearly as well and liquid does.)

 

[davemeradith]

sorry joe when i think leak, i think when my degas was cracked and draining onto ground. i assumed since it was just bubbling when overheating, it wouldnt be a problem and it would stop when the overheating did. do you think any auto stores would carry our engine fill caps? i know i can find a thermostat but im trying to finish this tomorrow and youre making me think its the cap not the thermostat. thanks again for all your help man.

 

[oddball]

You can get the cap at the dealer. Might take a couple of tries to get someone to know what you're talking about and find one in stock.
Parts stores won't have it.

If you have a bit more time, there's the aluminum version for the Jags which should be much more resilient to cracking.
If you stick with the plastic, use a properly sized hex drive and do NOT overtighten. The cap is very weak in that area.

 

[centason]

sorry joe when i think leak, i think when my degas was cracked and draining onto ground. i assumed since it was just bubbling when overheating, it wouldnt be a problem and it would stop when the overheating did. do you think any auto stores would carry our engine fill caps? i know i can find a thermostat but im trying to finish this tomorrow and youre making me think its the cap not the thermostat. thanks again for all your help man.

Replace both and kill two birds with one stone. One is broken and the thermostat is questionable. Then get a replacement plug.

 

[davemeradith]

You can get the cap at the dealer. Might take a couple of tries to get someone to know what you're talking about and find one in stock.
Parts stores won't have it.

If you have a bit more time, there's the aluminum version for the Jags which should be much more resilient to cracking.
If you stick with the plastic, use a properly sized hex drive and do NOT overtighten. The cap is very weak in that area.

i ordered the jag part from rock auto for $50 just waiting for it. i just need a quick fix for a week or so til its in.

 

[davemeradith]

fixed cap and replaced thermostat. she still runs hot periodically while driving but has yet to overheat again. when u bleed the air and get a steady stream of coolant should the stream stay constant until you run it dry? or will it stay steady when thermostat opens and system is recirculating and slow or stop when it closes? can you leave the degas bottle open when bleeding air to fill coolant as you lose it or does this introduce air into the system? with NO visible leaks (yes joe none lol) and it still heats up a lil SOMETIMES it makes me think i still have a little bubble and im not bleeding correctly. ive been through the steps time and time again and im.getting the same results. fyi 2000 v8

 

[TooManyToys]

You still probably have some air pockets, those should work there way out over a couple of days. If you have hills or ramps at a parking garage a few slow trips up and down can work the air out of the motor too. Check the reservoir at the end of each day as you may find you have to add a few cups of coolant to get it within the min-max range.

 

[msgtusmc]

Old trick might work. Leave cap off degas bottle, squeeze upper left radiator hose repeatedly until all air is out.

 

[davemeradith]

You still probably have some air pockets, those should work there way out over a couple of days. If you have hills or ramps at a parking garage a few slow trips up and down can work the air out of the motor too. Check the reservoir at the end of each day as you may find you have to add a few cups of coolant to get it within the min-max range.

i thought it was a closed pressurized system? it was my understanding NO air can be released without using the bleed method.

 

[tireman]

radiator drain plug

Yes i broke mine too. Just leave it there unless it leaks. You may never have to drain it again, who knows. If you really want it out, just drill thru it.

 

[davemeradith]

Yes i broke mine too. Just leave it there unless it leaks. You may never have to drain it again, who knows. If you really want it out, just drill thru it.

thats my plan. it holds with no leaks but ill purchase one(theyre cheap) and when/if it ever needs a flush again, ill have a replacement. til then im not gonna touch it.

 

[TooManyToys]

i thought it was a closed pressurized system? it was my understanding NO air can be released without using the bleed method.

Well they are all closed pressurized systems .

Using the bleed hose gets a lot of the air out, but it's still not perfect. In the times I have changed fluid or broken into the cooling system (draining) I have found some residual air despite following the manual's procedure to the letter. And before asked, I do fill the front motor cap until all air has burbed out at that point.

 

[joegr]

i thought it was a closed pressurized system? it was my understanding NO air can be released without using the bleed method.

Actually, a correctly working degas bottle will vent minor amounts of air from the system. The cap on the degas bottle vents any pressure over 16 PSI, and also has a check valve to prevent the cooling system from having a vacuum when it cools off.

 

[davemeradith]

Well they are all closed pressurized systems .

Using the bleed hose gets a lot of the air out, but it's still not perfect. In the times I have changed fluid or broken into the cooling system (draining) I have found some residual air despite following the manual's procedure to the letter. And before asked, I do fill the front motor cap until all air has burbed out at that point.

sorry im not so familiar with the cooling system on cars. i thought when people said their car worked itself out, it must be an open system(since its releasing air itself) unlike ours where its closed, and you have to manually use a bleeder valve. glad i got clarification. i also filled the engine fill cap until it was full without any burping.

Actually, a correctly working degas bottle will vent minor amounts of air from the system. The cap on the degas bottle vents any pressure over 16 PSI, and also has a check valve to prevent the cooling system from having a vacuum when it cools off.

i thought, "it isnt letting air in with the cap off, so how with it on could it let air out?" so good to know joe.

thanks for the help and info guys.

 

[TooManyToys]

I should have been more specific. When I talked about getting the air out I meant getting the air out of the motor itself and into the coolant reservoir. Once it's there with coolant replacing the air within the motor, the coolant level will drop in the reservoir.

 

[davemeradith]

I should have been more specific. When I talked about getting the air out I meant getting the air out of the motor itself and into the coolant reservoir. Once it's there with coolant replacing the air within the motor, the coolant level will drop in the reservoir.

ahh together with what joe said that whole process makes sense now