How do YOU bleed your cooling system?

[89hatchman]

I have an overheating problem.

Lower hose is cool but the temp gauge rises to the H pretty fast. I think its an air bubble near the thermostat.

I bled the system by opening the bleeder screw, filling until water came out, put a funnel in the radiator and ran it hoping it would burp the bubbles out.

But nothing happened, upper hose is warm, radiator is cold, lower hose is cold.

So, how do you bleed your system? I'm amazed about how hard it is to bleed this thing...

[ill.]

Park it on a slight hill facing upward haha

[ST34LthyN1NJ4]

Originally Posted by ill.

Park it on a slight hill facing upward haha

pretty much what he said that or jack up the front

edit: also try searching there are tons of other threads that people have already made about the same issue

[ashtonroche]

Sounds like a thermostat issue. Could be air but yeah.

Here is my method. Jack the front of the car up so the radiator neck is at the highest point. Fill the cooling system until full, burp the hoses by squeezing both the lower and upper hoses till the air is out then fill it up and keep doing that till no more air bubbles come out.

Start the car, the level should go down as the wp pulls in coolant to start cycling it. Top off the coolant when it goes down. Keep it at the top of the neck. As it warms up to operating temp the level will rise but wait till you actually see it start flowing then fill up and cap. Ive never had an issue doing it this way. Do not open the bleeder. Its pointless really. This procedure has always worked. Key is to try and wait till the motor gets up to operating temp and the thermostat opens and the coolant level goes down again and then top off and cap. You will know when the t-stat has opened as you will actually see the coolant flowing through the radiator. When that happens just top it off and cap.

If your coolant never starts to flow and just keeps getting hotter and hotter its a pretty obvious sign that your thermostat is not opening.

[Chaluska]

Originally Posted by ashtonroche

Sounds like a thermostat issue. Could be air but yeah.

Here is my method. Jack the front of the car up so the radiator neck is at the highest point. Fill the cooling system until full, burp the hoses by squeezing both the lower and upper hoses till the air is out then fill it up and keep doing that till no more air bubbles come out.

Start the car, the level should go down as the wp pulls in coolant to start cycling it. Top off the coolant when it goes down. Keep it at the top of the neck. As it warms up to operating temp the level will rise but wait till you actually see it start flowing then fill up and cap. Ive never had an issue doing it this way. Do not open the bleeder. Its pointless really. This procedure has always worked. Key is to try and wait till the motor gets up to operating temp and the thermostat opens and the coolant level goes down again and then top off and cap. You will know when the t-stat has opened as you will actually see the coolant flowing through the radiator. When that happens just top it off and cap.

If your coolant never starts to flow and just keeps getting hotter and hotter its a pretty obvious sign that your thermostat is not opening.

^^^^this^^^^^

thats the exact way it has to be done.

and fyi, it takes about 15-20 minutes for the thermostat to open when sitting in the driveway, so dont think its going to happen in a few seconds.

you will see the coolant rushing like a river in teh radiator, thats the point when you top it off and cap it.

[brndck]

This.
Lisle 24610 Spill-Free Funnel:Amazon:Automotive

/thread

[racepar1]

You're bleeding it correctly. As stated previously, you can try and jack up the front end just to be safe. Also, squeeze the radiator hoses to try and agitate any air that may be trapped. If the thermostat won't open then it's probably stuck. I've had brand new thermostats come defective and stick closed before.

[rcdad123]

my method is drilling 3 3mm holes next to each other on the thermostat. if it`s got a jiggle valve, i cut it off and drill it to 3mm and then one more 3mm hole on each side of the first hole from the jiggle valve. i mount the thermostat so that the three holes are on the highest point, like 12 0clock if you look at it like a clock. i then use the funnel that attaches to the radiator neck with adapters, like the one mentioned above. fill up radiator, and once its filled, i keep the funnel at least half filled for another 10 minutes or so while the engine is running. i also switch the heater temp switch to hot so the coolant will circulate through the heater core. turn the heater fan on so you can feel the air if its getting warm. this method works on 99% of the cars i do/done. except for the ones with a heater hose that is higher than the radiator. in that case, i just disconnect the highest heater hose and fill up radiator till coolant comes out of the disconnected heater hose. reconnect heater hose then start engine and run till both upper and lower radiator hoses get hot.

[racepar1]

Originally Posted by rcdad123

my method is drilling 3 3mm holes next to each other on the thermostat. if it`s got a jiggle valve, i cut it off and drill it to 3mm and then one more 3mm hole on each side of the first hole from the jiggle valve. i mount the thermostat so that the three holes are on the highest point, like 12 0clock if you look at it like a clock.

This is a good tip for anytime you're installing a new thermostat in any car. ALWAYS cut out the jiggle valve, and drilling an extra bleed hole or two is always a good idea. This makes it easier for air to bleed past the thermostat when closed and prevents an air bubble from preventing it from opening.

GOOD TIP MAN!

[EDacIouSX]

You gotta be kidding me.... didn't i just see a thread on this last month?

[89hatchman]

Alright, so I've tried everything here except drilling new jiggle holes in the thermostat. I've got the front jacked up, opened the bleed screw and filled it up till coolant came out, took the jiggle valve out, made sure the hole is at the 12 o clock position, squeezed the upper and lower hoses a shit ton, and double checked to make sure the thermostat worked by boiling it (it opened like a charm).

I don't get it. My temps just keep going up and up. I don't get it man...

[ashtonroche]

Was the thermostat opening and you seeing coolant cycling through? If not then you might have a waterpump issue, impeller might have separated from the shaft.

Are you getting any bubbling with very small air bubbles as your watching it warm up with the cap open and causing it to overflow out. If so your headgasket is probably done for.

Not hard to diagnose whats happening.

[89hatchman]

Originally Posted by ashtonroche

Was the thermostat opening and you seeing coolant cycling through? If not then you might have a waterpump issue, impeller might have separated from the shaft.

Are you getting any bubbling with very small air bubbles as your watching it warm up with the cap open and causing it to overflow out. If so your headgasket is probably done for.

Not hard to diagnose whats happening.

I can't "see" it open since its installed right now, but it opened and closed when I put it in a pot of boiling water.

The water pump is brand new, I manually checked it before I installed it. It's pumping. Not to mention, when the thermostat was removed the temp was at normal levels so the water pump isn't the problem.

I'm trying to bleed the system right now using the bleed screw and a funnel on the radiator. So I expect to see air bubbles. But not too many are coming out. And the Head gasket should be good. I rebuilt the whole thing about a week ago. Its a felpro, the coolant isn't mixing with oil, and my compression readings are nearly 155 exactly across the board (hoping it'll go up when the rings seat)

[ashtonroche]

155 is normal compression for a det.

Again with the car cold, keep it off, fill it up, burp the hoses, start the car and see if the coolant goes down, fill it up again, let run until full operating temp is reached, toping off and burping the hoses as you go until the thermostat opens. You should see the coolant in the radiator start to flow through when the thermostat opens. If that doesnt happen then its not opening. Also if it hasnt opened and your temp needle just keeps rising then it may be that your temp sending unit is bad and its not really overheating.

What are you basing the overheating on?

If its not bubbling as its running and maybe giving it a little throttle then headgasket is still good. It doesnt have to be mixing water and oil to be putting exhaust gases into the system. But you will see a bunch of small bubbles if its doing so.


Again what are you basing the overheating on.

[89hatchman]

Originally Posted by ashtonroche

155 is normal compression for a det.

Again with the car cold, keep it off, fill it up, burp the hoses, start the car and see if the coolant goes down, fill it up again, let run until full operating temp is reached, toping off and burping the hoses as you go until the thermostat opens. You should see the coolant in the radiator start to flow through when the thermostat opens. If that doesnt happen then its not opening. Also if it hasnt opened and your temp needle just keeps rising then it may be that your temp sending unit is bad and its not really overheating.

What are you basing the overheating on?

If its not bubbling as its running and maybe giving it a little throttle then headgasket is still good. It doesnt have to be mixing water and oil to be putting exhaust gases into the system. But you will see a bunch of small bubbles if its doing so.


Again what are you basing the overheating on.

I'm basing the overheating on the cluster temp gauge. It may be air tricking it into saying its overheating, or it may actually be overheating, I don't know. Thats why I'm trying to bleed the whole cooling system.

[Heytheremr2]

Originally Posted by rcdad123

my method is drilling 3 3mm holes next to each other on the thermostat. if it`s got a jiggle valve, i cut it off and drill it to 3mm and then one more 3mm hole on each side of the first hole from the jiggle valve. i mount the thermostat so that the three holes are on the highest point, like 12 0clock if you look at it like a clock. i then use the funnel that attaches to the radiator neck with adapters, like the one mentioned above. fill up radiator, and once its filled, i keep the funnel at least half filled for another 10 minutes or so while the engine is running. i also switch the heater temp switch to hot so the coolant will circulate through the heater core. turn the heater fan on so you can feel the air if its getting warm. this method works on 99% of the cars i do/done. except for the ones with a heater hose that is higher than the radiator. in that case, i just disconnect the highest heater hose and fill up radiator till coolant comes out of the disconnected heater hose. reconnect heater hose then start engine and run till both upper and lower radiator hoses get hot.

And you just drill the holes with a drill bit? Just want clarification.

[Frank_Jaeger]

No, you drill them with a screwdriver. Set the thermostat in a clamp and wiggle it as hard and fast as you can with the screwdriver. If you use a drill bit, you'll ruin everything.

[codyace]

fill it up, put cap on half way. squeeze upper hose until it sucks the coolant lower. refill/repeat. Drive to work the next day with cap half clicked, top off. Done. No fancy jacking it up, no heat on, nothing special.

[towlie]

Originally Posted by brndck

This.
Lisle 24610 Spill-Free Funnel:Amazon:Automotive

/thread

What I do is

Take 2 liter soda bottle
Cut in half
Use top half, flip upside down
Use Electrical tape wrapped around nozzle so it fits radiater (custom fit siiiiick)

It's only as much as the soda lol. Leaks a little but w/e. works wonders

[e1_griego]

Brokedick-spec.

[towlie]

Lol it is. But if you're in a pinch it works fine

[cotbu]

Originally Posted by towlie

Lol it is. But if you're in a pinch it works fine

In a pinch??? That's funny. That soda bottle shit is part of my kit! I know that if I tape my funnel that crap will fall out of the radiator before the thermostat opens.