Coolant never full, the overflow is overflowing.
 

Ok.... well I did the block weld this weekend in my car (along w/ 99 spec tail light conversion)... and somthing I noticed is I can never get the coolant all the way full.

I don't remember this being normal.... what could be wrong? (on a side note... my car didn't gurgle anymore after the block weld)

This morning I took the cap off and couldn't see coolant so I went to add some... I would add to the top... turned my back.. look again, and it was all gone. So I continued to do so until I started to hear water hitting the ground. Looked to see the overflow tank was overflowing.

I'm going to flush it again tonight to take out the copper block weld... is there anything I should check?

Thanks in advance...
chris

I'm sorry but I don't see how you can be displacing coolant to the overflow by simply filling your system. Where are you filling the coolant at? There was a GREAT description on here last week about how the two radiator caps work. Tom

i had the same problem. unitl i changed the ast out for an aluminum one.

I am filling the coolant at the neck not the AST and not the overflow.

I'm not quite sure why it's doing it either but it is. I can sit there and pour water in and watch it go down as my overflow tank fills up.

I have a pettit ast.... I wonder if my cap has gone bad :confused:

Do not fill the coolant at the neck. You prably have a bad seal on the neck which is leaking water onto the ground as soon as it is full. Fill from thermostat housing and AST. I was having this problem but it wouldnt leak until the car was drivin and then shut off. Turned out to be just bad caps.

the overflow tank is the tank behind the passenger side headlight right?

I have no leaks at the neck. I think I'm going to take out the intake and see if I can get a better look at whats going on.... I wonder if it is just bad caps.... could that cause the water to go straight to the overflow tank?

I can't quite figure out what the heck is up. Becuse it sends all the water to the overflow my add coolant light will come on until the thermostat opens up. Then water finally gets to that part of the neck and the add coolant light goes off.

Hmmmmmmmm.... anyone else have any ideas?
Where can I order a new ast cap and new filler cap?

Yup... thats it.

There is a small hole on the top of the body of the tank (before the neck goes up) that you can see from under the hood if you look good w/ a flash light.... that hole (w/ a gromet) is where the water is comming out.... looks like the safty for the overflow so if there is too much water it will poor out from there.

One thing that I never quite got was why water never splashes out of the overflow hole when you are filling it up. Could someone post the link about how exactly the overflow bottle works? I also don't understand how the overflow bottle is able to hold the coolant at a lower level than the filler neck and ast, even with the all the caps off. Last time I checked the coolant it had somehow gone down in the filler neck and AST and gotten displaced into the overflow. I didn't get any add coolant light, but I just ended up siphoning the overflow and then putting that back into the AST to return it to the normal level. I can't seem to recreate the problem, but maybe it takes a long time?

az_lynx,
Fill at the engine neck, and change your CAPS. Also check the hose from the AST to the OVERFLOW tank, might have a crack in it...

Jason
www.jt-imports.com

The reason the coolant doesn't, or shouldn't any ways, go straight to the overflow is because the pressure cap holds the coolant back from the overflow tank line's inlet. When the engine heats up and pressure builds up past 13 (or is it 16) PSI the seal springs back allowing water to flow into the overflow until the pressure is below the caps rating. If you pull the AST cap and fill it with coolant, after the AST is full any additional coolant poured in will drain through this line into the overflow tank.

az_lynx, is it possible you somehow managed to install the AST in a location lower than the top of the filler neck?

Keep burping - it might take a week to get all the air out.

Use the upper hose near the firewall in back of the intake manifold - it's the highest spot and easy to do daily. Keep an extra gallon of distilled water in reach at all times.

The other issue may be that if you did not FULLY purge the system of all old coolant your block weld may not have worked, in which case you'll need to start all over again, It's a pita, but the only way it will be effective.

You did take off the 14 mm bolt at the bottom of the block and run fresh distilled water throught the system with the heater on high at least 3 times before installing the Block Weld,- right?:eek:

Ok, so the way I understand it is, the car heats up, pressure builds, causes the coolant to rise up to the AST hose, it then flows into the overflow while the cap simultaneously lets the pressure out. Then when the car cools off, the cap doesn't work in reverse, so the negative pressure pulls the coolant in the overflow bottle back through the hose and into the AST. Therefore anything interfering with that negative pressure will prevent the suction effect from occurring and thus the overflow tank keeps getting higher and higher. Is this right? What still doesn't make sense then is how a higher pressure cap would help draw coolant back out of the overflow. I would think it would be the reverse since a higher pressure cap would result in a higher running pressure, more pressure to overcome before the cooling effect will create a negative pressure to draw the coolant back in.

Damn, four years of college, graduate school and then another four years of A and P certification......
I don't get totally lost too often, but it has now OFFICIALLY happened. I need to sleep on this one.
I still think it has to do with air in the system.
We're talking hydraulics here folks.....

Anyone - anyone?:scratch: :confused:

RonKMiller: I flushed the system about 14 times in all (including takeing out the engine block bolt) w/ degreasing.

Ok.... so the cap is suppose to keep the water from going to the overflow until the pressure is built up... correct?

So.... if I take the hose that goes to the overflow (top hose on the AST) off... and have the AST cap on. Then take off the coolant cap on the filler neck and pour water in there and it starts comming out the top nipple of the AST (overflow) then it's safe to say I have a bad cap?

If so... where can I get a new cap?

EDIT: Nevermind... I just found out it's a generic 13lb cap... I'll stop at autozone on my way home tommorow and grab a new cap and see if this fixes my problem. Then it's time to drain out the block weld and refill the system.

Then off comes the UIM to find my primary turbo problem :D Only a couple more weeks till sevenstock!

Hey az lynx,
 

Please tell me you didn't put some "stop leak" sh_t in your car. I thought you just put in a new motor. I helped you with the engine stand question, remember? What's up?

What is block weld, and why did you put it in? I was going to try to shed some light on your problems, but if you put some stop leak additive in your car, your freakin' doomed. It totally plugs up all of the small coolant lines that go to the turbos and throttle body, not to mention the radiator! I don't care what the bottle says, it WILL plug everything up. That means new motor, turbos, coolant lines, ...................

Good luck dude.

Jeff

Re: Hey az lynx,
 

Oh my god! It's not even my car, and i'm having a heart attack.:eek:

Re: Re: Hey az lynx,
 

OH GOD, ROFLMFAO. Tom

I think he put the old motor back in, it still had good compression.

Was that my heart jumping out of my chest when I read aRex-7's post... yah, it was. Good luck buddy - hope your engine is alright...

Not for long.:(

The block weld fix is a temp only fix. Mazdatrix had some good info on why NOT to use it in their catalog...

aReX-7 is pretty much right.

Jeff

Re: Hey az lynx,
 

Hey... I put in CRC Copper Block Weld... several people have put it in their cars with plenty of success. I ran it through the system and I am in the process of flushing it out right now. Then I will flush the system several times and refill. The stuff is not goopy at all it just has copper flakes in the that heat up and seal ONLY where air is present :confused:

Several people have had success and now w/ the new AST cap my car is running better than ever. My AST cap was fine before before the block weld but I think I damaged it one of the 15 times I was taking it on and off to flush the system.

Now after the block weld tho I have no more gurgling after shutdown and the car is running cooler than it was before!

If it doesn't help then it's no big deal.... my motor has good compression but it's also got 97,000+ miles on the original motor. If it goes out... no biggie I just figure this might give it a few more play miles while I plan out what turbos I want to go w/ :)

We'll see what happenes.

You say that it will only seal things where air is present, but I hope you do realize that there is small amounts of air often trapped in your cooling system for the first few days after you change your coolant. Especially in the radiator. I usually have to add alittle coolant for the first three or four times I drive after I change.

Case in point:

I recently worked on a 93' FD for a local guy who was experiencing a boil over effect after shut down. He kept adding coolant, and adding coolant, but it just seemed to keep boiling into the overflow tank. After replacing the AST cap, I took apart his cooling system and I found it to be full of flakey, scaley copper crap. The coolant line leading to the turbos was about 60% plugged, and the line to the throttle body was COMPLETELY blocked. No flow. Also, his radiator was partially packed full of the crap too, and there is just no way to get all of that stuff out of there. Later he told me that the previous owner had overheated the original engine and tried to use a stop leak product to "squeeze out a few more miles". What they actually did was doom the new engine beacuse the already overworked cooling system had now lost about hallf of it's cooling capacity. I am pretty sure he will be putting engine #3 in that car very shortly.

Back to you:

At this point, you can't take back the fact that you used this stuff. What is done is done. However, I would pay extra close attention to the coolant temps in the near future. Especially in stop and go traffic. And the stock gauge will not do. It will only start to move above normal ASFTER the car starts to overheat. Get an aftermarket gauge installed. If it starts to run over 100 deg. C, I would start shopping for a new radiator and replace ALL of the coolant lines. Maybe even the heater core if necessary. Also, remember that you should flush the system in the reverse direction that it flows in the cooling loop. That is your only hope to get some of that stuff out of there.

Good luck.

Jeff