Coolant Leaking....

[malv]

I was driving around today (95 Formula) and the "low coolant" light came on, then went off. It did this a few times during the afternoon. Eventually, I noticed the temp go into the red and the "check gauges" light pop on (although the "low coolant" light was not on...). So I headed back home, nothing smoking yet, and just as I pulled into the driveway I heard a POP from under the hood. I opened the hood and it was steaming all over and the coolant was leaking (bubbling explosively) from where it gets filled. The steam cap to the radiator was still intact, and was not hissing or anything.

I know this could be a lot of things, but anyone have any ideas? I am no expert on cars, but like to figure things out and try to do things myself wherever possible. If anyone has some time and wants to help me diagnosis/ fix it, hit me up!! I'm trying to make the car ready for a coast to coast roadtrip in a few months, and this kinda throws a damper on things :mrgreen:

[Tru2Chevy]

So what popped off, the cap on the overflow?

- Justin

[malv]

That's the thing... nothing popped off that I could find! The cap is still on, and I'm stumped. I can't figure why the coolant light came on and off, and then stayed off while the car overheated.
From what I've read, it could be the water pump, or head valve?

[transmaro93]

if you still have a stock style mechanical water pump... unless the pump itself is leaking or its making crazy noises i doubt its that... i would start with a thermostat.... cheapest fix...

[BonzoHansen]

Where exactly is the coolant leaking from? Pics might help.

[sweetbmxrider]

might be the petcock (drain plug for radiator)

best bet is to get a pressure tester for the radiator.

[Pampered-Z]

When you see the low coolant check the level right away!

If you went into the red the coolant would boil / expand enough to come out the overflow and probably enough to burst a weak hose or push it off or even possible blow the low coolant sensor out? Had this happen when my electic water pump went. Pinned the temp gauge and all the collant blew out the cap of the overflow tank!


You also want to check you oil and make sure it's not looking milky! Restart the car and look for white smoke ( blown head gasket or worst = warped/cracked hear or block).


Refill the radiator up to where the vent hose for the heads connects to the rad. ( about 2" down from the rad cap, and above the low collant sensor. Start the car with the cap off and and look for leak(s). no leaks then keep running it and montor the coolant, you will most likely need to keep adding water. What you want to look for is no bubbles, when the engine gets up to operating temp ( around 190 = stock termostat). You should start to look at the hose to make sure none are collapsing, and see coolant going into the radiator from the head vent hose. IF you don't see collant flowing and the temp is above 190 either the tremostat is stuck closed or your water pump has failed.

From there, after the it cools down remove the thermostat, you should see collant flowing from the head vent tube right away.

Just be VERY careful, when the thermostat opens it could release air pockets which can force hot collant out the top of the radiator!

[97transam]

If that LT1 was that low on coolant...it's going to take awhile to get all of the air pockets out. Took me a couple of weeks after the cam install before it settled out.

The bigger problem is how long was the block running after in went into the red zone? If it was for awhile...I wouldn't be driving it "coast to coast" now.

Hey John, couldn't he check the oil dipstick to see if it is "full" now? Meaning if there was a major block problem with anti-freeze leak. Would save time doing anything else.

[malv]

Update:
Thanks for all the good info guys!
I could not figure it out, so I took it by my local Midas to see what they could come up with.

Unfortunately, they were pretty cryptic. They told me that it could be a number of things (yeah no $*@!) and that I should start by replacing the water pump and thermostat. They said that they pressure tested the hoses and the pressure was fine, which tells them that the thermostat is not blocked... aside from that, they said they can't pinpoint a problem like this.

All together with parts and labor, I'm looking at just under $800 (~350 parts + ~300 labor) bucks, and they don't guarantee that the problem will be fixed (if it's the head gasket or something else).

I told them I'd get back to them lol.

To anyone out there with experience at this, is what they said correct? Is the pricing reasonable? Can't they just start with the thermostat which is like a $40 price instead?

And to answer some other questions that people asked:
1. I mis-stated the problem- it is not a leak per say. It overheats and boils up out of the overflow cap.
2. The oil is not milky white.
3. Pampered-z- awesome advice, but honestly the latter part of it is beyond my skills (scared I may mess it up more!)

[sweetbmxrider]

i wouldn't chuck parts at a car without knowing what the problem is.

[97transam]

Good news on hearing that there isn't antifreeze into the oil.

There is also the radiator itself is. Maybe it's gunked up (cooling fins are blocked) and needs a flushing.

Do you know if the fans are running?

Just seeing if there is something that can be fix more easily before spending the bucks...

[LTb1ow]

Have you bled the cooling system?

Could just be a large air pocket causing it to over heat.

[BonzoHansen]

Have you bled the cooling system?

Could just be a large air pocket causing it to over heat.

of course that begs the question how did the air get there. assuming the car at one point ran fine and nothing was done prior to this event.

[LTb1ow]

Granted, but we are working with info that has changed a few times now... first it leaks, now it didn't?

Does it overheat all the time?

[malv]

My apologies. As I said, I am no expert :-?
When I saw coolant spewing from my car, I referred to it as "leaking (bubbling explosively)". But I guess that was a poor choice of wording.

As far as I can tell, it is NOT leaking from any hose, plug, orifice, etc. The only place that I have seen it come out of is from the overflow cap, which I assume (based on other posts) is due to the overheating.

I have had the car since November, but only driven it a few weeks before having it garaged all winter. I had driven it a few times before this thread (after winter), with no problems and only recently have had this problem. My first post in this thread was the first time that it has overheated (for me- I can't speculate as to the previous owner).

I haven't driven it since then, except for today when I brought it to Midas.

I have not bled the system, but I found a good tutorial so I think I will toy around this weekend.

I hope that helps!:-P

[Tru2Chevy]

Just another free thing to check - look under the front of your car and see if the airdam is there and intact. Without that, you will be losing a lot of airflow through the radiator, and it will allow the car to overheat much more easily.

If you aren't familiar with it, the airdam is the black plastic piece in the left center of this pic:
http://www.lt1engine.com/tech/wp-content/uploads/2008/04/freeramair4.jpg

- Justin

[sweetbmxrider]

My apologies. As I said, I am no expert :-?
When I saw coolant spewing from my car, I referred to it as "leaking (bubbling explosively)". But I guess that was a poor choice of wording.

As far as I can tell, it is NOT leaking from any hose, plug, orifice, etc. The only place that I have seen it come out of is from the overflow cap, which I assume (based on other posts) is due to the overheating.

I have had the car since November, but only driven it a few weeks before having it garaged all winter. I had driven it a few times before this thread (after winter), with no problems and only recently have had this problem. My first post in this thread was the first time that it has overheated (for me- I can't speculate as to the previous owner).

I haven't driven it since then, except for today when I brought it to Midas.

I have not bled the system, but I found a good tutorial so I think I will toy around this weekend.

I hope that helps!:-P

alright so its just popping the radiator cap open? there is an overflow tank hooked up, correct? it is part of the battery tray. the temperature is climbing all the way to the red zone, or very close? do you see/hear/feel the fans coming on? they should come on with the temp gauge around the 3/4 mark. when the car is dead cold, is the radiator filled with antifreeze? when does it overheat, while driving, idling, always?

[malv]

Still no luck but bad luck...

I found that some other guys have had similar problems on another thread, and found a tutorial on how to bleed/flush the system. So, I tried that yesterday. The car is now idling around 230, but I am seeing white smoke, with water and oil in the exhaust. I don't see any coolant in the exhaust, but from what I've read so far, the white smoke would be an indicator that the coolant is being burned off due to a blown head gasket. The oil pressure has started to decrease as well, but when checked, looks like regular color to me.

Would a blown head gasket also account for oil in the exhaust? It is literally sludging up at the ends of the exhaust tips (I don't think that's normal, but correct me if I'm wrong). Kinda annoyed at how the "professionals" at Midas didn't notice that (unless it just started happening, but I kind of doubt that; then again, the mechanic who I dealt with said something along the lines of "wow that's a big engine"... :-?).

Sorry for the delay in posts, I have the car in West Paterson, but I'm in Rockaway most of the week, so it's not every day that I can work on it. I do appreciate all the replies though!

More answers to questions:
Yes, the overflow tank is hooked up.
When it overheats, it goes all the way into the red zone.
The fans are kicking on.
It has only overheated while driving, but I have not let it idle from a cold start to check, other than today after the flush.
I do have the airdam on.

[Tru2Chevy]

White smoke does usually indicate a bad head gasket....did you smell the exhaust at all? Coolant smells sweet when it burns, so it's easy to detect.

- Justin

[Pampered-Z]

How did you flush the system? Did you flush out the block or just the radiator? Total system should be about 3 gallons.

Do not run the engine any more! Drain the oil and check it closely. If coolant is getting into the oil you'll kill the bearings!

OK, so stay away from the shop! If the leak is that bad then the collant system should most likely (not 100% always) not holding pressure.

If your getting white smoke and what appears to be oil ( could be coolant in the exhaust "washing out" carbon) but you have issues. It probably also killed an O2 (why idle is screwy).

At this point, I'd pull all the plugs and look at them. Remove the Ign and Fuel injector fuses, and turn the engine over and have someone look for fluid spitting out 1 or more of the spark plug holes. Then you want to do a leak down test on each cylinder to see if you have warped or cracked the block or a head.


Sorry, but this does sound like it's going to be a pretty serious issues, but lets hope I'm wrong! But for now you have to check the engine is not badly hust before you run it and look for what caused it to overheat.

[malv]

Hey just an update--

I got the head gaskets replaced. One of them had a small tear in it.

Aside from that, according to the mechanic, the coolant fans are not kicking on properly. He jumpered the relay (?) and said that the fans came on, but he could not get them to automatically kick on when the car hit high temps. He doesn't specialize in electrical, so for now, he rigged it so that the fans stay on when the car is on.

The low coolant light still comes on lol. He told me that there is a small hole on the bottom of the overflow reservoir, so I ordered up a new one and will replace that once it gets here. Hopefully that will take care of the coolant problems.

After that, I just have to find out whats going on with the fans!! I read up on some older threads that had similar issues, so I guess I'll start there. Just can't wait till it's 100% drivable again!

Thanks for all the input!

[Pampered-Z]

Sensor the computer uses to turn on the fans is in the front of the water pump, check the wires/conector and change that out first.

[deadtrend1]

Try cleaning the sensor in the radiator for the low coolant light. Dexcool has a habit of gumming it up.