KonkeyDong

First of all, I would like to thank all of you for reading, and ANY informative or educational help is certainly appreciated.

2000 Trans Am M6, 53k miles, currently a DD. I am going to give as much information as I can.

Title was rebuilt in 2001 due to a rear end collision, car sat for 7 years and I bought it in North Carolina from the gentleman who bought it from the re-builder. Drove it home 10 hours to Indiana, virtually no problems. When I arrived home, I parked it and noticed coolant was bubbling in the reserve. I decided to do some research and observe it in the mean time.

Some days later, less than a week, the problem escalated when I noticed coolant leaking from underneath my car when I came back out from the mall in the parking lot. Popped the hood and the reserve cap had popped off. The plastic lid is stripped and would not tighten down without becoming loose again from overtightening.

I read and found out I should start simple with replacing my radiator cap. I did so and things were okay until the other day when I noticed my car overheating, reaching temps over 260 degrees (according to the gauge). I was in the city, so I shut the car down and waited for it to cool until I could get home. I had to stop and start 4 times before I could get there, hopefully not warping or damaging the aluminum block or anything else.

The next day I jacked the car up, popped the radiator cap off, and started it cold. Let it warm up, watched the coolant level drop, and refilled a few times before it leveled off. Turned the car off, put the cap on, and went about my day and the next week normal, no overheating issues. First time I have ever "burped" the radiator, if in fact I did and it wasn't just blind luck.

A week later I go to change my brakes, way overdue, and the front passenger side caliper has a seized piston. Replace both front calipers and pads, rear pads, bleed my brakes and take it for a test spin, brakes were awesome! When I got back, I let her sit for a minute, then decided to check the coolant level, which was pretty low, so I topped it off again, may have let air back in when I did that, I dont know? But, I took a shower, and headed out for a cruise.

Maybe 10 miles down the road, I notice it was overheating again, so I pull over and let her cool off. Luckily my girlfriend and I were heading to a local fall festival, so there were some yard sales along the roadside. We stopped at these and let my car cool, repeating the cycle from before in order to get home again.

This morning I go out and try burp air out of the system without success; the coolant just rushed out like a volcano and it started steaming, overheating. I went and got some more Dex Cool, let her cool down reasonably well for a couple of hours and tried to burp the system again.

Here are the steps I followed via information Ive gathered from online, but I still have questions.

1. Jack the car up and remove radiator cap.
2. Turn climate control so the heat is as hot as possible, but not ON.
3. Start car and wait for it to warm up.
4. When coolant level drops, bubbles come up and I top off.
5. No more bubbles, shut car off and put cap on.

Issues: This last time I turned the heat on after the vehicle had warmed up, not really thinking, but wondering if it would clear any possible air bubbles out of my heater core? Also, when I am filling the coolant the first time, it will rise more, overflow, then drop. Sometimes I fill it back up, but it will just drop way back down again. Other times, it seems like when the engine has warmed up, it will start steaming and bubbling over. I have squeezed all the hoses, but the big one to the right of the radiator often has a loud, almost KNOCKING sound, and then it goes away.

Obviously I am not a certified mechanic, but I do have experience with the basic maintenance of vehicles. This is getting a little over my head and I feel as if I may cause some permanent, long-term damage.

My plan at this point is I have ordered an OE rad cap replacement and it will be here Wednesday. If I cant get this figured out by then, I plan to take it somewhere to get flushed, not sure I want to try, and find out what they have to say. The metal replacement rad cap I got from Autozone doesnt seem to be quality at all.

I have a million ideas in my head, but no one to consult with or talk to. There was a small bit of corrosion on my old rad cap, orange in color, and a mechanic told me that probably means my water pump needs replaced. But Ive read thats fairly rare with these cars and there could be all of these little simple things causing the same issue. Hea/t has always worked, until this last time, so I dont think its the t stat, unless it went out just now, but it worked until this last time I tried to burp it and turned the heat on. When I was driving afterwards, it began to over heat. I turned the defrost on full blast and it cooled it down to just over 210 until I got to NAPA to exchange some parts. On my way back that trick did NOT work, and I noticed my heat is not near as warm as before.

Its home and staying until I figure something out. I am in college full time, other than that I am currently unemployed, on a tight budget, and do not drive much.

Also, the first time it overflowed in the mall parking lot, I walked to a local gas station and picked up some pre diluted dex cool that was green? I have used that entire gallon to top off and refill my reserve, but I read today mixing it with the orange dex cool causes sludge.

My fans work, my heat USED to work (until earlier today), replaced rad cap, ordered OE rad cap.

One last thing, I do not observe ANY leaks, just lower coolant levels, like its getting blocked up somewhere or something? I think this current rad cap doesnt seal correctly and may be letting coolant out in the form of steam. I poured one entire gallon of coolant in today. I plan on popping the cap off and taking a look in a little bit.

Again, any help is much appreciated.

.boB

iTrader: (1)

My first thought is a small leak somewhere, so you're losing coolant slow enough that you don't see it. Second thought is a bad head gasket.

Go down to your local Autozone, and borrow a coolant test kit. They'll charge you $80, but you get it back when you return the kit. Go through the entire test procedure, starting with a cold engine. It takes <1 hour, and you should have some good answers.

KonkeyDong

It runs fine and doesnt produce white smoke. ill rent the pressure checker tomorrow. Any other ideas? I just changed the oil and it wasnt milky or discolored.

1FastBrick

iTrader: (16)

Cooling system could be plugged or blocked. You could also have a stuck thermostat.

You also need to make sure the E-fan and relay are functioning correctly.

KonkeyDong

Fans kick on anytime temp gauge shows above 210. T stat seemed to be working properly until last time I turned on the t stat while burping the radiator, now the heat is semi warm, not hot while running. So perhaps I screwed it up last time? The fans are fine if theyre kicking on, right?

I assume if there is blockage, it will have to be dealt with when flushing the system?

ChevFTW

Just first make sure you have/buy the right radiator cap and that you fully bleed the system. Don't just assume it's 100% bled after you stop seeing bubbles. Sit there on idle and then rev it for ages with the cap off and your front end jacked up.


Wait what..
What do you mean by you turned on your t stat?
What do you mean by your radiator hose makes a loud knocking sound??? Is it okay? Is there something stuck in there? Does that hose feel like the other main hose when you squeeze it?
What do you mean by your heat used to work? Do you mean your heatER? If so, then it appears you do have a blockage somewhere in your cooling system. Check for cool hoses/pipes. Could be a blocked heater core.

Phuk any other coolant that isn't green.

KonkeyDong

Yes, I turned the heatER on while trying to burp the cooling system this last time, and now my heat barely gets warm.

The hose to the right of the radiator makes an obnoxious loud noise when it starts to warm up and burp the air out. The hose to the left forces fluid up and down in the radiator when I squeeze it, the one to the right just seems to be normal, except that loud noise.

How do I clear blockage, will a flush do so, even the heater core?

I am currently running the orange dex cool, so I would have to flush the whole system with water a few times before switching to green. I just picked up the green stuff when I was having the first real issue, and I didnt know it could cause issues mixing with orange dex cool.

KonkeyDong

Picked up a pressure tester from AZ. Get home, pop the rad cap off. Coolant level is low, like half way. Top it off, but the level immediately falls a couple of inches. I put the pressure tester on, it doesnt even get a reading or build any pressure?! I take the pressure tester off and the coolant level is back down to half or so again.

Also, I checked my reservoir, and the car hasnt ran in almost 24 hours and the coolant is all the way up to the top of the dipstick. With the cap off of the reservoir, you can see the coolant level about even with the bottom of the battery id say.

I dont see any major leaks, but there is so much coolant still on the parts that Im not sure I would be able to see a small leak, but there are some drips beneath the water pump on the passengers side. Perhaps time for new water pump gaskets?

LS6427

iTrader: (2)

Blown head gasket. Everything points to that. If the pressure cannot build in the coolant system when you do a pressure test than its pushing the coolant somewhere.....if its not going on the ground, it can only go into the engine....or the floorboard through a leaking heater core. Is the passenger floor wet????

And be careful using pressure testers......if the head gasket is torn and the coolant is pushed into a cylinder and fills it too much, the next time you start the engine....BYE-BYE engine. You will need to pull it out of the car and have it rebuilt.
Coolant system pressure tests should ONLY be done with all 8 spark plugs removed.

......and even if you pass an 18-20psi pressure test......it does mean the head gasket is not blown somewhere. Because combustion is a WHOLE LOT more powerful than 20psi. So combustion will enter the cooling system in that fight. Check the coolant with a tester to see if there's any exhaust getting into the coolant. This will tell you if you have a blown head gasket.

While you're driving the combustion from the cylinder where the torn head gasket is...is pushing air into the cooling system and slowly, while you are driving, pushing coolant past the radiator cap and into the over fill container.

.

KonkeyDong

Oh boy. So have it towed somewhere and let them take a look.

KonkeyDong

From what you said about the pressure tester, Im assuming I shouldnt try to start it again, or even dare to drive it the local AAMCO?

nine8ss

iTrader: (5)

Turn the engine over manually via socket on the crank and make sure there is no binding (hydrolock). If it turns over a few times then you should be fine to start it.

LS6427

iTrader: (2)

Well...its a gamble. I'm not trying to scare you into towing the car away....but it would suck if you literally broke a rod internally by trying to start it. The coolant went somewhere....if its sitting in a cylinder and you start it....and the coolant is taking up just enough space.....you can break a rod. Then you are finished.

Or you can take all the spark plugs out and turn it over for 5 seconds to push all the coolant out of the spark plug holes.

Maybe take all 4 spark plugs out of the drivers side....very easy. You can take them all out in 15 minutes. Maybe you'll find one of those 4 holes has the coolant in it.

nine8ss: also has a good recommendation if you don't want to take the spark plugs out.

.

KonkeyDong

*UPDATE*

The hoses on the water pump were reversed. Weird it took almost a year for it to cause an issue...

Orange Juice

iTrader: (3)

Glad you found it was something simple.

KonkeyDong

Yeah. Me too. Blew my mind. Also switched out dexcool for universal.