Coolant overflow puking-89A4
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From: altered state
St. Jude Donor '05
Coolant overflow puking-89A4
Level in overflow always appears to be the same, does not siphon back into radiator when rad. is low. Noticed lately after shutting the car down Im loosing coolant from the overflow cap/. Rubber gasket seems Ok visually yet leaks, new 16 lb rad. cap, too.
Didnt know the overflow was pressurized, and why wont it siphon back in the radiator?
Btw, car is running cool when all this happens. Took a long cruise tonight, car ran about 170 all the way. Soon as I got out of the car I saw coolant drppping from under front pass. area near headlight bucket.
Didnt know the overflow was pressurized, and why wont it siphon back in the radiator?
Btw, car is running cool when all this happens. Took a long cruise tonight, car ran about 170 all the way. Soon as I got out of the car I saw coolant drppping from under front pass. area near headlight bucket.
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If the system is losing pressure, then this is going to happen.
Sounds like you are having the same problem I originally had. You have to check the hose going from the rad to the overflow, then inspect for any visible leak.
If you stick your head under the nose, notice where the coolant is leaking from. The rubber cushions pop through the lower shroud/subframe, and that is where I first noticed my leak. The radiator, if its leaking, will leak through those holes to the ground.
Sounds like you are having the same problem I originally had. You have to check the hose going from the rad to the overflow, then inspect for any visible leak.
If you stick your head under the nose, notice where the coolant is leaking from. The rubber cushions pop through the lower shroud/subframe, and that is where I first noticed my leak. The radiator, if its leaking, will leak through those holes to the ground.
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From: altered state
St. Jude Donor '05
Ill check it out in the AM. Tired of adding water to this thing.
One thing I did notice is in the morning the cap still has plenty of pressure when I release it, Ive been assuming the radiator is good or it would have pissed it out?
Why is the overflow cap leaking coolant out of it after its shutoff, yet wont siphon back in the rad. Im missing something here.
One thing I did notice is in the morning the cap still has plenty of pressure when I release it, Ive been assuming the radiator is good or it would have pissed it out?
Why is the overflow cap leaking coolant out of it after its shutoff, yet wont siphon back in the rad. Im missing something here.
Last edited by cv67; Mar 30, 2006 at 01:26 AM.
Team Owner
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
The overflow isn't pressurized on mine. Take a closer look at the cap.
The coolant gets hottest about 15 minutes after shutdown. It's still expanding at that point. If you want to check and see it siphon back in, you'll have to wait longer.
Maybe something is forcing pressurized air into the water jacket and overcoming the cap pressure. Wonder how that could happen.
The coolant gets hottest about 15 minutes after shutdown. It's still expanding at that point. If you want to check and see it siphon back in, you'll have to wait longer.
Maybe something is forcing pressurized air into the water jacket and overcoming the cap pressure. Wonder how that could happen.
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From: altered state
St. Jude Donor '05
I didnt think those caps were pressurized, either, could there be a vent in there thats gunked up? Ah, the problems of a 17 year old car.
Beats payments, wtf.
Beats payments, wtf.
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Head gasket can cause it, though there should be other symptoms, it is still possible.
But look at that as a last resort.
The overflow is not pressurized. The pressure at the rad. cap will decrease allowing the spring to move, and this suction effect will pull fluid back into the radiator. If the system loses pressure through a leak, which will be pretty fast, then it wont be able to suck it back in.
But look at that as a last resort.
The overflow is not pressurized. The pressure at the rad. cap will decrease allowing the spring to move, and this suction effect will pull fluid back into the radiator. If the system loses pressure through a leak, which will be pretty fast, then it wont be able to suck it back in.
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From: altered state
St. Jude Donor '05
This is a sign of exhaust gases in the system. A pressurized rad will not allow a siphon to take effect.
Car doesnt run hot, but when startig the car in the AM, it has gone from running just a touch rough to sounding like it has a dead cyl for the first minute or two til it clears up. May explain a slight ( and random) misfire I get.....Been chasing it firever, could be a bit of water in the system. -And I just got called in to a test only facility for smog the other day....
Ill have to pressurize it...If its a gasket going bad, I may have to retire the car for awhile. Probably due to running super lean for the last few years (discovered that one on the dyno a while back-bad MAF).
Crap!
Thing is when coolant is full, car runs fairly cool . Oh well.
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Le Mans Master
Joined: Apr 2000
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From: Shelton CT
I had the EXACT Same problem in the '92 LT1 I just bought.
Drive it, temps never get above 190-195F, got home, idled to 216 when parking it, turned car off, and it started gurgling and pushing coolant out of the overflow container in the nose.
Next day I got a new radiator cap and new thermostat, everything fine now. Car heats up to 235, fans go on, I shut it off, no gurgling or loss of coolant..
If your coolant has no bubbles in it while running, it is NOT a headgasked. If it has no foam or oily residue in it, it is NOT a headgasket.
Drive it, temps never get above 190-195F, got home, idled to 216 when parking it, turned car off, and it started gurgling and pushing coolant out of the overflow container in the nose.
Next day I got a new radiator cap and new thermostat, everything fine now. Car heats up to 235, fans go on, I shut it off, no gurgling or loss of coolant..
If your coolant has no bubbles in it while running, it is NOT a headgasked. If it has no foam or oily residue in it, it is NOT a headgasket.
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Team Owner
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From: altered state
St. Jude Donor '05
I just bought a 16 lb cap from Vatozone awhile back now that I think about it and thats when the "losing thing started".
In fact, later that same day after pulling in the DMV parking lot the lower radiator hose blew off-Came out from my appointment to find the entire ground area around the car doused in coolant ....COuld a defective cap cause that kind of pressure?
In fact, later that same day after pulling in the DMV parking lot the lower radiator hose blew off-Came out from my appointment to find the entire ground area around the car doused in coolant ....COuld a defective cap cause that kind of pressure?
Burning Brakes
Joined: Nov 2005
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From: 1992 LT1 6 speed Cayman Islands
If your radiator is not pulling coolant from the overflow tank as the engine cools the problem almost always is the radiator cap gasket or the hose to the overflow has a hole. If this happens the radiator pulls air in as it cools not the coolant from the overflow.
Change the radiator cap again and see if this does not cure the problem.
Change the radiator cap again and see if this does not cure the problem.
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From: altered state
St. Jude Donor '05
Originally Posted by donhall
If exhaust gases are entering the cooling system, your op temps will be normal until enough coolant is displaced by the pressurized gases.
It may take 30-60 minutes, depending on the size of the head gasket leak, if there is one.....
It may take 30-60 minutes, depending on the size of the head gasket leak, if there is one.....
Thread Starter
Team Owner
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From: altered state
St. Jude Donor '05
Originally Posted by donhall
You are correct, but in this case there is pressure in a cold rad, which would lead one to suspect an exhaust leak into the cooling system through the head gasket.
Ill still replace the cap, looks like I better start saving my duckets for a motor a little quicker. Hope this sucker passes smog..
Last edited by cv67; Mar 30, 2006 at 11:02 AM.
Le Mans Master
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From: San Diego, Ca
I had no trouble passing smog with a leaking head gasket which is an issue on the early aluminum head motors - particularly the '89. GM issued a Bulletin and redesigned the gaskets and the 113's (subsequently removing the language that the change was to stop the galvanic corrosion that was occuring due to the incompatibility of the materials that were used). Do yourself a favor and pull the seven & five plugs. Compare the two - most leak at the rear or south side of # seven and you will usually see the difference on the electrodes and/or find rust on the threads (assuming it wasn't slathered in anti-seize). Other symptoms include a plugged up heater core and radiator, a washed out O2 sensor, thermostat bolts rust welded to the intake, crappy looking coolant and an idle that is never quite perfect. Compression is usually normal (mine was) - a leakdown test is a better way to isolate it. If it is leaking, fix it - a lot of these started weeping under warranty (if the complaints that were filed with the NHTSA is any indication) and if it goes on long enough you can end up with a groove between the cylinder and the nearest coolant hole.
