Engine drinking coolant.

[Joey GT-R]

Fix Joey's Car Month continues....


So 2 weeks ago I was in the drive thru and I notice what looks like steam coming from my car, but I was behind a V8 SUV so I'm thinking it's his exhaust gas. A week later, it happens again after I shut off the car. The steam only comes off for about 5-10 seconds, then it's gone, so I can't even pop the hood in time to see where it's coming from. Based on the sound I think it's the hose directly connecting to the radiator but I could be wrong. Engine temps still showing normal at this time. Then a few days later, the engine overheats excessively fast after about roughly 3 minutes of driving. I pull over and add about a quart of coolant. It overheats again, but very slowly with the needle never reaching the top. Then, as I pull into walmart to buy more coolant, temps drop instantly. I added another 3 quarts of coolant and for the next week, everything is fine again. Today, I notice the temp gauge running very slightly higher than normal. It raises again slightly but only till about 3/4ths of the temp gauge itself; with the wind coming through the bumper keeping temps normal. I'm going to add another half a gallon of coolant tonight, but I can't/won't buy coolant once a week.


I've continually went under the car and can't find an ounce of coolant leaking anywhere. So I'm thinking something is failing. Headgasket? Thermostat? Water pump? Can radiators cease to work even if there's no leak? I'm taking the suggestion of doing a coolant system pressure test, but beyond that I'm clueless.

[SOHC-FTW]

To test for leaks do a pressure test.

For head gasket issues/concerns best bets to do a leak down. Normal sign of a HG or warped head/block is milky'ness in the oil or coolant.

[cloudasc]

How full is your overflow tank? When my headgasket was leaking, I would get exhaust gasses that would pressurize my coolant system, forcing the radiator cap to relieve pressure, and dump coolant into the overflow bottle, which would then overflow, eg the loss of coolant.

[CB7 Coupe <3]

is it burning any smoke ? or just steaming from the bay ? and do your radiator fans work ?

[Joey GT-R]

I checked the overflow tank and it's empty. I'm still trying to get the pressure test done. I have seen no smoke, just the steam...or maybe it's white smoke? It seems too thin to be smoke. Plus as I mentioned before you hear that "boiling" sound. The fans just occurred to me. I know my a/c fan doesn't work; which is part of the reason I don't have a/c so next time the car is running I'll see if the coolant fan cuts on at all.

[reklipz]

You're on the right track I think. But because your overflow tank isn't filling up, you either have a failed radiator cap or a leak somewhere else in the system. It's either being burned up in the combustion chamber, or it's leaking externally somewhere in the bay.

Just an FYI: the fans are controlled by a different temperature circuit than the one that gives the reading on your dash. Though, they are both sensed at nearly the same location in the system.

Though the fans may not be working properly (I always forget how they are supposed to operate, so I won't comment officially on that), the other symptoms you note indicate that that would be a secondary issue. Find and fix the leak first.

[dj_ender]

It's pretty simple, you're burning it or you're leaking it. Have you pulled your plugs and see if they are wet? Loosing that much coolant leads me to believe you have a leak, have you check the coolant neck under the dizzy? The hoses under the IM?

You can test the cooling fan by pulling the plug from the thermo switch on the thermostat housing and jumping it just like you would the service connector. The fan should come on immediately. Try driving around and see if the operating temp stays at normal, if it does, good change your switch is bad and you're cooking the coolant in the water jackets. If it doesn't change the temps, I would start looking at the water pump and thermostat.

[Joey GT-R]

Remember my video in my ongoing idle thread? That water sitting on the crossmember, it is in the area of the coolant neck under the dizzy. I wonder if that is a leak. But the angle is so crazy I'm not so sure. I'll pull the plugs and see what happens. If they are wet what does that mean? I'm not familiar with jumping the thermo switch can you enlighten me?

When I drove around today temps stayed fine; right about middle of the gauge. It's starting to get hot in Florida as we move closer and closer to April so I was kinda nervous, I sat at about 3-4 intersections and everything seemed ok.

[dj_ender]

I do not remember that video, I'll try and find it. You can look under the dizzy and see if the tranny casing is wet. That could even be where the smoke was coming from, the coolant CAN reach the down pipe from that leak.

If the plugs are wet there's a vary good chance you're burning coolant in the cylinders. Unplug the connector from the switch on the thermo housing, and jump the connector with a paperclip. Normally, the temp needing should be closer to 1/3 of the way, not halfway. Try jumping the connector and drive around for awhile and see where the temps stay. I can't find the specs to test the switch with right now. But in all honesty, I'm going with a small leak, and I'm betting on the coolant neck under the dizzy.

[reklipz]

The way the book says to test the two switches is to suspend them in a pot of boiling water and see at what temperature they operate (with a thermometer). You may need to adulter the water with something to test switch B, as water boils before it reaches that temperature.

Radiator fan thermoswitch at 90 degrees centigrade, and the other switch at 108 degrees centigrade.

[GeoffM]

From my personal experience:
Look under the dash behind the radio.

I overlooked wet floors because it's winter and I have a leak somewhere.
I don't have a sense of smell, so when it got really bad I couldn't smell the coolant.

[Stoner51]

That leak in the video is right below the FITV. On the bottom of the throtle body. Could be either one of the hoses or the gasket that mates it to the throttle body. Or there are two screws on the bottom of the valve, well actually facing the front of the car. Mine leaked there once.

If you can smell the coolant you have a external leak. Coolant has a sweet smell to it.

Mine leaks a little from one of my IACV hoses. I prob just need to tighten the clamp. No where near a gallon a week though.

steve

[dj_ender]

From my personal experience:
Look under the dash behind the radio.

I overlooked wet floors because it's winter and I have a leak somewhere.
I don't have a sense of smell, so when it got really bad I couldn't smell the coolant.

That would be your heater core leaking.

[wed3k]

That would be your heater core leaking.

no shit?

try starting the car with the rad cap off and see if it shoots out. hope you didn't over heat it too bad, might need new rings.

[dj_ender]

no shit?

Your attitude isn't needed. The OP wasn't aware of where the leak was coming from, other than behind the radio.