Steam from block on cold start.

[havoc1482]

So, as some of you may know I have a Northstar engine. Today my car was dead, I haven't driven it in a few days and it was sitting in single digit temps all day on Friday. I wasn't surprised, seeing as I still have the f*cking factory battery in the car. (I'm too cheap to buy another one, its like $150+)

I jumped it, and as expected the car was idling high because the battery was so low. After a minute of so steam started to rise from the engine block. Smells like coolant (Oh shit). I just let it happen. I watched it with the hood open. I then turned the car off and restarted it to reset the idle back to normal. At this point it started to steam less and less as the temp gauge climbs. It reaches the 200F mark and the steam is gone and everything is hunky-dory. Let the car sit for about 10 more minutes and the temp gauge stayed right on the 200F mark.

So like, is this an early sign of a HG failure? I mean the car has almost 190k on it and this is the first time I've noticed this. The car yells at me for low coolant about once a month and I just top off. So I always knew coolant was leaking or burning somewhere, but I assumed it was like leaky freeze plugs or something. (I read the freeze plugs on the NS can weep overtime)

[Frosty]

In my opinion Havoc, the answer is yes. I mean it is possible that you are loosing coolant through the water pump, the radiator, or heater core, but I think you would notice coolant coming from those locations by now.

Is there any pressure in the radiator or coolant reservoir when you open it? That could be a sign of exhaust gas entering the cooling system.

Have you checked your oil lately? Is it milky at all? If so, then coolant is leaking into the oiling system.

If coolant gets into the cylinders, you could bend or break a connecting rod.

Don't forget that the Northstar uses torque-to-yield head bolts, which means they can only be used once. Than means you need to replace all of them completely along with the head gaskets. I would probably check/replace the thermostat and water pump too. If the motor has to come apart, I would check the timing chain/cam lobes and fuel injectors.. I would also take this opportunity to thoroughly clean the throttle body.

Honestly, 190k miles on the motor is not too bad either. Some sort of major engine work is probably due with that much mileage. Too bad it's happening on your watch.

[havoc1482]

I'll have to do a more thorough investigation, but I've never encountered pressure in the reservoir. How exactly could I check that? Squeeze the coolant tubes? Take the cap off while running before it gets up to temp?? I suppose I could get one of those kits that tests for exhaust contaminate in the coolant.

 

 I also took the oil filler cap off when the engine was running for no real reason and the oil that was being slung around on the timing chain looked like normal oil. I've heard if there is exhaust in the coolant than the temperature gauge can get wonky because an air bubble can pass over the sensor and give a false reading.

[Frosty]

If you open the cooling reservoir and it sounds like you are slowly opening a soda bottle, then you are probably getting exhaust into the cooling system. Go to NAPA or Autozone and get a "combustion leak test kit". It will check for exhaust gasses being present in the cooling system.

Pull the dip stick and check the oil. If it looks like chocolate milk, then you have coolant in your oil.

If you are loosing coolant due to freeze plugs, then you should notice coolant underneath the car.

An air bubble in the cooling system will drive the engine and gauge crazy. Have you noticed any crazy readings from your temp gauge?

 

[havoc1482]

Didn't check the pressure under the cap. I'm too scared to open it up unless the engine is cool. I had a tractor radiator blow up in my face this summer and I makes me uncomfortable lol.

I check the oil. Dunked the dipstick twice and looked into the oil filler at the timing chain, looks like oil that has about 70% life left (According to the DIC since I reset on last oil change).

The temp gauge has never moved over 200F or done anything crazy. It climbs steadily and stays put like It should. I did notice coolant leaking a few times, but if my memory serves me it was under the reservoir area and not actually the engine. Not sure, I'll have to get a test kit for sure though. 

[Frosty]

Open the reservoir or radiator cap slowly once the car is totally cooled off, there is no chance of getting scalded if you do. In theory, the reservoir should not be under any pressure at all. 

So how did the oil look? Like it's suppose to or milky?

Does you temp gauge go beyond 200-220 at sustained highway speeds? If you are going to overheat it will happen mostly likely when you are stressing the motor.

[havoc1482]

I actually took the cap off at 100F on the gauge. No hissing.

Oil looked fine.

Temps never go over 200F and I drive to and from school on the highway on a weekly basis.

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[Frosty]

The last thing I can think you could do is use a "dye" kit. You essentially put a specialized dye into your coolant, run the car a bit, and then you use a special UV flashlight to find the leak.

[havoc1482]

I'll look into it. I wonder if a dye kit will have a bad reaction with the ever so finicky DEX-COOL in the system lol

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[Frosty]

Sorry for the delay on getting back on this Havoc. No, it should not. The dye is not much more than a small vial worth of chemical, so I'd be surprised if there was any sort of reaction at all, except for the ability to see it under UV light.