Overheating in the cold

[g6civcx]

Whoever guesses this one right gets a cookie. I'm stumped.

-5 degrees freezing cold. Normal freeway cruising and the car starts to overheat. Steam comes boiling out of the coolant reservoir and onto the hood. I shut it down and cranked the heater. This is a stock S13 SR redtop with leakdown and compression fine across all 4 cylinders. No blowby.

I checked and the only coolant splash was around the reservoir/battery box area. The radiator and hoses were dry. The head was also dry.

The only thing I can think of is either the thermostat is stuck shut, water pump is dead, or my head gasket is blown.

I pressure tested the cooling system prior to this, and properly bled it. Any thoughts?

[markyboi]

check oil and coolant




probably thermostat

[g6civcx]

Originally Posted by markyboi

check oil and coolant




probably thermostat

I always top off oil and coolant. Matter of fact, I checked them the day before it blew off like that.

What would oil have to do with it though?

[jrmiller84]

If you're running low on oil it will start to overheat. I'm not sure that's your problem though, could be if you have a leak I suppose.

[HalveBlue]

Hmm...interesting.

Did you check the rad host coming from the radiator and going to the thermostat? If it's cold it means that coolant isn't flowing through the radiator probably, and that's usually due to air in the system. The solution in that case is to bleed the system.

I doubt it's a headgasket. If it was, you'd see the coolant in the overflow resevoir disapear over time.

The only other two culprits, which you've already mentioned, is the waterpump or the T-stat.

The only other thing that I could think of is some sort of blockage somewhere in the coolant system, like the heater hoses in the back.

Good Luck!

[irax]

obviously if water pump is bad, it would over heat. but you would of noticed it leaking from the willow hole or whatever its called.

I think it may be the tstat or radiator cap.
if tstat fails it may not open at the right time causing over heat
if radiator cap fails, pressure wont build up in the system and the water pump wont move water.

[Sir]

had the same thing, only it was caused by a big hole in the radiator
i used 50/50premix, so it should've been fine, but it wasnt.

[g6civcx]

Both radiator hoses are hot. They're brand new Samco hoses.

I also bled the system very meticulously. The heater core is brand new and heater hoses are as well. There is no blockage in the heater hoses.

I always check coolant level and the reservoir was fine the day before. It was very sudden.

Right now I suspect the thermostat, water pump, and radiator cap. I'll replace the thermostat and cap since they're easier. I don't notice any leak from the water pump.

I'll check oil level again, but I usually add 3 quarts because the FSM calls for 3.5, but usually there's still half a quart left in the engine after draining for several minutes.

[Silverbullet]

1.) dead water pump?

2.) frozen water in cooling system? I know some people put in a bad mixture of coolant to water ratio, and what happens sometimes is there is more water than anti-freeze. The artic nonsense of NoVA is perfect for freezing things in your car this time of year.

[Gnnr]

Originally Posted by g6civcx

The only thing I can think of is either the thermostat is stuck shut, water pump is dead, or my head gasket is blown.

Hmm, those are my guesses too. LMK how it goes after you change the cap and thermostat.

[MELLO*SOS]

In weather that cold you could have a frozen chunk of ice somewhere due to not enough coolant? What ratio did you mix the coolant and water at?

Also, what kind of radiator fan are you running -- efan or clutch fan? If efan it's possible that you have a short.

Has it blown over any other times, before or after this time?

[irax]

Originally Posted by mello88

Also, what kind of radiator fan are you running -- efan or clutch fan? If efan it's possible that you have a short.

In -5* weather I don't think fans running or not would of made a difference.

[MELLO*SOS]

Yep. grasping at straws is the saying I think

[drftwerks]

if you think its the tstat and rad cap and pump, replace them already, they are cheap to do , and if anything it will be done for later

[aznpoopy]

replace cap +1

rad cap increases boiling temperature of coolant
failing rad cap makes boiling point lower
that can cause your system to boil under load and pop the top of the overflow tank

[RightWheelDrive]

I had the exact same problem.

When you are overheating, turn the heater full blast and watch if the temperature goes down. If it does, it's the radiator.

It is probably clogged/corroded and cannot keep up with the cooling at freeway speeds, regardless of how cold it is. I had to drive through the summer like this, 90 degs and heater full blast(fun...). I also drove in the winter in ~30 degrees. That huge difference in temperature only gave me an extra 5 minutes before it would start to overheat again.

I finally got a Koyo and there have been no overheating problems since, finally. I did change the thermostat, cap, and water pump but that made no difference. Try getting another radiator to test it out but as always, you can't always trust used parts. Also make sure your overflow tank is clean inside or else it will suck up particles and ruin the party thats going on in your radiator. That is how mine got clogged, making my track day a track morning..

[Chrischeezer]

after market fans? or stock?

[jrmiller84]

Originally Posted by irax

obviously if water pump is bad, it would over heat. but you would of noticed it leaking from the willow hole or whatever its called.

Sorry, had to do it.

[HalveBlue]

^^ Hehe, Willow kicks ass!

But you know what doesn't kick ass? Typing a reponse in a thread about engine overheating and then having your own fucking engine start overheating.

That's just ironic.

Boo.

Boo, I say.

Stupid engine.

[irax]

note to everyone,
buy a koyo radiator
or when you buy the car flush the coolant and replace; cap, tstat, pumps, and hoses. i have a koyo radiator, i only turn on the fans to ease my mind.

[g6civcx]

I have a stock SR rad and clutch fan with shroud. It does not overheat in 100+ degrees on the track, which was why I was surprised when it overheated. It has never ever done that before. I generally run a 70/30 water/ethylene glycol mix.

Turned out it was the thermostat sticking closed. I think the cold weather just made the spring give out and stuck. Replaced the thermo and it runs like a top.

Lesson learned. Replace thermostat when replacing rad hoses. Flush coolant and bleed.

Thanks to all those who replied. +rep for you all.

[irax]

im glad your car does not over heat anymore

[NemeGuero]

Damn, I'm late.
I was gonna say Thermostat sticking closed...

[g6civcx]

I was procrastinating because the waterneck is a little difficult to get to. I was eventually going to put in a Nismo thermostat, but never got around to it.

[Gnnr]

Cool, glad you got it fixed.