JRex

So the story goes...

The engine temps are perfectly fine during normal daily driving for the past year, but once I turn on the A/C the car starts to get warm. I didn't think anything of it, maybe just a bad thermostat or radiator cap, until yesterday. I got on the interstate to drive a friend to pickup a car. Well after about 5 min of interstate driving the car started to get hot so I blasted the heater and tried to stay out from behind cars which helped keep the temps down until I got where I was going.

Go home yesterday and bought a new thermostat to put in the car. Opened it up to find that there was no thermostat...so I put it in there and sealed it up. Topped of the fluids then went to drive the car, didn't make it a block before the car started to overheat.

What could cause this? Could it be a head gasket although the temps are fine during normal driving? Clogged radiator? I'm stumped.

Car has a stock Ka24de.

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sidelight

on the box of the thermostat, there should be a number as in: 160, or 170 or 180; If it says 170, that is when the thermostat starts to open, (farenheit). The thermostat opens all the way when the coolant/water gets hotter. Even though the ka24de on s13/ s14 only has 160hp at the crank, and is stock, They are well known to over heat.

JRex

It's a 170.

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sidelight

To test a thermostat, you put it in boiling water,; with a digital thermometer/ or temperature probe. Anything less than 170 farenheit, the thermostat is close, It starts to open once the coolant/water reaches 170. If not, then it's faulty.

If the vehicle had no thermostat when you took it apart, ; the temp will go higher than normal even if you put a working thermostat in.

The job of the themstat is to all the time keep the motor temp at a specific range.
One is not able understand this, untill they put a thermstat in boiling water to observe how it opens. Yes it may take some time for the water to boil in the pan on the stove.
If the home owner doesn't permit this, then get a plastic container to put the thermstat in, boil water in a pot.
Pour the hot water in the container, and the opening of the thermstat is shown.

JRex

Went ahead and replaced the radiator, still nothing. Anyone have any ideas?

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sidelight

The radiator, ;;was it new?, how much more water/coolant can it hold?

If it is new, and holds more water/coolant, ; You saw the thermostat open with the test, the car has a fan behind the radiator; then I guess it is the water pump.. The reason for not getting a used radiator, is that they may have rust in it- which leads to clogging-- All water ratio cools better then coolant, but leads to rust. 100% water should not be use when it is freezing cold.

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endtime fighter is I and a few others

nismoracingsx

ha, I don't run a thermostat in my 240 for a reason..
if you pulled the housing and there wasn't one in there, previous owner might have been delaying a leaking headgasket.

food for thought.

onevia drift

what did the coolant look like when you drained it or whatever. If its a red/orange/brownish color then u have some rust action goin on. Try doing a legit rad flush and see what happens.

JRex

The water was brownish so it defiantly had some rust action going on. Replaced the radiator with a new one, thermostat was working correctly. The water is pretty clear now but the car still heats up with the A/C on. Thinking the head gasket is toast or could it be the water pump?

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JRex

Alright well I'm officially out of ideas...I've replaced the radiator, rad cap, thermostat, swapped the fan for 2 12" electric ones. Still overheats with the A/C on.

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Sam_Well.13

maybe water pump? water pump could be faulty and no pumping out right anymore when engine has more load to it.

JRex

That's the only other thing I can think of. Cause if it was a head gasket it would overheating normal driving too correct?

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Sam_Well.13

yes. and you would get your oil all milky.. check under oil cap if its moist or white and milky.

NINJASPY

bleed the air out of the system. from the greenish(?) valve thing on the right side of the radiator hose. that solves 50% or more of the s chassis overheating problems. even if you top off all the fluids, if you don't bleed the air out at the bleeder location it can still overheat.

PrawjektSilvia

If you drain the antifreeze and refill with the heater valve closed you leave a possibility for an air bubble in the heater core. My recommendation is to open the heater valve, drain the antifreeze, and then when refilling, raise the front end of the car to ensure no air bubbles in the system. And of course, use the bleeder valves...always use the bleeder valves...

junn

have you ever considered it might be the temp sensor

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JRex

The oil looks fine. I've already bled all the air out of the system, so I know that's not the problem. Haven't thought about the temp sensor yet.

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jspaeth

If the car was already wanting to get hot with NO thermostat, then the thermostat is NOT the issue.

Come on..........

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Daily driven

JRex

When I went to replace it I realized it didn't have one so I figured that wasn't the issue.

It seems to only start to get hot when going up an incline?? I'm clueless at this point.

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S14DB

Get some RTV and pull the water pump to see what condition it's in.

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Comments should be taken as Opinions not as Statements of Fact

NINJASPY

have you bled the system from the bleeder valve?? Bleeding from the radiator cap won't do the same job.

overheating on a incline just means theres more engine heat created from the engine working harder, OR you there is air in the system.

jspaeth

That screams that there is air in the system that is making its way to the front of the head near where the water neck is when you go up an incline.

If the air bubble is big enough that the coolant doesn't fill up to the bottom of the water neck, then even though the pump is spinning, it's not going to push that fluid out into the radiator.


Sounds like air bubbles.

Jack the front of the car up as high as you can, and then run it with the rad cap off and you will probably see that there is a lot of room left to add coolant (bc you probably have a ton of air in there).

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Daily driven

JRex

I've ran it with the cap off, bled it through the bleeder system and everything. I did more driving around town today and it still started to overheat after the car got hot enough. I might try bleeding it one more time to be safe.

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motoxris

Start with the easy things first.
When you change your change your coolant your supposed to keep the heater in the on setting to allow the air to exit. When I did mine I didnt get all the air out and it over heated a block down the road. Whent back need to put some water in. Did this 2 or 3 times. Then it was fine.
Next I would change your sensor. Its 15 or 20 bucks. Then maybe the gauge. I pulled my cluster out like 5 times now. I can do it less than hour now start to finish.
I would make sure your car doesnt smoke or anything like that. Even if your car doent show milky water or oil it doesn't mean you dont have a blown head gasket. My brother drove on a blown head gasket for a long time before doing an ls1 swap. He wouldnt run a thermostat, but he had to put in water once in a while.
So I would try those couple of things first. And dont jump to conclusions with major repairs.

JRex

I think I found the culprit...lol

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JRex

Well the water pump was ALSO not the problem.

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gonshik007

Make sure when you bleed the system that your heater valve is turned to hot during the bleeding of the system. Do you have an overflow tank?

JRex

I've bled the system several times after replacing stuff. I know for a fact that isn't the problem. Yes I have an overflow tank.

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stealthsr20

i still think you have a head gasket in your midst, look at that thing!

zstylelowrider

It's funny that no one mentioned pressure testing your cooling system. I would start with that. If it holds pressure you can rule out a head gasket. I wrecked the front end of mine a lil bit and broke some of the plastic air guides in front of the radiator and noticed mine got a lil hotter from just that. And when all else fails replace with oem parts. I've come to learn that Nissan's are tempermental and really like oem parts.