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Overheating problems/symptoms


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Good point, this theory could explain why it's so sparatic. If it's dependant on vehicle speed, wind speed, wind direction and engine load then there are too many variables to cause it to overheat at the same rate all the time.

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I have 2 ideas, the first, alot of people are gonna completly disagree with me, but this is just a test, not a fix. TEST

 

Take out the thermostat. Drive without it, if that fixes the problem, then you may need a new thermostat. You may be like me, they way that you goto advanced auto parts or such places to buy most things? If so, I've see people buy a thermostat from Autozone, and they crap out within a week. Sometimes the quality is crap, sometimes its good, its the luck of the draw.

 

Are you sure your gauge is right? I had a wiring problem one time on my ZX, that it would say I was overheating when the motor was just at operating temperature. At times it would even "overheat" by the time I got out of my nieghborhood, about 1/2 mile.

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I can hear the coolant boiling when it gets really hot on the guage, so i tend to believe it.

 

And the thermostat should be fine, it's a quality replacement part bought from a european part supplier that has a very reliable history. Plus it was overheating with the old thermostat as well.

 

I've though about both things so don't think it's stupid possabilities, just ones that i've gone over.

 

Looks like i'll have to either buy a POS electric fan from a local store (kragen, autozone) or i'll have to by one from summit wich will take longer to arrive.

 

If I go with summit I'll probly get a 14 inch flex-a-lite syclone and a flex-a-lite adjustable fan controller. I'm about to start researching and seeing what other people use on thier Zs.

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so you narrowed it down to the fan? What did you top the radiator off with? Straight water, 50/50 mixed coolant?....ect?

 

I don't believe the pressure exerted from a radiator car will help straight water, if anything, I'm pretty sure it causes water to boil faster. Perfectly mixed coolant isn't sufficiant enough either. Its the pressure+coolant=sufficient cooling. For every PSI on coolant, it raises the boiling temperature by a certain degree. Make sure that your coolant is pre-mixed right.

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my mix was 40/60 when i first put it in, and i was only filling it with water. By the looks of it right now it's probly 60/40.

 

Coolant mixture could be making it hard for the car to cool down once it's overheating, i have thought of that. But that's usually not the root of a overheating problem.

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I have an elecric fan with a $$$ electronic thermo switch... with 2 stages and 2 fans.... along with an "emergency" switch for full fans in the car...

 

I have inadvertantly run the car with the entire cooling fan system disabled... I can tell you that the temp rises slowly once I come to a stop(3-5 minutes to get near overheating)... I can turn on the heater if nothing else and cool the engine considerably while sitting at the stop light...

 

The systems act very strangely when they do not hold pressure.... It has already been mentioned that when you car is low on coolant the guage will often read cold... and then suddenly JUMPs to overheat when you rev the engine or it simply begines to boil over on it's own.... this is because the sender is high and dry... then it suddenly gets a wash of boiling water over it and spikes the guage....

 

OHH... straight water is a nono unless you buffer it to reduce corrosion....

OHH... and increasing pressure always raises the boiling point... of anything...

OHH... technically straight water is a better cooant than water/glycol mix... It boils faster but cools better...

 

I have observed that the electric fans will never turn on when I am cruising down the highway... airflow through the radiator at speed is MORE THAN ENOUGH to properly cool the engine....

 

for the guy who blew his engine trying to start it with brake cleaner.......DON'T run the car for any period of time without the thermostat in place.... the thermostat never fully opens.... it provides a restriction to the radiator to ensure that water contiues to flow through the engine... if you remove the thermostat YOU MUST REPLACE IT WITH A "TEST PLUG" that has a metered hole in it to ensure water circulation through the engine block.... running you engine without a thermostat is akin to running it without water.... DON'T learn the stupid way....

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.....for the guy who blew his engine trying to start it with brake cleaner.......DON'T run the car for any period of time without the thermostat in place....

 

Was this a personal attack at me? Just in case you didn't pay attention

(which I don't think you did)-my motor never blew, I popped a hose, that is all.

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srry... I just couldn't resist...

 

running the engine down the road with nothing in the thermostat housing is one of those old timer/ eveyone who knows anything about engines kind of nonos....

 

It really pains me to see these kind of suggestions flying around.. for your own sake...

 

Hey.. I am not trying to hurt your feelings... If we were in the same local club I would be saying this same thing to you with a smile and a wink...

 

Hey... look at it this way.. no matter what... you are willing to try what comes to mind... most people just scratch their heads and take it to a mechanic..

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It always surprises me when people work on their cooling system, replace parts, and coolant but never consider to chemically flush the system. The inside of your cooling system may look OK but, a very thin layer of corrosion will build up over time and it will prevent good heat transfer from the block to the coolant. Just some food for thought!

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Yes I understand the process... BUT, overheatiing issues surfaced overnight, not slowly. I'm much more inclined to first think it's something I did when I was working on it.

 

Update: Upper rad hose is bad, overly soft. I don't know if it's leaking while under engine load, but just sitting it swells up quite a bit. I'll be replacing that tomarrow, and hopefully I'll get my fan soon. I've already got my fan controller w/thermostat from summit (came in less than 24 hours)

 

And I'm definatelly loosing more water than before. I'm going through about 1/2 to a full gallon a week depending on how much I'm driving. I just gotta find this damn leak.

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Gollum,

Put the mechanical fan back on it and make sure the system is full of the correct water/glycol mix and I bet your overheating problems disappear.

 

My guess is the lack of a fan caused the initial overheat which left the system low on coolant. The low coolant condition then caused and continues to cause all of your other symptoms.

 

Do this simple experiment, report back to us with the results and then we can continue the discussion about all the other probable causes, assuming the problem doesn't disappear.

 

Once you've resolved this for yourself, if you still want an electric fan save up enough for a good one and wait to remove the mechanical until after you have the electric in hand.

 

Wheelman

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I understand that low coolant will cause lots of problems, and I'm hoping that getting a fan on it will fix it.

 

But why put the mechanical back on when I'm proibly going to have the electric one i've already bought show up in the next 2-4 days? I don't drive every day, and if I keep the distance under 60 miles round trip the car won't overheat as long as the system is full.

 

At this point I just don't see the point in putting the mechanical back on when it'll just have to come off in the very near future.

 

Oh yea, mrinsane, you're insane... go figure :D

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The car is overheating because there isn't enough airflow through the radiator. Remember back several posts you said the temp remained good when you where moving at a decent speed, that's because air was moving through the radiator. You also said sometimes even on the highway it ran hot, that's because the system was low on coolent.

The radiator is a liquid to air heat exchanger that relies on air flowing through it to move the heat away so cooler air can absorb more heat and move it away. If there is no airflow the heated air around the radiator gets hot enough to not absorb anymore heat so then the hot coolent just recirculates back into the engine and gets hotter. Pretty soon the coolant gets hot enough to boil and turns to steam which is released by the radiator cap due to high pressure. Voila, you loose coolent and the system gets even hotter.

 

Put the mechanical fan back on and I bet your problem disappears.

 

Wheelman

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I'm not saying your wrong, and no offence I didn't learn anything from your post. The hardest thing about all this is explaining all the different things that have happened.

 

Ok, just the other day I drove about 50 miles and the coolant system was fine, full and keeping the car cool. I was to the freeway by the time the car was even fully warmed up. I never went less than 40mph and when I was about 5 miles from my destination the car started to heat up. By the time I got there it was quite overheated. I've been carrying extra coolant with me to keep things on the safe side. When I was headed back home I filled it up and the coolant system took in nearly a gallon.

 

I hope, even pray that just a fan will fix it. But i'm not going to be suprised if it doesn't. Again, i'm not saying your wrong. I KNOW that the fan is at least part of the problem. And if it IS the only problem I'll thank you and hybridz for yet another problem solved. If not I'll still be here needing help on locating leaks. (there's still the possability it's the rad cap, but it looks fine. I might buy a new one just for good measure)

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OK, so maybe you do have a leak. I didn't pick that up from all your previous posts. A fan will definitely help but based on your last post probably not solve your problem.

 

My Ford Ranger had a similar problem, no lost coolant though, but it turned out I had to replace the radiator because it was plugged due to corrosion in the system. The truck wouldn't loose coolant, it would just run hot and then overheat. After replacing the radiator the problem disappeared.

 

Wheelman

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NOTE TO EVERYONE (though I m writing this thanks to wheelman):

 

I appologise for my lack of description. I've gone back to read all my posts and I havn't been describing my situations very well. I'll try to give a better run down on what it's been doing tomarrow when I've got more time to think about everything it's done.

 

Maybe it's a leak, maybe not. I won't know for sure until I get a fan on it.

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Ouch harsh words.

 

But i've been working on cars since before I was a teenage, even rebuilt a few motors in my time. I dont' consider myself a mechanical idiot.

 

Plus all the shops i've dealt with can't seem to do squat on a car unless they can hook it up to a scanner. Good reliable mechanics are extinct around here.

 

EDIT: Oh yea.... Havn't you heard that the average national wage for a musician is less than minimum wage? (even when you take into account that people like brittney spears make millions)

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