I drive a 99 eclipse n/t and i currently have,headers/intake/catback. stock internals. about three days ago i noticed that my car was overheating when taking it to 6 to 7 RPM, when i would let go of the gas the temperature would then decline. Today the same thing happen while i was driving in the freeway, i was driving about 65 in 5th gear then drop it to 4th and took it to about 6 rpm and then while still in 4th gear i let go of the gas and kept in at 4 1/2 rpm for about 20 secs, look at my temp gauge and notice that the temperature was above normal temps so i immediately shift to 5th, little by litte the temp decreased to normal. When i got home I check the upper and bottom rad hose, both were hot, also i noticed that both fans were working fine, the oil level was normal and the antifreeze from reservoir was at full. Now I currently changed my thermostat thinking that was the cause of overheating issue but i guess i thought wrong. Im thinking it might be my radiator, what do you guys think, any feedback would be greatly appreciated. Thanks in advance.

How high on the gauge did the needle get? Temperature increases should be expected when you're working the car, but 3/4 + up the gauge is excessive.

more the engine spins the more heat it makes I only overheated at high rpms, going up a hill or idling in traffic #1&2 too much load on the engine too cool it #3 no moving air to help cool it

I think there are 2 possible problems. sticking tsat or a clog in your radiator I have had both problems. both are cheap fixes.

about 3/4 of increase temp.

Did you check coolant level in the radiator, or just the overflow bottle? That plastic bottle means dick. Wait for the car too cool down, take off the radiator cap, fill as needed. Then start the car with the cap off and let it idle until the t-stat opens. Add coolant as necessary. When it stops bubbling and all that, put the cap back on it tight and take it for a spin.

Sounds to me like air pockets in the system.

Has any one had an issue with their temperature gauge not working? For the 3 years I've owned my car I has NEVER gone above 1/2 on the temp. gauge. Now when I barely turn on the car it works normally, it slowly increases from zero to the middle when it warms up, but Ive never seen it move beyond that.

I guess what Im trying to ask is: What would cause the gauge to not mark anything above 1/2 way on the gauge? Faulty termostat? Im only worried because when I run the car hard, and I go out and touch the hood its "hot" and I get that "smell" that signals overheating but the gauge doesn't budge. Both my fans do work, and in these instances I hear them turn on, but still, the needle is stuck half way :shrug

Sorry, for derailing your thread OP.

before I had overheating probs it never moved from 1/2 after I fixed it (tsat and a new radiator) it has never moved past 1/2 and this is in Calfornia valley and Hawaii heat no probs. I guess the one thing are cars do well is cool the engine.

Hot humid Louisiana. Mine has only gone above 1/2 when their was a problem.

My car has been trough every possible overheating scenario you can think of. I recently had a similar one as you mentioned with the engine overheating at high speeds. Turned out to be the radiator had a leak therefore low coolant level. Radiator had to be replaced.
Whenever i had issues with the thermostat it would overheat at idle, since yours only does it at high speeds/revs..i'd lean more towards low level of coolant/radiator issue.
Just my 2 c.

Well first check the actual coolant level under the radiator cap. It should be right up to the top. If not add.

Then

replace the radiator cap. (If the seal is bad you don't build the correct pressure, and pressure is what raises the boiling point of the coolant)
caps go bad all the time.. cheap part.

Then replace the coolant temp sensor for the gauge (there are 2, one for the ECU, one for the instrument cluster/temp gauge.



The gauge should NEVER go over 1/2. for everyday driving.
Even playing hard it should still never get there

and just for reference when the thermostat is bad your car stays cool (might raise when accelerating, then drop down to cool again). The thermostat is designed to fail in the open position.

Originally posted by mcgyvr
The gauge should NEVER go over 1/2. for everyday driving. Even playing hard it should still never get there

Thank you for mentioning this. It's a FACT.

The temp gauge in the cluster is designed to stay right in the middle of the range unless the car is either cold or on the verge of overheating. From what I've read, the reasoning behind this is to prevent excessive maintenance inquiries from owners.

"My friend Joe has the exact same car and his doesn't get nearly as hot as mine. What's wrong with my car?"

Sure, they'd love to charge you $75 to check it out for you, but it's really a pain in the ass they could never really iron out. The important thing is to keep the system maintained. If you're that concerned about coolant temps and want to see them live, invest in a proper coolant temp gauge.

Press on.

I currently replaced my Radiator and my thermostat and Rad cap and yet the car still passes the 1/2 mark. I see the needle rise for ex: when i shift to second at 6k RPM same for third all the way to 4th at 6krpm, i did just about everything i could do, both fans work fine, and rad and THERMOSTAT are NEW COOLANT is of high quality, dont know what else it could be. after i had finish installing and refilling coolant in rad and resorvoir, i check for leaks and everthing turned out to be fine, i test drove the car the same and yet i noticed the needle rose abit above 1/2 not as much though and then it dropped to 1/2 instantly. Well the following morning i checked the resorvoir for coolant and noticed it was below mark. recheck for leaks but nothing unusual, i refilled the coolant Resorvoir to mark and drove it a few times that day, coolant Resorvoir seemed to stay at mark for about 3days, on the 4th day early in the morning, i check the coolant resorvoir and to my suprise the coolant was again below mark, the odd thing is that there are no leaks to be found. No Leaks from RADIATOR,HOSE, OR WATER PUMP. one day i noticed the needle rise very slowly while my car was parked then i heard the fan come on and temp needle than stayed constant at normal. ANY FEEDBACK WOULD BE APPRECIATED, THANKS IN ADVANCE

Headgasket.

Originally posted by ghostR1
I drive a 99 eclipse n/t and i currently have,headers/intake/catback. stock internals. about three days ago i noticed that my car was overheating when taking it to 6 to 7 RPM, when i would let go of the gas the temperature would then decline. Today the same thing happen while i was driving in the freeway, i was driving about 65 in 5th gear then drop it to 4th and took it to about 6 rpm and then while still in 4th gear i let go of the gas and kept in at 4 1/2 rpm for about 20 secs, look at my temp gauge and notice that the temperature was above normal temps so i immediately shift to 5th, little by litte the temp decreased to normal. When i got home I check the upper and bottom rad hose, both were hot, also i noticed that both fans were working fine, the oil level was normal and the antifreeze from reservoir was at full. Now I currently changed my thermostat thinking that was the cause of overheating issue but i guess i thought wrong. Im thinking it might be my radiator, what do you guys think, any feedback would be greatly appreciated. Thanks in advance.

:thumbsup Excellent thread, about time someone posted this about our radiator.

I own a NT also, mines an ATX 97 GS, I've been told if the needle stay at half or below this is good.

Use REDLINE WATER WETTER its les than 10 bucks at Advance, drain your coolant bottle abit and put the whole REDLINE bottle in the coolant bottle make sure its not past the half line on the bottle.

Always make you keep your fluid in the coolant bottle at half mark, it not Good to fill up to the top. Reason, is that when your radiator get hot it drains to the coolant bottle and back into the radiator, proper circulation.

Mines always at half but, I do know for a fact that my radiator needs replaced, its pretty bad but its okay. I'm very cautious, with my DSM and I only raced my Dsm one time before I had to change my timing belt and water pump. This was head to head against my brothers Mx6, I had three lenths on him , not bad for a first timer, he talked shit about his ford engine, so I had to walk him. this is older brothers job. LOL

Anyways, what does it do when you have your sitting at idle in Neutral.Does it still go over half. Only I could tell you is have a friend look under your car when you sit in park/neutral, and rev. your engine up to see if it the temp. needle goes pass half or starts to over heat. Look in your HAYNES book complete tear down and rebuild of these cars. if you don't have it go get it read front to back and make it your bible, lol

I'll look it up there's a trouble shooting section in it and I'll repost what find out..

don't know about the headgasket, could be a bad hose that's got a small leak or just expanding too much, air in the system sounds really likely to me. I personally have only seen anything over just shy of halfway up twice and those were both hot days at the track running hard laps for 30-45 min stretches and it just barely crept over the halfway mark and I was being bad and occasionally tapping the rev limiter before upshifts.

Edit: hell, the brakes were getting too hot before the coolant temps were too high

thanks, i'll look into that.

thanks, I really appreciated.