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car warms up fine

after i reach 100km/h my car has been losing some heat...any one have any ideas?

i got a new water pump/thermostat/timing belt done a couple months ago.

How is your heat set. Doesn't one of the settings use circlated air and the other uses fresh air pulled from outside. If so you might have it set on the fresh air one wich could just mean at higher speeds the air has less time to heat up before entering the car. Just a thought*

If your thermostat is stuck open... THe coolant doesnt get a chance to heat up". The coolant constantly flows instead of stopping @ the thermostat, heating up, then flowing past the thermostat once it opens.

Also check the "air hole" on the thermostat, should be pointed up.

i tried it on both settings...same results...

it slowly lost heat, so i dropped it to 4th gear, doing 90 km/h, then it re-gained heat to normal running temp, so i went back into 5th and it was fine again...this has happend a few times to me.

the car started up fine today and ran fine, but theres obviously something going on here.

i have a spare thermostat layin around, so i'll change it yet again, this is the 4th thermostat ive changed in less then a year. frig.

cheers*

Sounds like really good cooling =D

When you get a new water pump and new this and new that which involves the cooling system, they all generally help it run a little cooler but not to that degree so I agree with Custommx3's post.

I would recomend purchasing what is called a 'Fail Safe' thermostat.

93_mx3_gs wrote:I would recomend purchasing what is called a 'Fail Safe' thermostat.

What is THAT? How would it be fail safe? Nothing lasts forever. The only way it could be fail safe is if there was a back up or something? Correct? I mean if the thermo sticks, then it fails. Open or closed is bad news. Please explain this "fail safe" thermo.

is it alright to just pop open the thermostat housing to replace the thermo without emptyin all the rad fluid, i relieze some will come out, but i dont feel like drainning everything.

Yep, plug and play

Mechanics might say you're suppose to or you should but you really don't. Just make sure whatever you lose you put back in, if any. If you're afraid of air pockets let the car run a few minutes with the rad cap off afterward. You should fill when the car is running anyways so there ya go, what timing!

Ask the designers how it works, I just know the bastard never sticks if it were to faulter, it forces itself open and stays open instead of sticking shut.

I didn't design it nor have the blue print. I don't think they have a federal patent for it not being fail safe.

The thermostat has a design with 2 forks that grab the thermostats "moving" part if it gets too hot and holds it open indefinatley.

Simple design that works.

Well I understand that but what I'm saying is the thermo is still failing right? If its stuck open sure, coolant will continue to flow and keep the engine from overheating, but it would still cause heating problems for the air.

azazel95 wrote:Well I understand that but what I'm saying is the thermo is still failing right? If its stuck open sure, coolant will continue to flow and keep the engine from overheating, but it would still cause heating problems for the air.

Not really because of it's size, it will still offer enough restriction. I just jammed mine open ( 14.99 out the door. ) stuffed it in my car and drove down the freeway on my way to pic up my camera. Anyways, It started blizzarding about 20 miles from home so I cranked up he heat and defrost, No problems.

They call them fail safes for a reason. Just because you don't understand it doesn't mean it won't work. So when you say it's still failing, No it's doing exactly as it's supposed to be doing and not failing.

They call them fail safes for a reason. Just because you don't understand it doesn't mean it won't work. So when you say it's still failing, No it's doing exactly as it's supposed to be doing and not failing.

Actually it is still failing, they design it to stick in the open position in the event that it does FAIL. if it were actually a "fail-safe" thermostat they wouldn't need to design it to lock open because the regulating device would never fail. it's better to stick open than stick shut though. personally i've had better luck with standard thermostats than "fail-safe" ones.

anyways, back to the topic, does your temp guage go down when you are in 5th and go up when in 4th?

my car warms up alright. takes about 5 minutes or so.

anyways...i got on the highway, and ya, when i hit 5th gear, i noticed i was losing heat...meaning my temp guage was dropping to the warm up lines....so i dropped it into 4th doing 90km or 100km or so...and it shot back up...im not sure what to make of this...never seen it before on any car.