Its been two weeks since i swaped my Si motor for another Si motor... the problem is that i already changed the thermostat with a medium thermo... 180 degrees... and everytime i drive in the freeway the needle in the temp goes up to almost the H on the gauge..... what problem can i have??? any ideas??? any help will be appreciated...
thanks

 

Did you bleed the system after replacing the thermostat? If not that could be your problem.

 

If you think its a problem with the thermostat, then just remove it. You never said if you had the problem with your other engine or not. Overheating problems are really easy to fix. Provided all your coolant hoses are hooked up properly, the only things that could cause over heating, would be lack of coolant, clogged radiator, faulty thermostat, or faulty radiator fan. <--Is it wired up?


[Modified by Steve Berman, 10:29 AM 8/31/2002]

 

OR a bad water pump

 

oops i knew i forgot something! its too early

 

Well, i know the fan works for sure, and the radiator should be fine because before i put in that other motor the car would never do this.... as for the water pump i doubt it because the motor has less than 40k miles on it... but it can be a possibility... how can i check if its the water pump??? Now that you mention it, i think it might be lack of coolant because my brother told me that he only filled up the radiator with only water, no coolent because he just wanted to check first that everything worked right... so im gonna dilute 50/50 of coolant and water...
thanks

 

that would be a good idea and solve the problem prolly. make sure it is to the top. start your car and let it warm up then recheck level. alos fill the overflow

 

ogm, not to shoot you down, but water is coolant. Its dosent cool quite as good as "antifreeze" but running plain water will not cause your car to over heat by no means. My car runs @ 150f on water in 100 degree weather..

As far as diagnosis.. try this..

Let your car idle to regular operating temp.. (when the fan kicks in) then, feel the radiator hoses. Bottom and top. (* please dont burn yourself) If they are both warm/hot as **** then coolant is flowing. Another way to verify that coolant/water is flowing is to check to make sure teh heater works. There is a (copper i think) pipe that goes into the firewall beind the dash. If its warm, then you know that the thermostat is opening... ..

 

i ran my other car my toyota with just water in the cooling system and it was starting to overheat after driving a while on the freeway,,,after i put coolant 50/50 water it didnt overheaat anymore

 

As a matter of fact the heater does NOT work.... I try to use the heater to bring down the temp but it doesnt blow any hot air... i guess ill be checking the copper hose, i guess the thermostat i bought is faulty.. but either way ill double check again.. thanks

 

Try to narrow the problem down.
If the water pump is bad it will leak or make an awlful noise.
Check the fan to make sure it comes on.
And you just replaced the thermostat, it should be fine.
My headgasket failed, but didnt never give any signs of it. But after a couple of months it finally started showing. Took a friend and i 3.5hrs to change it, and no more overheating problems.

 

Just take out the thermostat and see how it goes. I dont run one at all.
FYI, water makes your car run cooler than antifreeze...